Dairy Nutrition News

Lallemand Animal Nutrition Launches Ruminant Digestive Health Platform

Wed, 22 Apr 2026 14:13:02 GMT

A newly relaunched educational platform from Lallemand Animal Nutrition, rumantdigestivesystem.com , highlights a growing shift in cattle health management: Focusing only on the rumen is no longer enough to optimize performance, health and efficiency.

What Is a Whole-System Approach to Ruminant Digestive Health?

A whole-system approach evaluates the entire ruminant digestive tract, including both the rumen and lower gut, and how these compartments interact to influence:

Feed efficiency
Microbiome balance
Immune function
Disease risk

This approach reflects emerging research showing postruminal function plays a measurable role in overall herd outcomes.

From Rumen-Centric to Full Digestive Insight

Historically, ration formulation and digestive health strategies have centered on rumen fermentation. However, increasing attention is being placed on the lower gut, particularly its role in inflammation, nutrient absorption and systemic health.

To address this, Lallemand Animal Nutrition has expanded its interactive learning platform to cover the full digestive system, helping veterinarians and advisers connect research with practical management decisions.

The platform combines scientific data with applied insights, supporting a more complete understanding of how digestive function drives productivity and welfare.

Key Topics Covered in the Platform

The platform consolidates core areas of ruminant digestive health into a single resource:

Rumen–lower gut interactions
The ruminant microbiome and its function
Digestive development from calf to mature animal
Common challenges such as SARA, liver abscesses, leaky gut and BRD
The role of probiotics and microbial-based solutions

This structure helps translate complex digestive science into actionable strategies for on-farm use.

Using this Platform in Practice

The updated platform serves as a centralized, science-based tool to strengthen both decision making and communication among nutritionists, veterinarians and producers.

According to Lallemand, it supports a more comprehensive evaluation of digestive health issues by encouraging a broader view of the entire gastrointestinal tract. This allows for stronger integration of nutrition and health strategies, rather than addressing problems in isolation. It also helps veterinarians engage more confidently with emerging research, making it easier to incorporate new insights into practical recommendations. By shifting from a compartment-focused approach to a system-level perspective, veterinarians are better equipped to interpret multifactorial conditions where rumen and lower gut interactions influence outcomes.

The platform also functions as a practical communication tool.

Its interactive, visual format helps explain complex digestive processes in a way that is easier to understand and apply. This supports:

Clearer explanations of digestive function
Reinforcement of nutrition and management strategies
More effective discussions around performance and herd health

This improves the likelihood that recommendations are both understood and implemented on farm.

As ruminant nutrition research advances, translating new findings into daily practice remains a persistent challenge. By combining current science with real-world context, this platform helps bridge that gap, allowing veterinarians to apply emerging insights more effectively during herd visits and consultations.

A whole-tract approach to digestive health is becoming essential, and tools that integrate research with application will be critical in delivering more precise, system-based recommendations.

Fatty Liver in Dairy Cows: The Export Problem You’re Overlooking

Mon, 20 Apr 2026 15:29:48 GMT

The transition cow is often discussed as having an energy problem. Cows eat less, demand ramps up and they fall into negative energy balance. While true, this is only part of the story. The bigger issue is a logistical bottleneck: What happens to the fat that gets mobilized? If the cow cannot move that fat out of the liver efficiently, metabolic problems stack up quickly.

Why the Liver Gets Overwhelmed

Around calving, a cow’s dry matter intake drops by 30% to 35%, while energy demand increases sharply. To fill this gap, the cow mobilizes body fat and sends it to the liver. Once there, the fat follows three main paths:

Complete Oxidation: It is burned for fuel to generate ATP (energy).
Ketogenesis: It is converted into ketones.
Export: It is packaged and sent back into circulation to be used for milk synthesis.

When the volume of fat exceeds the liver’s capacity to process it, the system breaks down.

“Lipolysis happens, that adipose tissue is breaking down. Part is going to be used for milk synthesis, part is going to go for complete oxidation and generate ATP and part goes to ketogenesis. The third thing that happens is that triglycerides accumulate, and when the liver cannot keep up, fat builds up in the liver and we start to see metabolic problems in cows,” says Fabio Lima, assistant professor at UC Davis School of Veterinary Medicine.

Choline as the Liver’s “Shipping Crate”

The fundamental struggle for the modern dairy cow is her low capacity to export triglycerides from the liver as very low-density lipoprotein (VLDL). Choline is the key ingredient needed to build the VLDL “package” that carries fat out of the liver cells.

“What we know about our modern dairy cows is that they have a low capacity to export triglycerides from the liver as VLDL. That inability to increase fatty acid oxidation or export is what leads our cows to develop fatty liver. Choline has been shown to be a key ingredient to reverse that,” Lima says.

By supporting the synthesis of phosphatidylcholine, a specific fat-transporting molecule, choline ensures the liver can keep up with the surge of fat mobilization.

“The modern dairy cow has been selected for high production. That creates a demand that makes nutrients like choline strategically important. It helps support that level of production,” Lima explains. “Choline is critical for VLDL assembly and hepatic fat export. And it’s critical to reduce fatty liver risk and minimize its impact. Phosphatidylcholine seems to depend on adequate choline, especially during the transition period.”

Why Rumen-Protection is Non-Negotiable

While choline is present in common feed ingredients like soybean meal, canola meal and forages, it is almost entirely degraded by rumen microbes before the cow can use it. Because natural feed sources rarely provide enough absorbable choline to meet the high demands of early lactation, rumen-protected choline is added to ensure the nutrient reaches the small intestine for absorption.

Despite the clear biological mechanism, the dairy industry is still refining exactly how much choline a cow needs. Because rumen dynamics are complex and every cow mobilizes fat differently, providing a one-size-fits-all dose remains a challenge.

“There has been 40 years of research, and we think, ‘Well, 40 years is a lot of research, we’re probably going to get some clear guidance.’ But we’re still not sure. There’s still the rumen dynamics and how much is metabolized, where it goes. All those things that make it difficult,” Lima says.

Rethink Transition Management

Success in the transition period requires looking beyond the feed bunk. The critical question is no longer just “Is she eating enough?” but rather: Is the transition cow able to handle the fat she is mobilizing?

Instead of focusing only on energy intake, it is equally important to consider how effectively the cow can process and move that energy. Supporting liver health through fat export is one of the most direct ways to reduce metabolic disorders and improve performance in the modern dairy cow.

10 Practical Tips for Milk Fever Prevention and Treatment

Tue, 14 Apr 2026 13:55:18 GMT

Milk fever is still one of the most costly transition cow problems. While down cows get the attention, it’s often the subclinical cases quietly eroding performance that matter most.

To help producers navigate these challenges, we’ve gathered insights from a panel of experts featured on “ The Bovine Vet Podcast ”:

Heather Chandler, a practicing field veterinarian.
Burim Ametaj, an immunometabolism researcher at the University of Alberta.
Megan Connelly, a transition cow specialist with Protekta.

Identify the Invisible

1. Monitor the herd, not just the emergencies

Subclinical hypocalcemia is often invisible, yet it drives secondary diseases and lost milk.

“Blood calcium is an easy thing to look at if we want to be proactive,” Connelly says.

The Action: Pull blood samples from 10 to 12 fresh cows (0-72 hours post-calving) and track the percentage of the group falling below normal calcium thresholds.

2. Watch the cow, not just the spreadsheet

Data is vital, but the eye of a trained herdsman is irreplaceable. Connelly notes many subclinical cases simply show up as cows that “don’t come in and thrive.”

The Action: Train your team to flag cows with reduced intake, lower rumination or generally “off” behavior. Performance dips often precede clinical disease.

Choose and Lock in a Strategy

3. Pick one strategy and execute it flawlessly

Consistency beats complexity every time. Whether you choose a negative DCAD diet or a Zeolite program, the success of the program depends on execution rather than the choice itself.

The Action: If using DCAD, monitor urine pH religiously. If using Zeolite, focus on the feeding rate and dietary phosphorus levels.

4. Respect the 21-day close-up window

A transition diet only works if the cow actually eats it for the required duration. Chandler emphasizes both DCAD and Zeolite programs need to be fed 20 to 25 days before calving.

The Action: Separate close-up cows into their own group 21 days before their due date and ensure they have daily access to the specific transition ration.

Immediate Calving Intervention

5. Time your calcium boluses for maximum impact

Calcium demand spikes the moment the calf hits the ground. Timing is everything.

“You can even give boluses before she calves,” Chandler suggests.

The Action: For high-risk cows, provide one bolus at the onset of labor (or immediately at calving) and a second bolus 12 to 24 hours later.

6. Treat down cows as true emergencies

A cow that cannot stand is a race against time.

“The pure weight of a down cow leads to muscle necrosis quickly,” Chandler warns.

The Action: Respond immediately. While waiting for the vet, roll the cow side-to-side to maintain circulation and ensure she is on deep, supportive bedding. When administering IV calcium, do it slowly and monitor the heart rate.

7. Address the full mineral picture

If a cow isn’t responding to calcium, it may not be a simple case of milk fever. Chandler notes low phosphorus or magnesium are often at play.

The Action: If a cow’s response to treatment is poor, work with your vet to supplement phosphorus or magnesium and review your overall mineral protocols.

Long-Term Stability

8. Prioritize rumen health to support calcium

Rumen stress and inflammation can directly disrupt a cow’s ability to regulate calcium. Ametaj points out many transition cows exist in a chronic inflammatory state.

The Action: Protect the rumen by avoiding sudden starch increases. Push up feed frequently to prevent sorting and ensure the ration contains adequate effective fiber.

9. Avoid over-acidification

While DCAD is effective, more is not always better. Over-acidifying the diet can lead to a drop in dry matter intake, creating a new set of problems.

The Action: Regularly check urine pH. For Holsteins, aim for a target of 5.5 to 6.5. If you see intake drop, reassess the diet immediately.

10. Commit to a monthly program review

“Collaboration is the key to success,” Connelly says. A program that worked six months ago may need a tune-up today.

The Action: Meet monthly with your veterinarian and nutritionist to review fresh cow disease data, milk fever cases and blood calcium trends. Small, data-driven adjustments prevent major wrecks.

Watch the latest episode of The Bovine Vet Podcast focusing on milk fever here:

Zeolite Strategies Reshape Milk Fever Management on Dairy Farms

Thu, 09 Apr 2026 14:13:40 GMT

Milk fever remains one of the most well-known metabolic diseases in dairy cattle, yet it is far from solved. While clinical cases still occur on most farms, the larger — and often more costly — challenge lies beneath the surface: subclinical hypocalcemia.

That’s why transition cow management continues to be a critical focus for veterinarians and producers alike.

“If you have transition cow issues, you’re going to have metabolic issues. Cows aren’t going to come in and perform the way you think they should. You’re going to have repro issues. You’re going to see a whole host of effects,” Meghan Connelly says, research and technical director at Protekta and guest on the most recent episode of “The Bovine Vet Podcast” .

Against that backdrop, a growing number of nutritionists and veterinarians are turning to zeolite-based pre-fresh diets, a relatively new approach that is reshaping how the industry manages calcium metabolism during the transition period.

The Hidden Burden of Hypocalcemia in Dairy Cows

On most dairies, clinical milk fever rates fall between 1% and 5%, depending on herd management and nutrition strategies. Subclinical hypocalcemia, however, is far more prevalent, affecting an estimated 25% to 45% of cows in many herds.

Unlike clinical cases, subclinical hypocalcemia is difficult to detect — but no less important.

“Subclinical is where we can’t see it, but it’s happening. The cow has low blood calcium, but we can’t tell that she’s low. But that still has consequences for the cow. There’s all these different systems and calcium is such a critical mineral for all those systems. So many different diseases that are influenced by calcium status,” Connelly says.

Instead of obvious signs, these cows often present as subtle inefficiencies that compound over time. Reduced rumination, lower feed intake and increased rates of retained placenta, metritis and mastitis are all commonly linked to inadequate calcium status. These hidden cases can quietly erode both performance and profitability.

DCAD Diets: The Traditional Approach to Milk Fever Prevention

For decades, the primary strategy for preventing milk fever has been the negative DCAD (dietary cation-anion difference) diet, which works by inducing a mild metabolic acidosis that improves the cow’s responsiveness to parathyroid hormone (PTH).

“We feed different feed supplements that contain anions in order to drop urine pH. When urine pH drops, the system is primed for PTH to work and mobilize bone and help support calcium homeostasis when the cow calves,” Connelly says.

This approach is well validated and remains a cornerstone of transition cow nutrition. However, it comes with practical constraints that can limit its use, particularly in larger or more complex feeding systems.

Where DCAD can create friction:

Requires consistent access to low-potassium forages
Can reduce dry matter intake due to metabolic acidification
Depends on monitoring tools such as urine pH
Often still requires post-calving calcium supplementation

As operations scale and feed variability increases, these limitations have driven interest in alternative strategies that can deliver similar or improved outcomes with fewer constraints.

(Meghan Connelly)

How Zeolite Works: A New Strategy for Hypocalcemia Management

Zeolite offers a fundamentally different approach to milk fever prevention, one that targets phosphorus rather than acid-base balance.

“When we feed a zeolite diet pre-fresh, we bind dietary phosphorus. The cow goes, ‘Oh, I better go get more phosphorus.’ The main storage for phosphorus is in the bone. When she mobilizes bone, she brings double the amount of calcium with it,” Connelly says, referencing the P:Ca ratio in bone.

By binding dietary phosphorus in the gastrointestinal tract, zeolite creates a mild, controlled drop in blood phosphorus. The cow responds by mobilizing bone reserves to restore balance. Because bone contains both phosphorus and calcium in a fixed ratio, this process results in a simultaneous release of calcium into circulation.

Unlike DCAD diets, which rely on parathyroid hormone sensitivity, zeolite operates through a separate pathway involving fibroblast growth factor-23, a hormone produced in bone cells that acts on the kidneys to regulate phosphate levels, and vitamin D metabolism. The outcome — improved calcium availability at calving — is similar, but the biological mechanism is distinct.

Why Zeolite Adoption Is Increasing on Dairy Farms

Although zeolite has only been available in the U.S. since 2017, adoption has accelerated rapidly, according to Connelly. Much of that momentum is driven by a combination of visible on-farm results and meaningful management advantages.

Producers implementing zeolite programs often report improved calcium status through the first 48 to 72 hours after calving, along with fewer clinical milk fever cases.

“If you go from having 30 down cows a month to four, that’s a pretty big change,” Connelly says, referencing the improvement she has seen on farms changing to zeolite.

Beyond clinical outcomes, zeolite introduces greater flexibility into ration formulation. Because it does not depend on lowering dietary potassium, producers can incorporate a wider range of forages — including haylage, rye and sorghum — that would typically be restricted in DCAD programs. This allows better use of homegrown feeds and can reduce reliance on purchased inputs.

