Diagnostics

Your Vet Recommended RT-PCR for Mastitis — Now What?

Fri, 10 Apr 2026 15:03:57 GMT

If your veterinarian is recommending RT-PCR (real-time polymerase chain reaction), it’s usually tied to a specific frustration point on the dairy. That might be repeated “no growth” culture results, ongoing contagious mastitis challenges or a high number of clinical cases without clear answers.

As Dr. Jim Rhoades, veterinarian with IDEXX, put it:

“PCR is not new, but it may be new to some of our producers. It’s a tool that is really applicable to diagnosing mastitis on commercial dairy farms now. Getting good, timely information to make management decisions is probably undervalued in many cases.”

At its core, this isn’t about adding another test. It’s about getting clearer, more actionable information to guide management decisions. RT-PCR is one key in the advancement of technology for mastitis detection and prevention .

What RT-PCR Actually Does

RT-PCR works by detecting the genetic fingerprint of bacteria rather than trying to grow them in the lab.

Here’s the simple version:

Every pathogen has unique DNA. RT-PCR takes a milk sample mixed with fluorescence-tagged pathogen-specific DNA primers and runs it through repeated heating and cooling cycles that facilitate the amplification of the target pathogen DNA. As that DNA builds up through the cycles, a fluorescent signal increases, and once that signal crosses a defined threshold, the test reads as positive.

This amplification process is what allows PCR to detect even very small amounts of bacteria that culture might miss.

“PCR is grounded in specific genetic sequences that make the bacteria the bacteria. It is very specific to a single target. We’re not casting a wide net to see what grows. We’re looking for specific pathogens or groups of pathogens,” Rhoades explains.

How to Interpret a PCR Result

Instead of colony counts, PCR reports a cycle threshold, or Ct value. This reflects how many amplification cycles, the repeated heating and cooling cycles, were needed before bacterial DNA was detected via fluorescence.

The key takeaway is straightforward:

Low Ct = more bacteria present
High Ct = less bacterial DNA present

That’s the opposite of what most people are used to with culture, but once understood, it becomes a reliable way to gauge how significant a result may be.

Why PCR Can Still Be Positive When Culture Isn’t

In practical terms, culture depends on live bacteria being able to grow, while PCR detects DNA whether or not those organisms are still viable, which is why it can pick up infections that culture misses.

“With PCR we can have positive results that may have been negative with culture. It can give us information we may not have gotten from culture,” Dr. Pamela Adkins, associate professor of food animal medicine at the University of Missouri, says. “About 30% of clinical mastitis cases will come back culture-negative. When we use PCR, we find only 8% of those cases are actually negative.”

In practice, PCR is especially useful when:

Bacterial levels are too low to grow in culture
The cow has already started clearing the infection
Sample handling reduces bacterial viability

One of the most important things to understand is that PCR detects DNA, not necessarily live bacteria.

“The immune system may clear the pathogen, which is great. If that happens too quickly, we may not get an answer from culture, but the PCR will still be positive,” Adkins explains.

This is where interpretation is important. A PCR-positive result doesn’t always mean an active infection that needs treatment; it may reflect a recent infection that has already resolved.

Where PCR Fits and What to Do With It

PCR is best thought of as part of a broader diagnostic approach rather than a replacement for existing tools. Rather than replacing culture, it complements it by adding speed and sensitivity, particularly in situations where traditional methods fall short.

“These are all tools and we need to use all the tools in our toolbox,” Rhoades says.

In practice, PCR adds the most value when it helps you step back and understand what is happening at the herd level. It can identify infections that would otherwise be missed, clarify what pathogens are driving mastitis on your farm and point toward more effective prevention strategies.

For producers, that translates into a few key advantages:

A clearer picture of what’s actually in the herd
Better ability to reduce spread of contagious pathogens
More confidence in targeted, cost-effective decisions

When used correctly, RT-PCR can give you the information needed to make better decisions with fewer surprises, fewer missed infections and more control over the problem.

To learn more about how mastitis detection, prevention and treatment are changing, check out the following episode of “ The Bovine Vet Podcast ”.

How to Manage Coccidiosis Risk in Weaned Calves: What Producers Need to Know

Mon, 08 Dec 2025 14:41:27 GMT

A ranch weans four groups of calves, all from separate pastures and breeding groups. They are placed in the same drylot