Zeolite programs are also associated with reduced dependence on calcium supplementation after calving. With cows already mobilizing calcium effectively, the need for boluses and intravenous treatments often declines, lowering both labor and treatment costs.

Management simplicity is another advantage. Zeolite eliminates the need for urine pH monitoring and reduces the number of adjustments required in close-up groups. In addition, because it does not induce metabolic acidosis, it avoids the intake suppression sometimes observed with DCAD diets, helping support dry matter intake during a critical window.

Where Zeolite May Not Be the Best Fit

Despite its advantages, zeolite is not universally applicable. Its effectiveness depends heavily on overall diet composition, particularly phosphorus levels.

Situations where DCAD may still be the better fit:

Diets high in phosphorus (e.g., distillers grains, canola meal)
Operations with well-optimized DCAD programs already in place
Systems where tight ration control supports consistent acidification

In high-phosphorus diets, zeolite may become saturated, allowing the absorption of the remaining free phosphorus, reducing its effectiveness and making DCAD the more reliable strategy.

A Technology Still Evolving and the Veterinarian’s Role

Compared to DCAD, which has decades of supporting research, zeolite remains a relatively new tool. Since its introduction in 2017, both research and field experience have rapidly expanded understanding of how best to implement it.

“We didn’t necessarily know everything about it when it came out. I like to say that we continue to learn in real time with this strategy,” Connelly says.

Advances in feeding guidelines, monitoring approaches and troubleshooting frameworks have already improved consistency across farms, and further refinement is expected as adoption continues.

As that evolution continues, veterinarians are playing an increasingly central role. Transition cow programs are becoming more nuanced, and selecting the right strategy requires more than simply choosing between DCAD and zeolite. It involves identifying herd-level challenges, interpreting blood calcium data and aligning protocols with nutrition and management realities on each operation.

Close collaboration between veterinarians, nutritionists and producers remains essential. No single approach fits every farm, and the most successful programs are those tailored to available feed resources, labor capacity and herd goals.

Zeolite is not a replacement for DCAD, it is an expansion of the milk fever management toolbox.

It represents a shift from priming calcium regulation through acidification to directly driving mineral mobilization through phosphorus control. For many dairies, that shift is delivering higher blood calcium, fewer clinical cases and simpler management during one of the most critical periods in the production cycle.

As the industry continues to refine its use, zeolite is quickly moving from a novel concept to a practical, field-proven strategy in transition cow nutrition.

To hear more from Connelly on using zeolite for the management of transition cows to avoid hypocalcemia, listen to the full conversation on the latest episode of “The Bovine Vet Podcast.”

Rethinking Milk Fever in Dairy Cows: How the Immune System Impacts Calcium Levels

Tue, 07 Apr 2026 19:50:26 GMT

Milk fever has long been framed as a calcium problem. But what if that framing is too narrow and part of the reason prevention strategies don’t always deliver consistent results?

Work from Burim Ametaj , Professor at the University of Alberta and recent guest on “The Bovine Vet Podcast” , is helping reframe hypocalcemia through what he terms the calci-inflammatory network — a model that links calcium dynamics directly to immune function during the transition period.

A Common Problem, Often Hidden

Milk fever remains one of the most widespread metabolic disorders in dairy cattle, but much of its impact is hidden in subclinical cases.

“Milk fever is widespread, but now we have this subclinical part of milk fever that is not visible. You need to get a blood sample to measure calcium to determine, based on the concentration of calcium in blood, whether the cow is going through subclinical milk fever or clinical milk fever,” Ametaj says.

These subclinical cases lack obvious signs, yet they are consistently linked to reduced intake, impaired immune function and increased risk of diseases such as mastitis , metritis and ketosis.

Despite decades of focus on calcium supplementation and DCAD strategies, hypocalcemia remains prevalent. This has prompted a closer look at the underlying biology.

(Farm Journal)

Total Versus Ionized Calcium: A Critical Distinction

A key refinement in this emerging framework is the distinction between total calcium and ionized calcium. While total calcium is commonly measured, much of it is bound to proteins like albumin or other molecules. Only a fraction exists as ionized calcium — the biologically active form required for muscle contraction, nerve signaling and immune cell function.

This distinction has important implications for treatment. While calcium borogluconate is a known treatment for hypocalcemia in cattle, Ametaj suggests it may not be ideal for ionized calcium availability.

“What happens?” asks Ametaj about blood ionized calcium levels when an animal receives calcium borogluconate. “It is decreased, in fact. In 1985 , there was a scientist who injected sheep with calcium borogluconate. He reported that ionized calcium decreased.”

Calcium therapy can improve clinical signs, particularly in recumbent cows, but it may not consistently restore the functional calcium pool. This helps explain why some cows respond only temporarily or relapse after treatment.

A Shift in Thinking: Hypocalcemia as Part of Immunity

Ametaj’s work proposes a fundamental shift in how hypocalcemia is interpreted — not simply as a failure of calcium supply, but as part of a broader physiological response.

“Hypocalcemia is important, because it’s not a deficiency, but part of immunity,” Ametaj says. “That’s where the entire new concept starts.”

In this model, calcium dynamics are closely tied to immune activity, particularly during the stress of calving and early lactation.

This model builds on another important shift: transition cows are not immunosuppressed, but are actively responding to inflammatory signals.

“Usually, the dogma is that the cows around calving are immunosuppressed, but in fact, they are mounting an immune response, especially the innate immunity is very active and acute phase response,” Ametaj explains.

Inflammatory markers begin to rise weeks before calving and peak around parturition. Cytokines such as TNF-alpha, interleukin-1 and interleukin-6, along with acute phase proteins, are consistently elevated during this period. Rather than a failure of immunity, this suggests the cow is managing a significant inflammatory load at the same time she is adapting metabolically to lactation.

In the framework of the calci-inflammatory network, bacterial endotoxins from conditions like mastitis or acidosis trigger an inflammatory response that suppresses parathyroid hormone secretion. This cascade ultimately inhibits calcium absorption and bone resorption, leading to hypocalcemia, commonly known as milk fever in cattle.

(Farm Journal)

Endotoxin: A Likely Trigger

One of the proposed drivers of this inflammation is endotoxin, or lipopolysaccharide (LPS), originating from the gastrointestinal tract.

Transition diets high in fermentable carbohydrates can lower rumen pH, disrupt epithelial integrity and increase endotoxin release and absorption. As rumen conditions become more acidic, Gram-negative bacteria break down and release LPS into the rumen environment.

“When you feed different amounts of grain, you increase the amount of endotoxin in the rumen fluid by 18- to 20-fold,” Ametaj says, noting these shifts were also seen in the blood along with changes in cytokines and acute phase proteins.

Once endotoxin enters circulation, it contributes to systemic inflammation, linking nutritional management directly to immune activation. The immune system responds rapidly to endotoxin exposure by activating macrophages and triggering signaling pathways designed to neutralize and remove the threat.

“If macrophages are activated, they release pro-inflammatory cytokines: tumor necrosis factor alpha, interleukin-1, interleukin-6. Why do they do that? Because they invite more cells, immune cells, to come there to remove endotoxin,” Ametaj explains.

This response is essential, but also metabolically demanding. Nutrients and minerals are redirected to support immune function, and physiology shifts to prioritize survival over production.

Calcium as an Active Player in Immunity

Within this framework, calcium is not simply a nutrient to maintain but an active participant in immune function.

One key role is in endotoxin handling. Lipopolysaccharide carries a strong negative charge, allowing calcium to bind and promote aggregation. This clustering makes endotoxin easier for immune cells to recognize and remove.

“Endotoxin is very negatively charged. And calcium binds to molecules of endotoxin and brings them together and creates aggregates,” Ametaj explains.

Endotoxin can also bind to lipoproteins in circulation and be transported to the liver, where it is neutralized and excreted in bile. This process is rapid and tightly regulated, linking inflammatory load to liver function and lipid metabolism.

Together, these pathways suggest calcium is being actively used and redistributed during immune responses, not simply depleted.

Current Strategies

Current approaches to milk fever focus on increasing calcium availability, either through supplementation or dietary strategies, such as DCAD. These tools remain valuable, but they operate within a more complex biological system than previously appreciated.

“By triggering metabolic acidosis, you also trigger elimination of calcium from the blood through urine outside. Why? Because calcium and other cationic ions bind these acids, and they are eliminated,” Ametaj says.

DCAD programs improve calcium mobilization, but they also shift systemic mineral balance. Similarly, calcium therapy can resolve clinical signs without addressing the underlying drivers of inflammation. This may help explain why these strategies work well in some situations but inconsistently in others.

What This Means for Veterinarians and Producers

This evolving perspective does not replace current practices, but it does broaden the approach to prevention.

In addition to managing calcium, attention may need to shift toward upstream factors that influence both inflammation and mineral balance, including:

Maintaining rumen stability and avoiding sharp drops in pH
Managing starch levels and fermentation rates
Supporting gut barrier integrity
Reducing systemic inflammatory load

These areas may offer opportunities to improve consistency in transition cow outcomes.

The immune–calcium network offers a more integrated way to understand milk fever — one that connects metabolism, inflammation and mineral dynamics.

Rather than asking only how to raise calcium status, a more useful question may be: Why is calcium low in the first place?

Answering that question may be key to improving transition cow health and to making existing prevention strategies work more consistently.

To hear more from Ametaj on the immune-calcium network and the management of transition cows to avoid hypocalcemia, listen to the full conversation on the latest episode of “The Bovine Vet Podcast.”

Can Phytogenics Shield Your Herd from Acidosis and Heat Stress?

Wed, 18 Mar 2026 17:27:08 GMT

Heat stress is intensifying, subacute ruminal acidosis remains widespread and dairy producers are under increasing pressure to maintain performance while reducing reliance on medications. Many of these challenges share a common thread: the gut.

From microbial imbalance to compromised intestinal barrier function, disruptions in gut health can trigger inflammation, reduced production and poorer welfare outcomes. Herd health is increasingly approached through the lens of gut integrity and systemic inflammation, and interest in nutritional tools that support digestive stability is growing.

Nicole Reisinger, senior scientist with dsm-Firmenich Animal Health and Nutrition in Austria, studies how feed additives influence gut biology, biomarkers and animal health. In a recent conversation on the “ Dairy Podcast Show ”, she described emerging evidence that plant-derived compounds may help cows cope with physiological stress affecting the digestive tract. Phytogenic feed additives may support gut health by stabilizing rumen microbial populations, strengthening intestinal barrier function and reducing inflammatory responses.

What Are Phytogenic Feed Additives for Cattle?

Phytogenic feed additives are gaining attention as part of this shift toward preventative herd health. Derived from plants, they include essential oils, herbs, spices and plant extracts, often combined into blends designed to produce complementary biological effects.

Reisinger notes part of their appeal lies in the biological roles these compounds already play in nature.

“The nice thing is that they’re kind of designed by nature. Those compounds all have a purpose in nature, so it’s quite logical that they would also have an impact on animals,” Reisinger says.

Rather than relying on a single compound, many phytogenic products combine multiple ingredients designed to influence several physiological pathways.

“It might be that one substance is not enough. You need to combine them in the right way so that you really have the effect you are interested in,” she explains.

These combinations may influence microbial activity, inflammatory pathways and digestive processes simultaneously — an approach that may be useful when addressing multifactorial health challenges in cattle.

Can Phytogenic Feed Additives Improve Rumen Health During Acidosis?

Subacute ruminal acidosis (SARA) remains one of the most common nutritional disorders in high-producing dairy herds. While ration formulation and feed management remain central to prevention, a growing body of research is beginning to show how phytogenic blends may influence rumen function during acidosis challenges.

This includes controlled work from the University of Veterinary Medicine Vienna, where phytogenic blends containing compounds such as menthol, thymol and eugenol have been shown to improve rumen pH, stabilize fermentation patterns and reduce inflammatory markers during SARA challenges.

“For acidosis, there were quite a few positive effects we could see. It really started with feed intake and then also saliva production and buffering the rumen pH. We had an influence on the pH of the saliva, but then also on the microbiome, which is very essential,” Reisinger says.

What recent research suggests:

A recent meta-analysis of essential oils in ruminants found these compounds can shift fermentation pathways, reduce ammonia production and improve efficiency without compromising animal health.

These effects are consistent with observed changes in rumen stability and feed utilization during acidosis challenges, where microbial modulation appears to play a central role in maintaining digestive function.

How Does Heat Stress Affect Gut Health in Cattle?

Beyond rumen acidosis, heat stress presents another major physiological challenge for cattle, particularly as extreme temperatures become more frequent and severe.

Heat stress can affect the digestive system in several ways, including:

Reduced blood flow to the intestinal tract
Increased gut permeability (leaky gut)
Movement of endotoxins into circulation
Activation of systemic inflammatory responses

“Phytogenics are essential for this kind of challenge because they can really impact gut permeability. They can really help to strengthen the gut barrier, and this is one of the major things we see with heat stress,” Reisinger says.

What recent research suggests:

Phytogenic blends can improve feed efficiency and nutrient utilization in lactating dairy cows under summer conditions without negatively affecting milk yield, even when dry matter intake is reduced.

By helping maintain intestinal integrity, phytogenics may improve the animal’s ability to cope with environmental stress.

Where Do Phytogenic Feed Additives Fit in Herd Health Management?

Despite the potential benefits, feed additives alone cannot solve complex herd health problems.

“It’s always a combination of nutrition as well as management. We also need to be honest that it’s not the feed additive alone,” Reisinger says.

Sound ration formulation, transition cow management and environmental controls such as ventilation and cooling remain essential. Phytogenic additives may serve as another tool to help cows remain resilient when stressors arise.

What recent research suggests:

In grazing dairy cows , phytogenic blends can lead to improvements in rumen fermentation and milk production comparable to monensin, supporting their role as a viable alternative.

What Is the Future of Phytogenic Feed Additives in Cattle?

Interest in phytogenic feed additives continues to grow as the dairy industry looks for preventative approaches that support productivity and animal welfare.

“I think phytogenics are a good choice for the future, especially thinking about staying a bit more into the natural support,” Reisinger says. “Consumers are probably interested in us looking more into biological support than giving medication.”

Many of the dairy cow’s most significant health challenges begin in the digestive tract. Supporting gut stability may be central to helping cows remain healthy and resilient in the face of both nutritional and environmental stress.

Does Every Calf Need a Gallon of Colostrum? Not Necessarily

Fri, 27 Feb 2026 22:04:44 GMT

For years, feeding a gallon of colostrum shortly after birth has been considered the gold standard for calf care. It’s simple, easy to remember and straightforward to train employees to follow. But today’s calves don’t all look the same. With more variation in size, some researchers are asking whether the same volume makes sense for every newborn.

During a recent “Dairy Health Blackbelt” podcast, Dr. Sabine Mann, associate professor at Cornell University, revisited the research behind that long-standing recommendation.

“One of the questions I have gotten frequently is, why are we feeding all calves a gallon of colostrum?” she says. “It’s a pretty widespread management strategy in the U.S. And if you try to dig into the literature of why that came about, there’s actually not that much evidence that that is the best approach for every calf.”

She notes that for an average 85- to 90-pound calf, four liters is probably appropriate. But not every calf falls into that range. When birthweights vary, feeding the same volume across the board may not always match what each individual calf truly needs.

Putting the Gallon Rule to the Test

To take a closer look at the gallon recommendation, Dr. Mann and her team conducted a study on a commercial dairy in collaboration with researchers at the University of Guelph.

They began by pooling colostrum to keep quality consistent across calves. From each pool, four calves were assigned different feeding levels based on a percentage of their body weight.

“We made a big pool of colostrum, and then we assigned four calves to that pool, and one calf got 6% and one calf got 8% and one calf got 10% and one calf got 12% so that was our range, six to 12,” Mann explains.

Rather than giving every calf the same fixed volume, the team adjusted how much colostrum each calf received relative to its size.

The intent was not to create a complicated system requiring producers to weigh every calf and calculate exact doses.

“This is not meant for people to weigh each and every single one of the calves and then figure out the milliliters,” Mann says. “But it’s for us to understand, is there an effect on the calf’s ability to take up IgG into circulation. And if there is, how would we translate this into actionable recommendations on farm.”

Ultimately, the study focused on whether feeding different amounts based on body weight would influence how well calves absorb the antibodies they need early in life.

More Isn’t Always Better

The study looked at how different colostrum volumes (as a percent of body weight) affected IgG in the blood, absorption efficiency, stomach emptying and calf comfort. As expected, bigger feeds gave calves more total IgG

“We found that the more volume they got within a certain quality of colostrum, the more IgG they had in their blood, which makes sense, right? The more you give, the more you get,” Mann says.

But the benefit slowed at the highest volume, 12% of the calf’s body weight.

“There was a declining return on investment, so to say, with increasing volumes,” Mann says. “There was a steep increase from 6% to 8% to 10% of body weight, but only a very small improvement in blood IgG concentration at 12% of body weight.”

This happened because calves absorbed a smaller proportion of the IgG when fed very large amounts.

“The proportion of the IgG in colostrum that actually appears in the blood was declining, meaning that the more volume you put into them, the less proportion the calf can actually take up into that in that window of time.”

When calves get a large meal, their stomach empties more slowly, so less colostrum reaches the intestine while the gut is still “open” to IgG absorption.

“We wanted to see if different volumes affect how the stomach empties colostrum into the intestine, and timing matters because the gut is only open for IgG absorption for a limited period.”

She compared it humans overeating during a holiday meal.

“We do this around Thanksgiving and Christmas, and we sit there and our belly hurts, right? Our systems know to slow down the gastric output in those situations, and that’s the same that happens in calves.”

Calf Comfort and Behavior

Dr. Mann’s team also looked at calf behavior, since small calves fed four liters often appear bloated or uncomfortable.

“We were interested in this notion from the field, and we did observe that the more volume we fed, the more we saw behavior associated with colic, like kicking the abdomen,” she says.

While lying time wasn’t significantly affected, higher volumes tended to reduce relaxed resting.

“We didn’t find a statistical effect in lying time, but those calves fed higher volumes tended to lie less in a relaxed position, similar to us at Thanksgiving,” she joked.

The “Goldilocks” Approach

When it comes to determining how much colostrum a calf truly needs, Mann describes the “Goldilocks” approach as the best option.

“I think we’re getting back to a Goldilocks approach where you want to have enough, but you don’t have to give too much,” she says. “Just the right amount is most beneficial to the calf.”

Based on this research, around 10% of a calf’s body weight is a solid target for an initial feeding. That amount provides enough immunoglobulins to support immunity without overwhelming the stomach, and it can be adjusted for smaller or larger calves.

Mann adds that while colostrum is packed with nutrients, extra benefits might be better delivered through multiple feedings rather than one very large meal.

“The nutritive value of colostrum should not be underestimated, but we also have to keep in mind the comfort of the calf,” she says. “Maybe it’s better given in separate feedings. A lot of farms have gone to feeding second feedings or even third feedings of colostrum.”

Practical Takeaways

While colostrum is essential for newborn calf health, Mann emphasizes that the goal isn’t to hit a fixed volume, but to give calves the right start while keeping them comfortable. She provides the following tips to use on the farm:

1. Know your herd’s average birth weight. “A good first step is to know the average birth weight of calves in your herd, since that can vary,” Mann says. “Once you know that, you can adjust the colostrum volume to match your average calf.”

2. Use a couple of standard volumes rather than one fixed size, “Many herds now use two standard volumes, like three liters and four liters. That way, even without a scale, you can look at a calf and decide: this one won’t be over 85 pounds, so it gets the smaller amount,” she says.

3. Consider second or third colostrum feedings. “Instead of giving all the colostrum at once, it can help to split it into two or three feedings if your farm can manage it,” Mann says. “Many people see benefits from this, though we could always use a bit more research to confirm.”

Assessing the Off-Feed Dairy Cow

Thu, 26 Feb 2026 19:00:17 GMT

The Consultant diagnostic support system for veterinary medicine lists 363 differentials for the off-feed cow. That number is a reminder that appetite loss is common and rarely simple.

Jessica McArt, professor and department chair at the Cornell University College of Veterinary Medicine, recommends using a disciplined approach to determine the reason why a cow isn’t eating.

In many herds, rumination data provides the first clue. As McArt describes, “You can see this cow has been ruminating anywhere from 500-550 minutes a day, and then over the last 24 hours has dropped pretty dramatically down to 100 minutes. That’s a sure sign that something’s wrong with her rumen.”

This drop tells you that something has changed, but it doesn’t tell you why.

Perform a Thorough Physical Exam

Before treating the rumen, determine whether the rumen is the primary problem. This involves performing a complete physical examination.

“Our goal with this exam is to determine if being off feed is your primary sign,” McArt says. “So, she may otherwise look OK, but the rumen is not moving well. Or is it secondary to a different issue?”

A displaced abomasum, metritis, mastitis, lameness or systemic disease can all reduce intake. Appetite loss is often the consequence, not the cause. A physical exam is non-negotiable. Only once secondary causes are ruled out should you narrow your focus to primary gastrointestinal dysfunction.

Listen to the Rumen

When the rumen is the likely source of issue, spend time with it. McArt advises listening to rumen sounds for a whole minute.

“We want to hear somewhere between one to three contractions,” she says. “These rumens can be hypomotile, or they can be hypermotile where you kind of hear this rumbling the whole time, but they’re not good and strong rumen contractions.”

Hypomotile rumens lack strength and frequency, while hypermotile rumens may produce continuous low rumbling without effective mixing. Neither pattern supports efficient fermentation.

Palpate rumen fill and assess fiber mat integrity. On a rectal exam, look for diarrhea or undigested fiber that suggests fermentation breakdown. These findings will help confirm whether you’re dealing with primary rumen dysfunction.

Consider Stage of Production

“You need to check the stage of lactation and how much milk she’s making,” McArt says. “If you see a cow and she’s 450 days in milk and she’s been making 30-35 lb., you would be like, ‘Well, that seems about right in that pattern.’”

Contrast that with a fresh cow scenario: “If the cow is 13 days in milk and she was making a lot of milk a couple days before, something is obviously wrong with her,” McArt says.

The severity and urgency change with physiology. Earlier lactation cows have less margin for error.

Assess Hydration

Not every off-feed cow is dehydrated, but many are mildly so.

“These cows, some of them are going to be dehydrated, some of them are not. So, we can see variations in skin tent. They may have sunken eyes; they may not,” McArt says.

Skin tent, globe position and mucous membrane moisture can provide clues. Mild dehydration may respond to oral fluids, but more marked dehydration requires more aggressive correction.

Support the Rumen

It would be great to have an ideal drench formula, but McArt comes with bad news: “I will tell you, I did a lot of research, I read a lot of papers. And the answer is nobody knows.”

This doesn’t mean that composition is irrelevant. Calcium, magnesium, phosphorus and sodium all support rumen function. Pairing these minerals with an energy source, such as calcium propionate, can be beneficial to the cow. Notably, phosphorus is often absent from commercial products, but is very important for energy metabolism and rumen fermentation.

The temperature of the oral drench is also critical.

“If you take cold water out of your house and you pump it into that rumen, those bacteria are not going to be happy, and you’re probably going to make the situation worse until she heats that back up,” McArt notes.

Rumen microbes function within a narrow temperature range. Warm water protects fermentation.

Consider Transfaunation

When fermentation has stalled, transfaunation, the therapeutic transfer of rumen fluid, may help.

“It’s been shown that transfaunation can be effective when giving as little as one liter into a cow,” McArt says.

Small volumes can improve rumen function compared with water alone. For farms with an accessible donor cow, transfaunation is a practical adjunct.

Offer Hay

Do not overlook simple mechanical stimulation.

“Studies have shown that if you offer cows that have indigestion some sort of long-fiber hay, they prefer to eat it and recover quicker,” McArt says.

High-quality long-stem hay can help reestablish rumen mixing and stimulate cud chewing. For some cows, this is enough to restart the system.

Be Mindful of a Larger Issue

If off-feed cows start appearing frequently, the conversation needs to widen beyond individual treatment protocols. Recurrent rumen dysfunction may signal ration inconsistency, bunk management problems, feed sorting or mycotoxin pressure .

“If you see this a lot, this is a great place where we can get engaged on the herd level in addition to the cow level,” McArt advises.

The off-feed cow may be an early warning signal for a larger management issue.

Mycotoxin Risk Holds Steady in 2025

Mon, 23 Feb 2026 19:49:09 GMT

According to the dsm-firmenich World Mycotoxin Survey , which assessed the global mycotoxin threat, 86% of North American samples tested above the recommended threshold for at least one mycotoxin. While mycotoxin levels haven’t necessarily escalated from 2024 to 2025, there was a shift in the distribution, which has some implications for cattle and swine operations.

“The 2025 results show a continued mycotoxin challenge, with contamination rates rising for both aflatoxins and zearalenone and average levels increasing across all major mycotoxins,” said Ursula Hofstetter, head of mycotoxin risk management at dsm-firmenich, in a press release.

The Major Players

Mycotoxins are toxic metabolites produced by fungi, most commonly Fusarium, Aspergillus and Claviceps species. They develop in the field and can persist through harvest and storage. Weather stress, hybrid selection and storage management all influence which toxins dominate in a given year.

The primary mycotoxins shaping North American livestock risk in 2025 were:

Deoxynivalenol (DON)
A Type B trichothecene produced by Fusarium species. Commonly found in corn and wheat. Often referred to as ‘vomitoxin’.
Zearalenone (ZEN)
Also a Fusarium toxin. Structurally estrogenic and frequently present alongside DON in corn and small grains.
Fumonisins (FUM)
Produced by Fusarium verticillioides and related species. Predominantly found in corn.
Aflatoxins (AFLA)
Produced by Aspergillus species. More common in drought- or heat-stressed corn.
Ergot alkaloids (ERGOT)
Produced by Claviceps species. Typically associated with small grains.

These toxins rarely occur in isolation. Co-contamination often shapes the reality producers see on the farm.

What Changed from 2024 to 2025

The 2025 North American mycotoxin prevalence in raw materials compared to 2024 shows the following shifts:

DON: 74% → 76%
ZEN: 73% → 78%
FUM: 46% → 55%
AFLA: 15% → 17%
ERGOT: 44% → 9%

Trichothecenes remain deeply entrenched, with DON prevalence increasing slightly. Most of this increase is a result of an increase in wheat (73% → 93%). Meanwhile, fumonisins rose meaningfully and ergots dropped sharply.

Cattle: Rumen Function, Immune Resilience and Production Losses

Cattle historically are considered somewhat more resilient to mycotoxins than monogastrics, owing to partial ruminal detoxification. However, evidence increasingly shows persistent exposure to Fusarium toxins like DON, ZEN and FUM, especially in combination, can exert significant effects on digestion, immunity and metabolic health.

When looking at global finished feed samples for ruminants:

DON was prevalent in 69% of samples and above the risk threshold in 53% of samples.
ZEN was prevalent in 73% of samples and above the risk threshold in 33% of samples.
AFLA was present in 34% of samples and above the risk threshold in 29% of samples.

Studies have demonstrated short-term exposure to Fusarium toxins, including ZEN and FUM, affects fermentation patterns and the microbial community, which in turn can reduce fiber breakdown and volatile fatty acid production — key drivers of energy supply in cattle. Even modest disruptions to the rumen microbiota can reduce feed efficiency and gain over time.

The immune system is also affected by mycotoxins. The immunosuppressive effects of common mycotoxins in ruminants have been documented , including alterations in cytokine gene expression, immunoglobulin production and macrophage function.

Further, individual toxins like AFLA have well-established effects on liver function and general metabolism in cattle. Chronic AFLA exposure has been linked to reduced appetite, lower weight gains and elevated liver enzymes, indicating compromised hepatic function that can impact production and health resilience.

These findings indicate how cattle performance and disease resistance can be eroded by the mycotoxin patterns reported in the 2025 data. Persistent DON and ZEN exposure, combined with higher FUM presence, places additional load on rumen fermentation and immune competence, potentially contributing to subclinical production drift.

Swine: Immune Disruption, Gut Barrier Injury and Performance Drag

In swine, elevated prevalence of DON, ZEN and FUM can exert systemic effects on immune function, gut integrity and reproductive physiology at both clinical and subclinical levels.

When looking at global finished feed samples for swine:

DON was present in 85% of samples and above the risk threshold in 41% of samples.
ZEN was present in 79% of samples and above the risk threshold in 19% of samples.
FUM was present in 44% of samples and above the risk threshold in 8% of samples.

Research has shown DON and FUM alter the gut epithelial barrier, impair immune defenses and increase bacterial translocation from the gut, making pigs more susceptible to infections even when properly vaccinated. In the immune tissues themselves, DON exposure has been linked to changes in the gene expression of key antimicrobial and inflammatory regulators, implying a weakened ability to respond to disease challenge at the cellular level.

ZEN adds another layer of complexity. Beyond its well-known estrogenic effects (i.e., swelling of reproductive tissues and altered estrous cycles), ZEN has been shown to suppress antibody production in porcine immune cells, reducing levels of IgM, IgG and IgA. These immunoglobulins are important for protective vaccine responses. This explains why farms employing what should be effective vaccination programs still report breakthrough disease.

Collectively, these mechanisms mean widespread DON and ZEN exposure is a disease vulnerability issue. When the gut barrier is compromised and immune cell function is suppressed, pigs are less able to defend against respiratory pathogens, enteric bacteria and systemic infections alike, and their response to vaccination may be diminished.

Mycotoxin Co-Contamination Defines 2025

The defining feature of mycotoxins in 2025 is not a single toxin spike, but co-contamination. Feeds routinely contain multiple mycotoxins at once and their effects overlap, creating steady biological pressure.

The result is rarely dramatic toxicosis, but production drift is reflected in reduced gains, narrower reproductive margins, lowered health resilience and increased performance variability.

With persistent DON, rising ZEN and higher FUM prevalence in North America, ingredient-level vigilance and close monitoring of performance trends are important. The mycotoxin burden did not spike, but it did rearrange.

Can Young Calves Manage Distillers Grain?

Thu, 03 Jul 2025 19:00:00 GMT

Soybean meal is currently the nearly universal protein source for calf starter grain formulations in the U.S.

But if you could tame some of the wilier aspects of distillers grain, it too can pack a powerful protein punch. Dr. Billy Brown, Assistant Professor at Kansas State University specializing in dairy cattle nutrition, discussed that possibility on a recent episode of The Dairy Nutrition Blackbelt podcast.

“One of the fascinating aspects of the ethanol industry today is that they’re getting really aggressive about trying to add value to the co-products they’re producing,” Brown noted. “It’s not just a bi-product. They’re doing a great job of trying to add value to those products that could realistically do great things for us in the dairy industry.”

Brown and his colleague recently conducted a preweaned calf study evaluating a specialty distillers grain product called “ Protomax^TM , manufactured by ICM, Inc.

The researcher noted there has been very little published literature summarizing research utilizing distillers grain as a protein source in calf starters. He said the few studies that have been performed showed relatively poor performance for calves fed distillers grains, in terms of calf growth and average daily gain (ADG).

“The high fiber content of the corn bran in distillers grains is probably a little bit more difficult for those calves to digest in that early life period,” Brown stated.

But thanks to a fractionation process that removes the corn brand, Protomax is more easily digested by preweaned calves. And, unlike earlier renditions of distillers grain, this product is dried without the solubles and fiber fractions.

The result is a highly digestible, low-fiber feedstuff that rivals soybean meal in protein content at about 50% crude protein. Brown said the manufacturers are also enhancing the product by fermenting yeast bodies, condensing the products of fermentation, and adding them back into the finished high-protein distillers grain.

Brown and his colleagues recently conducted a study comparing a starter grain formulation containing the new product to traditional calf starter using soybean meal as the protein source.

“We kind of expected some negative results as a part of including this high-protein corn product in the diet,” shared Brown. “We actually saw the opposite. Calves on the high-protein corn product grew more, had greater average daily gain, and tended to have more dry-matter intake, but there was no evidence of difference in feed efficiency.”

Even more encouraging were the results of actual digestibility. “To our surprise, the calves on the high-protein corn product actually had greater apparent total tract digestibility and crude protein digestibility,” he shared.

Brown noted that, compared to previous studies of distillers grains in preweaned calf diets, the Kansas State researchers were mindful of amino acid balancing. They used the CNCPS model to meet estimated lysine and methionine requirements using rumen-protected supplements for those potentially limiting amino acids.

And the financial bottom line? Encouraging as well. The cost of the distillers grain-based ration was about $5.00/ton less than the traditional soybean meal-based ration. Even including the cost of the amino acid supplements, the net cost was about 6 cents/calf/day lower for the distillers ration.

While acknowledging this study is an initial foray into a whole new possibility for preweaned calf rations, Brown is encouraged by the results.

“We know that calves that gain more weight in the preweaning period have greater lifetime milk production,” he noted. “A lot of that comes from the milk feeding program, but if we can also help accomplish that with the grain feeding program – even carrying into the post-weaning period for a month or so – that’s a really positive benefit for that calf long-term down the road.”

Your Next Read: There are Many “Wheys” to Feed Dairy Cows

Biotics in Bovines: Postbiotic Applications for Dairy Cattle

Thu, 06 Nov 2025 20:03:00 GMT

Dairy cattle nutrition is increasingly being designed to shape the microbiome, not just to feed it. Postbiotics represent the third category in that effort. Rather than supplying live microbes (probiotics) or microbial substrates (prebiotics), postbiotics are the beneficial compounds microbes produce, without the organisms themselves.

This matters because high-producing dairy cows operate under tight metabolic margins. Transition stress, rapid shifts in energy demand, and rumen fermentation instability can all disrupt gut integrity and immune balance. Postbiotics offer a way to influence those systems even when microbial populations are stressed, inconsistent or slow to stabilize.

This is the fifth installment of the Biotics in Bovines series where we will explore the role and application of prebiotics, probiotics and postbiotics in dairy and beef cattle nutrition. Each installment will examine a different facet of microbiome-focused nutrition from how these products work to what recent research says about their effectiveness and on-farm value. The goal is to help veterinarians and producers make informed, evidence-based decisions about integrating biotic feed technologies into herd health and performance programs.

Postbiotics are non-living microbial products that interact with the rumen and immune systems. They commonly include:

Yeast Fermentation Products
Lactic Acid Bacteria Metabolites
Inactivated Bacteria

These compounds can be used to strengthen gut barrier integrity, support immune signaling, encourage resilience in fiber-fermenting microbes and reduce the impact of stress-related dysbiosis. Unlike probiotics, they do not require survival through pelleting, storage or rumen passage, which could be a practical advantage on the farm.

Evidence in Dairy Systems

In dairy calves , yeast fermentation products fed in the milk replacer had greater postweaning average daily gains and body weights with similar feed intake. These calves also had improved rumen absorption (observed as increased plasma volatile fatty acid concentrations) and increased immune response to lipopolysaccharide stimulation at weaning.

During the transition period , postbiotics containing yeast fermentation products have been shown to improve the lactation performance and metabolic status of dairy cows. This supplementation reduced inflammation and enhanced liver metabolic function resulting in greater milk fat and improved energy corrected milk yield.

One study in lactating dairy cattle investigated whether the incorporation of yeast fermentation products had any effect on the prevention and control of digital dermatitis. They found that postbiotic treatment decreased the risk of cattle having ulcerative and active lesions and slowed the negative progression of lesions.

In dairy cattle with mastitis , the administration of a heat-killed Lactococcus lactis postbiotic was as effective in eliciting a localized immune response as the administration of live L. lactis. Postbiotic treated cattle had an equally potent interleukin-8 response and cure rates based on somatic cell counts compared to probiotic treated cattle. These results could have beneficial implications for farmers worried about the shelf-life of live probiotics.

Practical On-Farm Guidance

Consider incorporating postbiotics into your milk replacer. Postbiotics can support healthy rumen and hind-gut development jump-starting calves for their postweaning lives.
Use postbiotics to strategically support the immune system. This includes stressful events such as heat stress events, group/pen changes and vaccination periods.
Check the label. Dose and duration guidelines vary by product and production stage.
Postbiotics are less susceptible to environmental conditions than probiotics. This might make them a better fit for your farm.

Limitations and Research Gaps

Postbiotics are relatively new to ruminant nutrition. Extensive research has not yet been completed and the most effective metabolite combinations may remain to be discovered. The long-term effects across multiple lactations remain uncertain; using postbiotics as precision tools rather than as blanket-use additives might be most beneficial.

Actionable Takeaways

Start where the risk is the highest. Prioritize young calves or transition cows where the research shows the clearest and most repeatable benefits.
Choose products with a clearly stated microbial source and processing method. ‘Fermentation product’ tells you very little about what you are feeding. Look for specific strain and process information.
Pair postbiotics with management, not instead of management. Foot baths, milking hygiene, feed access and bunk management still drive outcomes. Postbiotics can support these efforts, but they don’t replace them.
Reassess during quiet periods. Once stressors ease, evaluate whether continued supplementation still provides return on investment.

Your next reads:
Biotics in Bovines: Prebiotic Applications for Beef Cattle
Biotics in Bovines: Prebiotic Applications for Dairy Cattle
Biotics in Bovines: Probiotic Applications for Dairy Cattle
Biotis in Bovines: Probiotic Applications for Beef Cattle

Rethink the First Feeding: Calf Health Begins with Smarter Colostrum Strategies

Mon, 03 Nov 2025 15:16:06 GMT

For decades, dairy producers have fed newborn calves based on standard protocols for first-milking colostrum, but as Dr. Donald Sockett and Dr. Ryan Breuer from the University of Wisconsin noted on a recent Raising Your Best Dairy Heifer webinar, the underlying assumptions might be due for revision.

“The current colostrum feeding guidelines that are considered best practices today were developed a little more than two decades ago,” Breuer says. “So we’ve had some time to observe what’s going on with it and whether we need to make some changes or not.”

Sockett explains that the conventional gold standard of 50 grams of immunoglobulin G (IgG) per liter, which the guidelines are based on, was reasonable back then, but times have changed.

“The average here is 75 g to 95 g per liter,” he says. “Why would we build a program around fair [quality] colostrum?”

Because calves are receiving colostrum of higher quality than what the older guidelines are built around, feeding volumes and methods might need adjustment.

In a recent case report , Sockett and Breuer described a Holstein heifer that received what is considered best practice for colostrum delivery based on 10% body weight: 4 liters of first-milking colostrum 30 minutes after birth and an additional 2 liters six hours after the first feeding. Shortly after the second feeding, the calf developed colic and was in apparent pain. This animal was humanely euthanized less than 24 hours later after a lack of response to on-farm medical care.

According to the attending veterinarian, this was not a one-off case.

“This wasn’t the only calf at this dairy,” Breuer says. “The veterinarian had also seen similar situations at other dairies where these calves, after the recommended colostrum feeding, had distress or colic.”

Upon necropsy, they noticed incidents of aspiration in the lungs. It was concluded aspiration pneumonia killed the calf after some colostrum was regurgitated due to a distended abomasum from colostrum volume.

This report emphasizes the need to reevaluate colostrum feeding standards.

In September, Frederick and colleagues from Cornell University published a study looking into the effects of feeding colostrum at 6%, 8%, 10% or 12% of a calf’s body weight on IgG absorption, gastric emptying and postfeeding behavior.

Gastric emptying is an important factor as no colostrum absorption occurs in the abomasum. Passage to the small intestine in a timely manner before absorption efficiency goes down is key. Calves fed at 10% and 15% of their body weight had significantly lower apparent efficiency of absorption of IgG rates and showed significantly more behavioral signs of discomfort (abdomen kicks) than those fed 6% and 8%.

“So yes, you’re feeding a bigger mass of immunoglobulin when you feed these larger body weight [percentages], but if your efficiency of absorption is going down and you have these health complications, is that really the best thing for the calf?” Sockett says.

A study of 818 calves across 61 Holstein dairy farms by Morin and colleagues at the University of Montreal looked into how colostrum management practices impacted transfer of passive immunity (TPI). They found that the No. 1 factor affecting apparent IgG absorption was the concentration of IgG in the colostrum, or colostrum quality. Calves fed colostrum with a Brix value over 24.5% were almost three times more likely to have received adequate TPI. Additionally, calves fed equal to or greater than 2.5 liters of colostrum at their first meal (notably less than 10% of the calves body weight) within three hours of birth had the highest odds of receiving adequate TPI.

This adds weight to Sockett’s assertion.

“Think about our recommendation standards,” he says. “We haven’t even been talking about the two most important variables of effective efficiency of colostrum absorption. We have to start thinking about the quality of the colostrum and the mass of colostrum being delivered.”

If you’re creating a colostrum feeding program for a dairy operation, Sockett and Breuer recommend collecting a database of information of what’s going on in the herd. Answer the following questions to tailor the program to your farm:

What is the average birth weight of the calves? What are the lightest and heaviest animals?
Are you feeding pooled or individual colostrum?
What is the normal weight of the colostrum?
What is the mean and standard deviation of the Brix scores?
What is the timing of first colostrum delivery?
What are your TPI goals?

The idea is not to abandon colostrum best practices but to update them strategically. By refining colostrum feeding protocols, verifying colostrum quality, aligning volume with body weight and monitoring outcomes, dairy operations can create their own evidence-based practice. The result? Healthier calves, fewer complications and better use of that liquid gold.

Biotics in Bovines: Probiotic Applications for Dairy Cattle

Wed, 22 Oct 2025 15:23:30 GMT

As antibiotic stewardship and sustainability become central goals for the dairy sector, probiotics are gaining attention as a way to strengthen cattle health and performance. Probiotics are live microorganisms that confer a health benefit to the host. In dairy cattle, they can stabilize the rumen function, support immune balance, and improve growth and milk performance. Recent work has shown certain bacterial and yeast strains are a promising tool for application in dairy herds.

This is the third installment of the Biotics in Bovines series where we will explore the role and application of prebiotics, probiotics and postbiotics in dairy and beef cattle nutrition. Each installment will examine a different facet of microbiome-focused nutrition from how these products work to what recent research says about their effectiveness and on-farm value. The goal is to help veterinarians and producers make informed, evidence-based decisions about integrating biotic feed technologies into herd health and performance programs.

You can find links to the first installments at the end of this article.

Probiotics used in dairy cattle include a wide range of bacteria and yeasts, each with distinct mechanisms of action. Common groups include:

Lactic acid bacteria (Lactobacillus, Enterococcus, Bifidobacterium): Enhance intestinal barrier function and suppress pathogenic bacteria.
Bacillus species: Spore-forming bacteria that can reduce inflammatory responses.
Yeasts (Saccharomyces cerevisiae, Kluyveromyces marxianus): Improve rumen fermentation, fiber digestion and feed efficiency.

These organisms act by stabilizing the rumen and intestinal microbiome, enhancing volatile fatty acid (VFA) production, reducing lactic acid accumulation and strengthening mucosal immunity.

Evidence in Dairy Cattle

Calves and Heifers

A 2025 meta-analysis including 55 studies reported feeding probiotics to dairy calves might be beneficial for enhancing dry-matter intake (DMI), starter intake and average daily gain (ADG). However, results across studies were variable, as were the type of probiotic used. Supplementation with Bacillus spp. and Lactobacillus spp. was found to increase ADG, while Lactobacillus spp. increased starter intake.

Probiotic supplementation has also been used to mitigate calf diarrhea related to Clostridium perfringens. In a challenge study using colostrum-deprived dairy calves, daily feeding of Lactobacillus animalis and Propionibacterium freudenreichii before, during and after an oral challenge of C. perfringens significantly reduced the incidence and severity of diarrhea and improved survival compared to controls.

Lactating and Transition Cows

Both qualitative and quantitative improvements to milk production have been observed with probiotic supplementation. Lactating dairy cows fed S. cerevisiae had increased DMI and milk yield compared to controls. This yield increase was thought to be a consequence of an improved rumen environment (pH, VFA ratios). Yeast supplementation has also been shown to increase milk protein content via enhanced microbial crude protein.

Probiotics have also been shown to support cattle through the transition period when fat stores in the body are being mobilized. A probiotic blend including Bacillus spp. fed in the weeks surrounding calving has been shown to be beneficial for supporting liver function, while a yeast-bacteria mixture fed to transition cows increased DMI and milk fat percentage.

Intravaginal probiotics have also been investigated for transition cows. The application of a freeze-dried lactic acid bacteria culture before and after calving increase milk yield and feed efficiency, with a greater effect on multiparous cows compared to primiparous cows. Intravaginal probiotic application has also been shown to improve uterine involution postpartum, decrease incidence of uterine infection and increase conception rates at first insemination.

Practical On-Farm Guidance

Prioritize products with clear strain identification and dosage instructions. The type of probiotic you want to use will change depending on animal age and production stage.
Match product type to production phase.
- Calves: Use lactic acid bacteria in milk replacer or starter feeds to support early gut development and reduce scours.
- Transition cows: Target yeast- or Bacillus-based probiotics to improve rumen stability, feed intake and immune balance. Consider intravaginal applications for reproductive health.
- Lactating cows: Consider Bacillus or yeast strains to support fiber digestion.
Maintain consistent feeding and delivery. Probiotic organisms should be ingested daily to remain effective. Interruptions in feeding can negate benefits.
Monitor outcomes. If you don’t measure it, you can’t manage it. Track performance and health data so you know what is and isn’t working for your herd.

Limitations

While probiotics show broad potential, their efficacy depends heavily on strain, dose and management. The complexity of the rumen environment means that not all strains may be effective and every dose. Results are most reliable when using stage-specific, well-characterized strains with proven viability under farm conditions.

Actionable Takeaways

Start early for best results. Introduce probiotics in milk replacer during the first two weeks of life to reduce diarrhea risk and support rumen development.
Target the transition period. Feeding probiotics from three weeks precalving through 30 days in milk can help stabilize DMI, support liver function and improve reproductive performance.
Feed through stress events. During heat stress, transport or ration changes, probiotic supplementation can help maintain rumen pH stability and DMI.
Evaluate cost-benefit periodically. The economic return depends on herd health status and management; probiotics tend to be most profitable when used strategically.

Your next reads:
Biotics in Bovines: Prebiotic Applications for Beef Cattle
Biotics in Bovines: Prebiotic Applications for Dairy Cattle

Biotics in Bovines: Prebiotic Applications for Dairy Cattle

Fri, 10 Oct 2025 01:37:29 GMT

Dairy industry professionals are increasingly turning attention to the gut microbiome as a tool to reduce disease, improve growth and protect herd productivity without relying on routine antibiotics. Prebiotics — non-digestible feed substrates that selectively feed beneficial microbes — are one practical, low-risk option.

This article kicks off a series where we will explore the role and application of prebiotics, probiotics and postbiotics in dairy and beef cattle nutrition. Each installment will examine a different facet of microbiome-focused nutrition from how these products work to what recent research says about their effectiveness and on-farm value. The goal is to help veterinarians and producers make informed, evidence-based decisions about integrating biotic feed technologies into herd health and performance programs.

The most common prebiotics supplemented to dairy cattle include:

Fructooligosaccharides
Mannanoligosaccharides
Galactooligosaccharides
Inulin
Beta-glucans

These are commonly sourced from yeast cell walls, yeast culture and agro-industrial wastes. While the main goal of prebiotic use is to provide substrate for beneficial gut bacteria, they can also modulate immune response and bind to harmful pathogens. Prebiotics fermented by select gut microbes can lead to the production of short-chain fatty acids, gut pH lowering (which inhibits harmful bacteria), enhanced gut barrier function and immune modulation.

In dairy cattle, the primary goals of prebiotic use are enhanced milk production and quality, to support gut health and immunity (especially high-stress periods), and to improve nutrient absorption. Calves have been shown to respond well to prebiotic supplementation, while results in adult cows are more varied.

Recent calf trials report the clearest, most consistent benefits.

Fructo-oligosaccharide (FOS) supplementation during the nursing period has been shown to support hindgut maturation, increase persistence of beneficial Bifidobacterium, and improve average daily gain in newborn dairy calves. These outcomes make FOS attractive for calf rearing protocols aimed at reducing diarrhea and improving early growth.

Mannan-oligosaccharides (MOS) and inulin have a similarly strong calf focused-evidence base. Experimental work indicates MOS can improve average daily gain and reduce pathogenic Escherichia coli in the feces. In a calf study investigating the effects of inulin supplementation, increased physical rumen development was observed in 3-week-old calves fed for two months.

Trials in adult lactating cows show inconsistent production responses. Some studies have suggested that inulin supplementation can increase milk production, possibly through upregulated rumen volatile fatty acid concentrations , and enhance antioxidant and immune function. Meanwhile, MOS supplementation has been shown to decrease the populations of harmful fungi in the rumen.

Overall, more variable responses should be expected in adult cows because the mature rumen ecosystem buffers dietary changes, reducing the impact of prebiotics.

Practical, On-Farm Guidance

Choose the right target and the right product. Prioritize prebiotics for calves for diarrhea reduction, average daily gain improvement and gut maturation, where evidence is the strongest. For adult cows, focus on well-documented products or use prebiotics as a part of a combined synbiotic strategy.
Match form and timing to the goal. For calves, FOS or MOS in milk replacer is practical and supported by trials. For dry or fresh cows, consider top dressing or inclusion in the TMR for specific use cases.
Start with a controlled trial. Test a product in a defined pen or cohort. Track clear outcomes: fecal scores, average daily gain, time to weaning, medicine use, and for cows somatic cell count, milk yield, and disease treatments. Compare the cost versus the value of reduced disease treatments and labor.
Watch interactions and quality. Prebiotic effects vary with dose, base diet and other additives. Use products with transparent specifications and consult existing trial data.

Limitations and Research Gaps

Ruminant probiotic research is growing, but not uniform: neonates and young calves respond more reliably than adult cows, and product heterogeneity makes generalizations risky. Large on-farm replication trials, and longer-term studies on lifetime productivity and economics are still needed to fully understand the impact prebiotics can have on adult dairy cow performance.

Actionable Takeaways

Use prebiotics first in calf programs where diarrhea and average daily gain are priorities.
Run a small, controlled on-farm trial with clear metrics to determine what works for you.
For lactating cows, use prebiotics as part of multi-modal strategies and set conservative return on investment expectations.

The Impact of Low Trace Minerals in Cattle May Be Bigger Than You Expect

Wed, 08 Oct 2025 17:12:13 GMT

Trace minerals — including copper, selenium, zinc, manganese and cobalt — are needed in vanishingly small amounts. However, when these nutrients fall even the smallest bit short of a cow’s needs, the consequences can be significant. These results can include slower growth, compromised immunity and poor reproduction.

Although trace minerals make up less than 0.01% of an animal’s body weight, they’re fundamental co-factors in enzymes, antioxidants, metabolic and immune pathways. Subclinical deficiencies may be a more extensive problem as the symptoms are not evident and there is no intervention, leading to economic losses.

David Schaeffer, professor at the University of Illinois, and his colleagues recently published work analyzing trace mineral concentrations from beef and dairy livers submitted to the California Animal Health & Food Safety Lab System laboratory between 2012 and 2021. The aim of this work was to compare any correlation patterns of copper, selenium, and manganese contents, and incidence of disease.

This work included 1,495 liver samples collected from cattle submitted for diagnostic testing. They were categorized as beef (857) or dairy (638), and further grouped by age (neonates, adolescents and adults).

The study revealed significant differences between deficiencies in beef and cattle. Overall, 73% of beef cattle and 45% of dairy cattle were found to be deficient in at least one trace mineral. In beef cattle, 46% of cattle were deficient in selenium, while 39% were deficient in manganese and 33% were deficient in copper. In dairy cattle, 10% of cattle were deficient in selenium, while 37% were deficient in manganese, and only 5% were deficient in copper.

(Adapted from Schaeffer et al., 2025)

The observed increased incidence of deficiency in beef cattle is likely expected as these animals often rely on free choice minerals, while dairy cattle are fed a total mixed ration including a mineral supplement. Interestingly, Schaeffer also reported a large portion of dairy cattle may have been oversupplemented as they observed above normal copper and selenium levels.

Associations between mineral status and disease occurred across both groups, but were most prevalent in beef cattle.

In beef cattle reported to have bovine respiratory disease (BRD), 68% of animals were deficient in copper, selenium or both minerals. The median age of these animals was 8 months, and most of them had been recently transported and co-mingled with other calves.

One thing the authors noticed was some conditions that are usually subclinical in beef cattle, for example parasites, were fatal in animals that were deficient in copper, selenium, or both.

“Now obviously we don’t know the condition score of those animals,” says co-author David Villar on a recent episode of “Have You Herd?”. “I would imagine it was pretty poor to die from internal parasites.”

As stated above, dairy cattle cases had much lower prevalences of trace mineral deficiency. Along with this, they also had lower incidences of correlation between deficiency and disease.

Of the dairy cattle with only one deficiency, the most frequent diagnoses were BRD (23%), Salmonella (14%), scours (16%), and septicemia (6%). Of all dairy cattle, 11% of those with BRD also had a copper or selenium deficiency.

It’s important to remember these are correlations between mineral status and disease, not causation.

Villar highlights what he hopes producers and veterinarians would take away from this work: “The main conclusion I would make is that beef, but not dairy, are still largely deficient in essential microminerals, copper and selenium. We need to check the herd management to see what’s happening.”

These results present an opportunity for producers and veterinarians to build preventative mineral nutrition programs, especially in beef herds where deficiencies are more prevalent. Proactive monitoring and targeted supplementation could reduce disease, mortality and economic loss in cattle herds.

Ketosis in Dairy Cows: Strategies for Prevention and Management

Fri, 26 Sep 2025 11:43:21 GMT

Ketosis continues to be a metabolic disorder that impacts dairy cows from precalving to 100 days after calving. The basics of ketosis is when dairy cows go into a negative energy balance, leading to the mobilization body fat (reserves) to meet the demand for energy associated with high milk production, late pregnancy, high milk fat content related to mobilized body fat (non-esterified fatty acids or NEFA) and limited dry matter intake.

Blood glucose demand is high due to synthesis of milk lactose (sugar), immune system demands due to calving stress and insulin resistance. If excessive NEFA are mobilized, the liver can convert NEFA to blood ketones. Blood ketones can be used as an energy source, but excess levels can be excreted in milk as ketones (lost energy), reduced dry matter intake and lower milk production.

Wisconsin DHI data reflect the potential costs and risks with ketosis. In a field study, 3,400 herds and 215,000 cows over three years were evaluated using milk ketone analysis from day five to day 21 after calving. First lactation cows that had ketosis had a 22% chance for ketosis in the next lactation. Older cows had a 45% chance of developing ketosis in the next lactation if they had ketosis in the current lactation. Milk ketone tests are available in U.S. and Canadian DHI labs.

Cows may have elevated ketones and NEFA in the first week after calving. The challenge can cause cows to shift their metabolize in week two, based on Minnesota data. Nutritional and management factors can be considered on dairy farms.

Body Condition Score
Research results show excessively heavy cows have lower dry matter intake after calving and mobilize excessive body weight. For optimal health and production, the body condition scores for dry cows should be 3.0 to 3.25 (score ranges from 1 as thin to 5 as excessively fat.) It’s suggested for heifers to calve at a BCS 3.0.

The problem can start on farms before cows enter the dry cow pen due to lower milk production, delayed pregnancy, health issues and one TMR being fed to all lactating cows.

Wisconsin researchers reported cows at 150 days pregnant were fed a high group TMR or switched to a lower energy ration prior to drying the cows off. The low energy diet contained 0.68 Mcal per pound of dry matter, 20% starch, and 4.3% fat. The high energy diet contained 0.79 Mcal per pound of dry matter, 29% starch, and 5.6% fat. All cows were fed the same lactating ration after calving. The high energy group had a BCS of 3.69 and 44 millimeters (mm) of back fat. The low energy group had a BCS of 3.25 and 37 mm of back fat. The low energy group had higher dry matter intake 10 days before calving and 21 days after calving. No significant differences in milk yield were reported between groups (the low group averaged 73 pounds compared to 78 pounds in the high group in the initial 21 days after calving).

NEFA blood levels were lower for the lower energy group, with lower incidences of retained planta, metritis and displaced abomasum (66 cows in the study did not allow for statistical differences.) Less propylene glycol treats were reported in the low energy group (4 treatments compared to 13 for the high energy group). Cows in late lactation should be evaluated for BCS to determine if a lower energy group is needed. One guideline is 10% to 15% of a herd could be moved to a low energy diet.

Dry Matter Intake
If dairy cows can achieve higher dry matter intake after calving, this can solve the problem of meeting energy needs while reducing the amount of body weight loss. Key factors include having close-up and fresh cow diets to smoothly transition diets meeting the nutrient needs of the cow and unborn calves along with colostrum synthesis. Pay attention to forage quality (keeping uNDF under 10% of the ration dry matter), avoid overcrowding (under 100% bed and feed bunk capacity in close-up and fresh cow groups) and separate heifer groups (social interaction and different feed consumption patterns).

Feed Additives
Feed additives can impact energy dynamics in dairy cows. Feeding rumen-protected choline during the transition period can increase dry matter intake after calving while reducing fat accumulation in the liver, along with greater milk yield for the entire lactation. Monensin can increase the level of propionic acid, a rumen volatile fatty acid, and provide a source of blood glucose.

Chromium can improve insulin and glucose responses (0.5 ppm in the ration dry matter). Propylene glycol drenched at 300 to 500 milliliters per treatment can increase blood glucose levels leading to an insulin response. Continue drenching until milk or blood levels of ketones drop.

Feeding propylene glycol does not lead to the surge in blood glucose. Yeast products and buffers can stabilize the rumen pH, fiber digestion and improve microbial production of VFA and amino acids.

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Feed Efficiency: A Basic Metric for a Complex System

Fri, 19 Sep 2025 14:14:27 GMT

Feed efficiency has become a growing topic in the dairy industry, driven by sustainability goals and desires to optimize farm profit. But what is feed efficiency, how can it be influenced, and should you use the measure on your farm?

What is Feed Efficiency?
At its core, feed efficiency asks how well do cows utilize the feed that is provided. There are many ways to define feed efficiency depending on context, whether in research, genetic evaluation or farm management. The most common measure on dairy farms is pounds of energy corrected milk (ECM) divided by pounds of dry-matter intake (DMI). Throughout this article series, feed efficiency will refer to this metric (ECM/DMI), which gives a snapshot of how effectively a cow turns feed into milk.

Feed efficiency values typically range from 1.3 to 1.8 depending on stage of lactation, milk production level, cow health and other factors¹. Low feed efficiency might indicate a cow is not converting feed into milk efficiently, possibly due to poor digestion, health issues or other competing biological demands. On the flip side, extremely high feed efficiency could signal that a cow is mobilizing too much energy from body reserves (fat) to support milk production, which is not sustainable long-term.

Limitations of Feed Efficiency (ECM/DMI)
While improving feed efficiency could help reduce costs or improve resource use, it’s important to recognize ECM/DMI has limitations.

Feed efficiency reflects just a snapshot of performance and is influenced by many variables: stage of lactation, animal health, feed quality, ration formulation, bunk management, environmental conditions, stress and more^2,3. Feed efficiency calculated as ECM/DMI can be misleading, especially if cows are gaining or losing body condition. In those cases, the metric could over- or underestimate true efficiency. Additionally, feed efficiency doesn’t account for feed intake or growth during the dry period or heifer-rearing stages because it focuses only on lactating cows. Therefore, ECM/DMI alone cannot tell the whole story.

Feed efficiency does not directly reflect economic efficiency⁴. A higher ECM/DMI ratio doesn’t always mean better profit, especially if increased feed costs or shifts in component production offset gains. Similarly, cows, groups or herds with the same feed efficiency can still differ in economic return. For example, in Table 1, both cows have identical feed efficiency, but Cow B generates more milk and more income over feed cost (IOFC) than Cow A. This is because, in this case, each additional pound of milk adds more revenue than the cost of the extra dry matter, assuming feed costs per pound of dry matter remain constant.

Identical feed efficiency doesn’t mean equal profit. Example assumes 4.3% fat, 3.2% protein, milk pricing based on Federal Milk Marketing Order 30 at the time of writing, and feed cost of $0.15/lb of dry matter.

(UW-Madison Division of Extension)

Feed Efficiency: Neat to Know or Need to Know?
Feed efficiency can be an interesting (neat to know) number on your farm, but its value expands when it becomes part of your decision making (need to know).

In the neat to know stage, you might collect and review the data out of curiosity. When feed efficiency becomes need to know, it’s because you’re actively using it to guide management decisions such as adjusting rations, targeting forage use or tweaking cow management strategies. When paired with other farm metrics, feed efficiency can be a valuable, although imperfect, tool for tracking progress toward goals. Accurate feed efficiency data depends on reliable measures of DMI, milk yield and milk components. Errors in estimating intakes or milk production can distort this calculation.

Building from the Basics
Feed efficiency is a basic metric that provides a basic overview of how well your cows convert feed into milk. While it’s not a perfect measure of efficiency and doesn’t capture the full complexity of dairy farm efficiency, it offers a starting point for evaluation.

In future articles, we’ll explore the web of factors that impact ECM/DMI, management strategies to influence feed efficiency, and how to create a data action plan to support your farm’s success.

References:

Hutjens, M. (2013). Hoard’s Dairyman webinar: Feed efficiency – what’s new? [Webinar]. Hoard’s Dairyman. https://hoards.com/videos-54-hoards-dairyman-webinar-feed-efficiency&mdashwhats-new.html
Phuong, H.N., Friggens, N.C., de Boer, I.J.M, & Schmidely, P. (2013). Factors affecting energy and nitrogen efficiency of dairy cows: A meta-analysis. Journal of Dairy Science, 96:7245-7259. http://dx.doi.org/10.3168/jds.2013-6977
VandeHaar, M.J., Armentano, L.E., Weigel, K., Spurlock, D.M., Tempelman, R.J., & Veerkamp, R. (2015). Harnessing the genetics of the modern dairy cow to continue improvements in feed efficiency. Journal of Dairy Science, 99:4941-4954. http://dx.doi.org/10.3168/jds.2015-10352
de Ondarza, M.B. & Tricarico, J.M. (2017). Review: Advantages and limitations of dairy efficiency measures and the effects of nutrition and feeding management interventions. The Professional Animal Scientist, 33:393-400. https://doi.org/10.15232/pas.2017-01624

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Can We Feed Dams for Better Performing Calves?

Thu, 11 Sep 2025 11:45:57 GMT

In the delicate dance that is dairy nutrition, it’s not all about just getting more milk.

How and what we feed pregnant cows also matters for the development of the calf she is carrying. Researchers have just begun to scratch the surface of the influence of dairy dam nutrition on the lifetime productivity of their calves, according to Billy Brown, assistant professor in the Department of Animal Sciences and Industry at Kansas State University.

In a presentation at the 2024 Cornell Nutrition Conference, Brown explored recent knowledge that can help dairy cows not just deliver healthy calves, but calves that perform better throughout their lifetimes, whether their career destination is the feedlot or the milking parlor.

Creating those successful calves is dependent on events through a number of biological touchpoints throughout their embryonic and fetal development, many of which are not completely understood. Brown says factors such as placental mass, blood flow and nutrient transport to the fetus can be critical.

Other effects may happen at the cellular level. Brown says “epigenetics” refers to DNA alterations that influence genomic material that ultimately activate cellular functions. By pulling the nutritional levers in dams that activate these changes, traits like growth, marbling and mammary gland productivity in their calves might be influenced for the better.

This type of research has been conducted for decades in the beef industry. A number of studies have shown cows that were supplemented with either energy or protein while pregnant produced calves with greater body weight from birth through slaughter, and heifers from supplemented dams reached puberty earlier.

Less-extensive beef research has also shown calves from supplemented dams showed statistical improvements in marbling, quality grades and ribeye area – an interesting finding considering the ever-growing proportion of calves from dairy dams that now are channeled into beef production.

But to date, dairy cattle research has not pursued this topic as extensively.

“There has been a flurry of recent and convincing research evaluating the negative impact of gestational heat stress on calf performance,” Brown says. “But comparatively fewer investigations have focused on effects of dam nutritional interventions.”

From the dam nutrition research that has been conducted in the dairy arena, one thing we have learned is simply feeding dams more is not a simple solution at all. While research has shown dairy calf birth weight increases about 4.5 lb. with each half-point increase in body condition (5-point scale), over-fat cows and first-calf heifers can experience calving difficulties and metabolic challenges in lactation.

“Data from other species indicate dams with excessive energy intake during gestation have deleterious effects for the neonate’s long-term ability to regulate feed intake and body composition,” Brown says. Those long-term effects, including over conditioning, higher metabolic disease incidence and reduced milk yield, have been shown to surface even more in the second generation from overfed dams.

Researchers have also learned high milk production does not guarantee dams will pass that genetic potential to their offspring. In fact, those calves might be hindered by their mothers’ milk production, as several studies have shown.

“Intuitively, the dams with greater milk production might have greater genetic merit for milk production, which could be passed along to their offspring,” Brown hypothesizes. “However, if epigenetic changes are occurring from reduced nutrient supply to the fetus while competing with the mammary gland, then this could limit the progeny milk supply potential.”

So, while hitting the sweet spot between too little and too much energy and protein is one challenge, Brown believes more knowledge could be drawn from the finer details of dairy rations.

Feeding rumen-protected choline to dairy dams has been shown to improve offspring performance in terms of birthweight; preweaning weight gain; feed efficiency; marbling; kidney, pelvic and heart fat; and insulin sensitivity. Rumen-protected methionine and lysine have been shown to positively affect offspring growth and weight gain, as have omega-3 fatty acid supplements.

Brown believes these, and other supplements, could help fine-tune lactating dairy rations to deliver the best possible nutrition package for both the lactating cow and her developing calf.

He says more research is needed, noting: “As this body of research grows, the future of the dairy industry may involve more deliberately setting up calves for success through the use of dam nutritional management during gestation.”

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From Brew to Moo: The Sustainable Dairy Practices at Ayers Farm

Thu, 28 Aug 2025 11:33:49 GMT

A good brew isn’t just for humans — it’s on the menu for the Holstein cows at Ayers Farm in Perryville, Ohio, too. This unique twist in cattle feed comes from an unexpected source: the Budweiser plant in Columbus. At Ayers Farm, home to more than 600 Holstein cows, this innovative use of brewer’s mash, a byproduct of the beer-making process, has become an integral part of their operation.

(Ayers Farm)

A Sustainable Diet
At Ayers Farm, sustainability is a key focus. The herd’s nutritionist orchestrates a delicate balance of crops and upcycled food byproducts to ensure the cows’ diet is both nutritious and environmentally conscious. Kathy Davis, a seventh-generation dairy farmer at Ayers Farms, emphasizes the importance of this approach.

“By using a byproduct from another process, we prevent it from ending up in a trash pile,” she says, underscoring their commitment to sustainable practices and innovative feed solutions that benefit their cows and the broader agricultural community.

Davis says they have been feeding distillers grains ever since she was in high school in the late ‘80s. She says farmers are the ultimate recyclers, adding they also include corn gluten, soybean meal and cottonseed to their cows’ diets.

“It was close by, and we could incorporate into the ration what would be beneficial,” she says, noting that prior to feeding distillers grains, the farm used potato waste from a nearby Frito Lay plant. “That is when we were feeding out steers. The potato starch content didn’t make it a good fit to feed our cows, but we’re always looking for benefits, and the distiller grain is economical, and our nutritionist was really excited about the possible benefits for it.”

(Ayers Farm)

Behind the Scenes
Ayers Farm isn’t just feeding its cows better — it’s also incorporating technology to enhance the health and productivity of their herd. From GEA activity monitors on breeding-age heifers, as well as lactating and dry cows to integrated feeding programs, plus DeLaval cameras in the maternity pens, the farm is leveraging tech to stay ahead. These systems provide valuable data that helps manage everything from health indicators to milk production metrics, ensuring issues are flagged before they become problems.

“It’s not just about milk production; it’s about having a good workforce and external partners, such as nutritionists and veterinarians, that help us achieve a sustainable, rewarding livelihood,” Davis shares. “Ultimately, it has to return a good livelihood to us and for our employees, so that our work-to-life balance is good, and we feel like we’re accomplishing something when we come to work every day.”

In addition to the cows, the Ayers have an equal number of replacement heifers and farm 1,500 acres. A total of 25 people work on their farm, which also includes owner-operators.

Challenges and the Future
Despite their advancements, like many farms, Ayers Farm faces challenges, particularly concerning labor and logistical hurdles in milk hauling. Yet, they are adapting, trying innovative solutions such as breeding and beef-on-dairy strategies to improve margins.

Looking ahead, steady communication and strategic planning are crucial for Ayers Farm, especially with generational transitions on the horizon. Davis’ father and uncle are in their ‘70s, while she and her cousin continue to accumulate more responsibilities. Succession planning not only involves the transfer of assets but also adapting the day-to-day share of operation responsibilities to ensure smooth management handoffs.

Ayers Farm is a testament to how traditional farming values can coexist with innovative practices. By incorporating distillers grains, optimizing feed through technology and planning for future generations, Ayers Farm continues to thrive in an ever-evolving agricultural landscape.

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Unraveling the Mystery of Hemorrhagic Bowel Syndrome in Dairy Cattle

Wed, 27 Aug 2025 13:55:54 GMT

An emerging, highly fatal intestinal disease of adult cows, hemorrhagic bowel syndrome (HBS), draws concerns from dairy producers, veterinarians and nutritionists, as it is also known as the sudden death disease of dairy cattle.

According to Angie Rowson, a board-certified dairy practice veterinarian who has been working with HBS for over two decades, there is still not much known about HBS. She says producers have either never heard of this disease, have sporadically seen HBS on their farm, or are constantly battling the disease.

HBS is characterized as an acute and sometimes massive hemorrhage in the small intestine, which can subsequently lead to the formation of intraluminal blood clots and obstruction. Furthermore, affected cows suffer from the collective effects of blood loss, intestinal obstruction and necrosis of the bowel.

As a veterinarian, Rowson’s boots-on-the-ground work in central California allowed her to see firsthand the impact of this fatal disease in dairies, as she performed several HBS necropsies in dairy cattle.

“One herd I worked with was losing eight to 10 cows a month from HBS,” she says. “We wanted to get to the root of why this was happening. Not just because of the financial loss, but also because of the pain associated with the disease.”

Despite being a fatal disease, little attention regarding funding and research has been conducted. Many details surrounding HBS, including contributing factors, continue to be a mystery.

“It is frustrating that no one in the U.S. is doing any new research on HBS,” Rowson adds. “The problem is we cannot recreate it in a lab, so we don’t know exactly what causes HBS. We only know bits and pieces and that the cause is multifactorial.”

Scott Bascom, technical services manager for Phibro Animal Health, agrees much is unknown about what causes some cows to develop HBS and not others.

“HBS cases are most common following stressful periods in a cow’s lactation cycle such as calving and early lactation, when cows are subject to several different stressors. These stressors can reduce immune function,” Bascom says. “The cow’s immune system plays a role in whether a cow becomes an HBS cow. If the cow’s immune system becomes compromised the cow is more susceptible to the effects of invasive molds, toxins and pathogenic intestinal flora, which can lead to HBS.”

Common Denominator
Any dairy breed can be associated with HBS, though Brown Swiss have been reported to be more predisposed. While HBS is reported to be sporadic, some dairies will have multiple cases within a few days. Other common denominators of cows with HBS are:

Second lactation or greater (although there have been cases of younger lactation cows with HBS)
Between 100 and 120 DIM (though HBS can occur at any time during the lactation cycle)
Producing larger volumes of milk and consuming larger volumes of feed
Immunosuppressed
Larger, higher production herds

Rowson states that often cows who are higher in production levels consume a large volume of feed, and the diet at that stage of lactation is often high in protein and energy but lower in fiber. She also notes that feed is passing through the intestine at a faster rate. However, little research has been conducted to determine what impact this has on developing HBS.

“Research from University of California-Davis shows the bleeding starts in the wall of the intestine, but we don’t know what starts that process,” Rowson states. “Maybe the diet the cow is consuming, specific pathogens or her intestinal motility contributes?”

Although it is more common in the fall and winter, HBS can happen any time of the year. Bascom says this is likely a result of dairies starting new crop feed coupled with inadequate fermentation. Feed management goes beyond silage, and Bascom reminds producers that mold can occur in other feedstuffs.

“Silage management practices at harvest and feed out can minimize the growth of molds,” Bascom says. “At harvest, put it up at the right moisture, pack it and cover it. At feed out, manage the face to reduce mold growth and avoid feeding moldy silage.”

HBS Symptoms
Diagnosing HBS based on clinical signs alone is generally not possible, because these symptoms can also be found in other diseases. Clinical symptoms connected with HBS include:

Sudden onset of depression
Dehydration
Decreased feed intake and milk production
Abdominal distension and pain
Either no feces or a decreased amount of feces that are dark and contain clotted blood

An additional symptom associated with HBS is cold extremities. A rectal examination may reveal distended loops of the small intestine or even no stool, due to the blockage. Often, most cows appear to be in good health before the development of this disease, hence the moniker “sudden death disease,” as many times a producer finds a cow down or even dead.

Rowson notes HBS is often either under- or overdiagnosed, and she says the latter is frequently the case.

“Producers do not always perform a necropsy and chalk a sudden death cow to hemorrhagic bowel syndrome,” she says.

A proper diagnosis is often made through necropsy, while ultrasound is only able to make a definitive diagnosis of HBS a quarter of the time. Exploratory surgery is needed to confirm and treat HBS, but this can be expensive and is time-sensitive, as cows would need to be rushed to a veterinary hospital or veterinary medical school.

Rowson says statistics show the University of Wisconsin veterinary school has a high success rate with surgical treatment, but they have also reported a high rate of recurrence, with nearly 40% recurring within the first 12 months.

“We don’t know exactly why some cows that survive the initial surgery develop HBS again. It’s been speculated that there might be a genetic predisposition to HBS or maybe, management practices designed to achieve high milk production increases the risk of developing HBS, and these cows are going right back into that environment,” Rowson states.

Management Tips
Make no assumptions, Rowson advises. When a cow dies of what is believed to be HBS, “open her up,” she says. “It could be a hardware disease or abomasal ulcers or something else.”

Bascom agrees and says producers can’t properly evaluate the effectiveness of HBS mitigation strategies (i.e. feed additives, management changes, etc.) if they don’t accurately know why cows are dying.

“Oftentimes, producers might make an abrupt change to the ration, taking out a supplement because they feel like it’s not working,” he says. “However, without performing a necropsy, they easily could be dealing with a completely different cause of death.”

Recommended management tips to help prevent HBS:

Make sure feed is in front of the cow 22 to 24 hours a day
Push feed up frequently
Prevent sorting and slug feeding
Ensure enough fiber is in the ration
Use a consistent time for feeding, day after day
Limit spoilage with haylage and corn silage by ensuring proper fermentation, packing right, chopping at the optimal moisture level, using an inoculant
Remove mold before feeding — pitch the crust on the silage and side walls

Takeaway Advice
Both Rowson and Bascom encourage limiting stressors that cows encounter. In addition to monitoring feed quality, be sure to evaluate and manage the cow’s environment for potential stressors. Excessive cow movements that disrupt an established social order can cause cows to go off feed. Minimizing overcrowding, focusing on cow comfort and keeping heat stress at bay can lead to a less stressed cow and, therefore, help her maintain an overall healthier immune system.

Furthermore, minimizing the stressors that cows are subject to, especially around the time of calving and early stages of lactation, is essential. Bascom notes some cows are more susceptible to the effects of stress than others, which can affect immune function and predispose cows to develop HBS as well as other disorders.

Several feed additives are in the marketplace claiming to boost the immune system. While feeding additives can help boost immune health, Bascom reiterates that identifying and minimizing stressors is key.

“A cow can live in the best environment and still be exposed to stressors during a normal lactation cycle, because events such as calving and dryoff are stressful,” Bascom adds. “Try to recognize and manage the stressors, so when a cow experiences stressful events, like calving, she is better positioned to handle that stress.”

To better understand this fatal intestinal disease that could be impacting your herd, don’t make assumptions. Learn what the true cause is behind the death of any cow and then manage the symptoms from there.

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The Next Frontier of Cow Nutrition is Encapsulated

Thu, 28 Aug 2025 13:06:55 GMT

Consumption trends are driving the milk industry like never before. Weight loss drugs, body building supplements, diets for the elderly and the need to maintain muscle mass in an aging population. A proactively engaged consumer (Prosumer) is demanding a diversity of food options to match environmental concerns, animal welfare, ethnic diets, etc. The influence of social media on consumption is pervasive on the food shelves of supermarkets and convenience stores. Visiting a grocery store in a large city is more like a safari — a mixture of entertainment and storytelling — than about the actual nutritional needs of the consumer.

Milk processors have struggled to keep up, and the milk shelves have never been fuller of a more diverse range of options. The range of cheese, yogurt and ice-cream labels would challenge the average recent graduate of the food science programs of our best Universities.

What can dairy producers do?

1. Genetics: The recent and dramatic advances in reported milk components in the U.S. dairy herd has been nothing short of extraordinary. Cobank reports the 2024 U.S. butterfat levels reached 4.23%, and proteins are now at 3.29% — a record by historical standards. This has been driven by better genetic selection, particularly in Holsteins, and feeding and managing those genetics for optimal performance. It is reasonable to expect further improvements in bovine genetics will continue these trends over the coming decade.

2. Feeding for milk components: Traditionally, nutritionists have used least-cost feed formulation software in order to achieve the most cost-effective milk production. Often decisions were taken based on single ingredient digestibility and not on how a diet affects rumen fermentation, ruminal biomass or the absorption of those nutrients in the lower gastrointestinal tract. The use of bypass proteins and anionic salts have shown what is possible when ingredients can avoid degradation by rumen micro-organisms. The use of yeast cultures is another approach, enhancing rumen fermentation of fibers and acidity (pH) to produce more microbial protein, and eventually increased milk components.

3. Precision feeding for milk components: The last 10 years have seen an explosion in the use of encapsulated ingredients to bypass the rumen, allowing this concept to go from niche to mainstream. The most obvious example of this has been Adisseo’s Smartamine & Meta-Smart, and protected forms of methionine are now said to be used in over 70% of the top-producing dairy herds. As one New York dairy farmer said to me, “When my nutritionist forgets to put it in the feed, I see the changes in the milk tanks within days.”

Globally, another dozen companies have entered the fray. The new leaders are all looking beyond methionine to a range of nutrients that both increase milk production, milk components and intestinal health. Balchem (Lysine, Choline), Jefo (B-Vitamins, essential oils), ADM, Kemin, Alltech (nonprotein nitrogen) are just some of those leading in this field. The excitement of using microencapsulation is that it allows these feed ingredients to bypass rumen degradation, effectively turning the ruminant into a monogastric. In other words, feeding a cow as though she was a pig.

A demonstration of the scale of excitement around how encapsulation is seen as a game changer is that Jefo recently opened a new $100 million factory in Canada just to meet the needs of their North American customers — focused on delivering combinations of ingredients (Matrix technology) to improve cow health, productivity and fertility.

What’s next?

Artificial intelligence will most likely increase the pace of change in our cow’s nutrition. Understanding how to influence the ruminal microbiota through nutrition, more precisely and in real time, will move science forward. Traditional rumen models such as the artificial rumen simulation systems (e.g. Rusitec), predictive models such as the Cornell CPCPS Model and INRA Systali (PDI) in Europe, are being supplanted by AI-based systems. Equally using sensors in the rumen (digital boluses, Smaxtec) and in-line and individual cow milk sensors (Labby, SomaDetect), will give farmers the ability to see the benefits of delivering nutrition in real time. Feeding precisely means in the right place, in the right form, at the right time. Already Canadian farmers have reported dramatic benefits of encapsulating all of the micronutrients fed to their cows in a single delivery, on milk components, somatic cells and fertility. This will undoubtedly be the future: reimagining all aspects of feeding cows.

When it comes to nutrition, it’s like Dorothy said in the Wizard of Oz: “We aren’t in Kansas, anymore!”

It's Time to Go Back to the Feedbunk Managment Basics

Tue, 19 Aug 2025 14:45:40 GMT

How feed is managed at the bunk can have a bigger impact on cow health and production than farmers might think. Seemingly small details such as timing, consistency or mix quality can make a significant difference in how cows eat and perform.

Getting feedbunk management right starts with going back to the basics. Dr. Kirby Krogstad, assistant professor of dairy nutrition at Ohio State University, stresses that clear routines, attention to detail and teamwork at the feedbunk are the foundation for keeping cows healthy and productive.

During a recent conversation on the “Dairy Health Blackbelt Podcast,” he shared practical tips and strategies that dairies of all sizes can use to improve herd performance.

“One of the fundamentals that constantly needs revisiting is how to manage a bunk properly,” Krogstad says. “If you feed cows, do you have a written protocol for how you want your cows fed and how often you want feed pushed up? If you don’t have that, you need to start there.”

Make a Plan and Stick to It

For many dairies, labor availability and time management are ongoing challenges. Krogstad notes that feed push-ups don’t always happen as often as they should, and feeding times can vary. That can leave cows without feed for an extended period of time, which can reduce intake, upset the rumen and lead to dips in milk production.

A written feeding protocol is the first step. It should outline exactly how and when feed is delivered, how often push-ups occur and what to do if feed runs low. Once everyone knows the plan, it becomes easier to train employees, maintain consistency and monitor compliance.

“You have to implement a program with yourself, your staff, your family — whoever does the feeding — in mind. Then you can start using additional in a more effective way,” Krogstad says.

Simple Tools Can Make a Big Difference

Technology doesn’t have to be complicated or expensive. Krogstad recommends using time-lapse cameras as a simple way to track feed delivery and cow behavior.

“Hang cameras to see when feed is being pushed up, when cows are coming to the bunk and to monitor out-of-feed events,” he says. “Sometimes what we think is happening is not actually happening. A camera can show you the gaps and help you fix them.”

These cameras provide an objective view of daily routines and can highlight inconsistencies between written protocols and what actually happens. By spotting problems early, producers can adjust routines before they affect production or cow health.

Check Your Mix

Even if feed is delivered on time, the mix itself has to be consistent from one end of the bunk to the other. Krogstad suggests using a Penn State particle separator to check feed uniformity. Uneven mixing can result from operator error, improper ingredient order or worn mixer components such as kicker plates, knives or restrictors.

“If the mix isn’t consistent, you might have an operator error or equipment problem,” Krogstad explains. “Fixing these issues ensures every cow gets the same quality feed, which keeps intake steady and production predictable.”

Feed Is Too Valuable to Waste

Krogstad also emphasizes the importance of paying close attention to bunk management, especially given the high cost of feed and the challenges of maintaining reliable labor on many dairies.

“Nutrition is a huge cost,” he says. “It puzzles me why people don’t pay more attention to this when it’s the biggest input you have on your dairy.”

Feed waste can happen in many ways. Uneven mixing in the TMR can leave some cows with too little of key nutrients and others with more than they need, which can lead to portions of feed being pushed aside or left uneaten. Gaps in feed delivery or infrequent push-ups can also cause cows to compete for feed or wait for fresh feed, leaving bunk space empty or spoiled feed behind. Even small amounts of leftover feed add up to significant costs over a year.

By paying closer attention to how feed is delivered, checking the mix for consistency and keeping push-ups regular, producers can reduce waste.

“A little extra effort each day at the bunk can save a lot of feed and prevent drops in production,” Krogstad notes. “It’s one of those areas where attention to detail really shows up on the bottom line.”

Focus on Consistency

Krogstad stresses that a reliable routine is the key to an efficient feedbunk. That means consistent feeding times, consistent push-ups, consistent mix quality and consistent adherence to protocols. When cows can rely on a steady routine and uniform feed, their intake stabilizes, rumen health improves, and milk production becomes more predictable.

By focusing on these fundamentals, producers can improve cow performance, reduce feed waste and run a more efficient operation. Small, consistent improvements in the bunk add up to better herd health, higher milk production and stronger profits for the farm.

Could Water Additive Reduce Cattle Methane Output?

Mon, 04 Aug 2025 15:45:59 GMT

As researchers strive to reduce methane emissions in the agricultural sector, grazing animals have not been privy to current feed-additive technologies. That could change soon, with a new, commercial product under development called Rumin8 .

Rumin8 is under development by a climate technology start-up company based in Perth, Australia. It contains a compound developed from rangeland plants and red seaweed. The organic active compound, Tribromomethane (TBM), is produced via a pharmaceutical-grade manufacturing process.

More than a decade of research has explored its efficacy in reducing methane output by targeting the methanogenic pathways in ruminant livestock.

As a feed additive, Rumin8 has been shown to reduce methane emissions in confinement-housed dairy and feedlot cattle by 50 to more than 90%.

But according to the Rumin8 founders, at any one time 96% of the cattle population in Australia, the U.S., Brazil, and New Zealand are raised in grazing systems, and there currently no methane-reducing additives available for these cattle.

A recent study conducted at Australia’s University of New England evaluated the efficacy of delivering a water-based formulation of Rumin8 to cattle through water troughs. Compared to a control group receiving no treatment, the Rumin8-treated cattle achieved an 81% methane yield reduction.

In the same study, an oil-based formulation was incorporated into a feedlot ration, producing a 95% reduction in methane yield. But the still-respectable 81% methane reduction via water delivery could still be highly valuable, given the large population of cattle in either remote rangeland operations or those with fewer animal handling touchpoints. And even in confinement housing, water dosing may be more practical and convenient, depending on the operation’s management structure and animal care routines.

Rumin8 founders say the product could be integral to the production of lower-carbon meat and milk. They emphasize that reducing ruminant methane enables animals to convert otherwise lost energy into increased productivity. Initial research trials have indicated productivity gains in the neighborhood of 9%.

To date, Rumin8 has been approved in feed additive form by regulatory bodies in New Zealand and Brazil . The product remains in the approval review process with the U.S. Food and Drug Administration’s Center for Veterinary Medicine.

Company officials say they are working diligently to accelerate access of Rumin8 products into the hands of producers, with “a view to reduce livestock methane emissions and improve productivity.”

Not All Milk Fever is the Same

Tue, 29 Jul 2025 18:10:19 GMT

For dairy farmers and nutritionists alike, keeping fresh cows on their feet and healthy becomes a priority the moment they enter the dry-cow pen. This includes working to stay ahead of hypocalcemia, also known as milk fever.

On a recent episode of the “Dairy Nutrition Black Belt” podcast, Laura Hernandez, professor of lactation physiology at the University of Wisconsin-Madison, shares her perspective on calcium metabolism, prevention strategies and why a slight drop in calcium might not always be a bad thing.

Types of Hypocalcemia
Although hypocalcemia is often discussed as a single issue, Hernandez emphasizes that it presents in different forms, each with unique timing, symptoms and consequences for cow health and productivity.

1. Classic Hypocalcemia
This is the textbook case most producers are familiar with. It typically occurs within the first 24 hours postpartum and may present as clinical milk fever or more subtly as subclinical hypocalcemia. Cows often appear weak, with muscle tremors, cold ears and difficulty standing.

2. Delayed Hypocalcemia
In this less recognized form, cows appear normal for the first two days postpartum with adequate blood calcium levels. The drop doesn’t come until day four or later, at which point cows may experience clinical or subclinical symptoms.

“Delayed hypocalcemia is sneaky,” Hernandez says. “You might think a cow is in the clear, only to have her crash a few days later.”

Identifying delayed hypocalcemia often requires proactive monitoring of blood calcium levels beyond the immediate post-calving period. Herds may benefit from targeted sampling or observation of early warning signs like reduced feed intake or lower activity levels.

3. Persistent Hypocalcemia
This form involves cows that start with low calcium levels on day one or two and fail to recover by day four. These animals are particularly at risk.

“These cows likely will have more diseases like displaced abomasums, retained placentas and ketosis,” Hernandez notes. “They’ll also have collectively lower milk production over the course of their lactation and are more likely to leave the herd.”

Persistent cases are often tied to underlying issues with calcium mobilization and metabolic health. Identifying them may require a combination of bloodwork and tracking clinical outcomes across early lactation.

4. Transient Hypocalcemia
According to Hernandez, one of the more surprising developments in hypocalcemia research is the discovery of a form that may actually benefit cows: transient hypocalcemia.

This short-term drop in blood calcium occurs within the first 24 to 48 hours postpartum but resolves on its own by day four. Research from Dr. Jessica McArt’s lab at Cornell suggests cows in this category often outperform their peers.

“What she’s found in her production data is that indeed these cows make more milk, they have less disease and they often make more milk than the cows that are never subclinical,” Hernandez says.

She hypothesizes transient cows are more efficient at activating key hormones that regulate calcium absorption and mobilization, allowing them to adapt quickly to the demands of early lactation.

“Calcium status is a hormone-driven process,” she adds. “If we do too much to keep calcium up, sometimes the cow can’t reset herself and have that trigger of negative feedback so she can mobilize or absorb more calcium.”

Using Nutrition as Prevention
As with many transition cow issues, prevention remains the best strategy. But Hernandez cautions against a one-size-fits-all mindset.

“Farms do this very differently, and it’s not a one-size-fits-all approach,” she says. “You have to take into consideration management strategies, what you can get your workers to do and what the cost-benefit ratios are.”

Several nutritional tools are available to help reduce the risk of hypocalcemia:

Low potassium diets: Often used in dry cow rations to promote calcium mobilization.
Calcium binders: These products can help prevent calcium absorption during the prepartum period, which can prime the body for efficient mobilization postpartum.
Phosphorus binders: Hernandez notes this is an emerging area of interest, especially as phosphorus metabolism receives renewed attention. She notes high dietary phosphorus can interfere with calcium absorption and regulation, especially during the transition period.

“Phosphorus has kind of been the forgotten mineral,” she adds. “But it’s coming back into the conversation, not just from a nutrition standpoint, but also for manure management and sustainability.”

Phosphorus binders may offer a tool to fine-tune the balance and support better overall mineral management — but more research is needed to determine how and when to use them most effectively.
DCAD (Dietary Cation-Anion Difference) diets: One of the most widely used approaches, DCAD diets create a mild metabolic acidosis prepartum to increase calcium mobilization from bone and absorption in the gut.

DCAD remains a cornerstone strategy when well managed.

“It works extremely well but does have some management input that needs to happen in order to keep it working,” Hernandez adds.

In a recent study, her team compared different dietary strategies, including a calcium-binding product that actually functioned more like a phosphorus binder. While the sample size — 40 cows per treatment — was too small for definitive conclusions, it highlighted the complexity of mineral interactions and the need for ongoing evaluation.

“Not all these dietary strategies are equal in what they do, and we really should make a good attempt to understand that,” she says.

Looking Ahead
Although hypocalcemia has been studied for decades, Hernandez stresses the need for continued research, particularly to better support cows with transient hypocalcemia and to prevent the delayed and persistent forms that contribute to long-term health issues and reduced milk production.

“We would really have to do a larger study to get at: What’s the true production response? What is the true health response?” she says. “But the goal would be to keep cows in the herd longer and also to keep them healthier and producing at a maximal level.”

Hernandez also highlights a growing interest in phosphorus — a mineral that has received relatively little attention in recent years.

“Phosphorus is like a lost mineral from what I could tell in the literature,” she adds. “No one’s been really doing much with that until recently, and so I think there’s some opportunity to understand that as well — especially from a manure and nutrient management standpoint.”

As Hernandez notes, milk fever can present itself in many different ways and at different times. That’s why it’s important to work closely with your nutritionist and veterinarian to develop a plan that fits your herd. Whether it’s fine-tuning dry cow diets, monitoring calcium levels after calving or adjusting treatments based on cow response, a team approach can help catch issues early and keep fresh cows off to a strong start.

Prep for the Seasonal Colostrum Slump: Expert Tips to Keep Your Freezers Full

Tue, 22 Jul 2025 18:36:09 GMT

Right now, it might feel like colostrum is in no short supply. Cows are calving, freezers are full and you might think you’re sitting pretty when it comes to inventory for the remainder of the year. But as the days get shorter and temperatures begin to cool, many operations will start to experience a perplexing challenge when it comes to feeding calves – lower colostrum yields.

“Many farms experience a common issue that leaves farmers and calf managers scratching their heads: declines in colostrum production during the fall and winter months,” says Katelyn Goldsmith, dairy outreach specialist at the University of Wisconsin-Madison. “This problem can make it difficult to quickly feed calves high-quality colostrum in adequate quantities.”

While this seasonal slump is common, it doesn’t have to catch you off guard. With the right planning and management, you can stay ahead of the dip and maintain control over your colostrum supply.

Why Does it Happen?

While there’s no sure answer as to why colostrum production takes a dip during the fall and winter, research points to two key factors: shorter daylight hours and lower temperature-humidity index (THI).

As days shorten after June, cows receive less light, and cooler, drier conditions set in. Both have been linked to lower colostrum yield. Goldsmith notes that in one Texas study, average colostrum production fell from 14.5 lb. in June to just 5.5 lb. in December. Older cows were especially affected.

Similar seasonal declines have been observed in studies across New York, Michigan and Europe. While genetics, nutrition and lactation history play a significant role, the consistent pattern suggests that reduced light and lower THI are major drivers of the slump.

How to Prepare

To minimize the impact of seasonal dips, Goldsmith recommends focusing on what you can control. She provides the following strategies to help you get ahead of the slump:

Pay Attention to Dry Period Length: Ensuring cows have an adequate dry period length is crucial. Cows with short dry periods tend to produce lower yields of colostrum. Goldsmith notes a 45- to- 60-day dry period is considered ideal.
Minimize Environmental Stress: Dry cows should have consistent and adequate access to feed and water, especially during the summer months. Limited or restricted feed and water access can reduce dry matter intakes, negatively affecting colostrum production.
Encourage Colostrum Let Down: During milking, maintain a calm and low-stress environment. Ensure cows are properly prepped prior to attaching milking units and that they are completely milked out before unit removal.

“Colostrum quality decreases when harvest is delayed,” she adds. “For best quality, harvesting colostrum less than 8 hours post-calving is recommended.”
Consider Oxytocin for First-lactation Cows: Administering oxytocin has been shown to promote colostrum let down and increase yield in first-lactation cows. Recent research found first-lactation cows produced 3.5 lb. more colostrum when administered an appropriate dose of oxytocin compared to untreated cows. If considering this route, farmers should discuss with their veterinarian whether or not using oxytocin fits with their operation.
Assess Feed Additives: Recent studies have found feed additives such as choline or calcidiol in dry cow diets have improved colostrum yields. When evaluating feed additives, ensure they are research-backed products that have been assessed for their impact on colostrum production.

Managing Supply When Yields Are Low

Even with the best preparation, there may be times when colostrum is in short supply. That’s where smart inventory management comes in.

“A well-stocked colostrum bank can be a lifesaver during periods of low production,” Goldsmith says. “Use a tool such as a Brix refractometer to assess colostrum quality and store it accordingly.”

And when stored colostrum isn’t available, be ready with a replacer. Goldsmith recommends selecting a replacer — not supplement — that will provide newborn calves with 300 grams of immunoglobulin G (IgG).

“Since providing extra daylight is not possible for many farms, the potential adverse effects of the colostrum shortage must be addressed through well-planned banking of high-quality colostrum and the use of colostrum replacement strategies when necessary,” Goldsmith says.

And as always, be sure to follow proper storage practices.

“Colostrum should be refrigerated for no more than one day or frozen for up to a year to maintain quality,” she says. “Properly label colostrum and store it in a clean environment to prevent contamination.”

Stay Ahead of the Slump

Seasonal drops in colostrum can be frustrating but it helps to know why they happen and how to prepare. Shorter days and cooler temps can lower yields in fall and winter, but good management can make a difference. Focus on a proper dry period, build a strong colostrum bank and keep quality replacers ready to protect calves when inventories get low. With planning, you can keep freezers stocked with high-quality colostrum to ensure calves stay well nourished.

Your Next Read: Kefir for Calves is on the Menu

Don't Settle for Mediocre: How to Make Moderate Quality Colostrum Work

Thu, 17 Jul 2025 16:08:18 GMT

As all calf feeders know, not all colostrum is created equal. Some fresh colostrum is rich in immunoglobulin G (IgG) and ideal for newborn calves. Some is poor in quality and unsuitable for feeding. And then there’s the “Goldilocks” kind that falls somewhere in the middle. It’s not too bad but not quite good enough either.

This in-between category often leaves producers in a bind. Do you feed it as-is and risk inadequate passive transfer? Do you discard it and rely on frozen reserves or replacer? Or is there a better way to make moderate-quality colostrum just right?

A recent study, conducted by the University of Minnesota and published in the Journal of Dairy Science, explored a practical solution: enriching moderate-quality maternal colostrum with commercial colostrum replacer (CR) powder. Specifically, researchers asked whether the powder could be added directly to the colostrum without being reconstituted in water first and still deliver strong immunity to calves, without negative effects on health or digestion. Their findings suggest a straightforward way to make colostrum feedings more consistent when top-quality colostrum isn’t on hand.

A Practical and Safe Option
The researchers found that adding dry CR powder straight into moderate-quality maternal colostrum is an effective way to enhance its immune benefits. Calves fed the enriched colostrum reached blood IgG levels that were statistically similar to those fed naturally high-quality colostrum. And importantly, these calves did not experience digestive upset, poor appetite or abnormal behavior.

The researchers compared this method to one where the CR was first mixed with water and then added to the colostrum. While both methods improved IgG levels over unenriched colostrum, the direct-mix approach performed slightly better. In addition, it avoided the added liquid volume, which can make feeding more difficult, especially when tubing calves.

One concern with enriching colostrum is how the added ingredients might change the colostrum’s physical properties, particularly its concentration. Osmolality, or the concentration of dissolved particles in colostrum, can affect how easily a calf digests its first feeding. In this study, however, adding dry colostrum replacer powder directly into maternal colostrum did not appear to cause any digestive issues or affect calf performance.

Not All Powders Are Created Equal
While the results are encouraging, the researchers say it is important to note this study evaluated only one commercial colostrum replacer product. Replacers can vary widely in their ingredients, solubility and osmolality. Thus, a method that proves effective with one product might not produce the same results with another. For that reason, any adjustments to colostrum feeding protocols should be made in consultation with a veterinarian or nutritionist.

Still, this method offers flexibility. On days when your colostrum supply is good but not great, enrichment with dry powder might be a simple and cost-effective way to ensure every calf gets the strong start it needs.

Use Frozen Colostrum Within 8 Months for Best Results

Wed, 09 Jul 2025 21:36:59 GMT

Keeping frozen colostrum on hand is a practical part of calf care. It helps ensure newborns get what they need when fresh supply is limited or timing isn’t ideal. But as that freezer fills up, it’s worth asking: How long can colostrum sit before its quality starts to decline?

“Saving excess colostrum is a great way to make sure calves get what they need, even when fresh supply is tight,” says Sarah Morrison, research scientist at the William H. Miner Agricultural Research Institute. “But it’s not just about having it on hand, it’s about protecting its quality. And that starts with how we freeze, store, label and thaw it.”

Historically, it was commonly accepted and promoted that colostrum could be stored in a non-frost-free freezer for up to a year. But new research from Cornell University (JDS Communications, 2025, Vol. 6:406–410) has taken a closer look at frozen colostrum over time. Researchers evaluated samples stored at -20°C (-4°F) for up to one year and analyzed key indicators including Brix %, immunoglobulins (IgG, IgA, IgM), insulin and total plate count.

They found that IgM, IgA and bacteria counts held steady, but IgG, insulin and Brix % decreased as freezer time increased. After 32 weeks, about eight months, IgG had declined by roughly 8% compared to fresh colostrum.

“That tells us that colostrum is still usable after eight months in the freezer, but it might not be your best option for a first feeding,” Morrison explains. “The first feeding is your one chance to really nail passive transfer, so you want that IgG level to be as strong as possible.”

Instead, colostrum older than eight months might be better suited for second feedings or backup scenarios while newer, high-IgG colostrum should be prioritized for a calf’s first meal.

Not All Freezers Are Equal
The freezer itself plays a key role in maintaining colostrum quality. Many farms rely on chest freezers, but Morrison warns against using frost-free models.

“Frost-free freezers go through cycles to prevent ice buildup, and those temperature changes also affect the colostrum,” she says. “If there’s any bacterial contamination, that fluctuation can give it a chance to grow. And the proteins we’re trying to preserve, especially IgG, can degrade when frozen and thawed repeatedly.”

Instead, use a non-frost-free freezer set at -20°C (-4°F). Label each colostrum container with the cow ID, date of collection and Brix % reading if available. While Brix will decline over time, it’s still a reliable quality indicator when taken at the time of collection.

“When considering the lower Brix %, I would encourage the use of this at the time of colostrum collection and not worry about measuring this after it’s been frozen,” she says.

Smart Thawing and One-Time Use
Thawing colostrum correctly is just as important as storing it. Labeling might seem like a small step, but it’s crucial for inventory management and quality control. Without it, producers might unknowingly feed colostrum that’s aged past its optimal window.

“On the label, include cow identification number and date of collection,” Morrison advises. “Furthermore, if your farm is measuring colostrum quality with a Brix, include the number on the label.”

Just as important as how colostrum is frozen is how it’s thawed. Mishandling during this phase can reduce the effectiveness of even the best-quality colostrum.

“When thawing, use a hot water bath of 40°C (104°F),” she says. “Warmer temperatures >60°C (140°F) should not be used as this can denature the proteins in the colostrum.”

And once it’s thawed, don’t plan to refreeze it.

While the Cornell study used high-quality colostrum, more research is needed to understand how lower-quality samples respond to long-term freezing. Even so, the key takeaway is to label clearly, manage by collection date, and protect frozen colostrum as a valuable part of your calf care program.

“Colostrum isn’t something we can afford to take chances with,” Morrison says. “It’s worth asking: Do you know how old the colostrum is in your freezer? Are you using the oldest first? Maybe it’s time to add a ‘Best By’ date on your bags.”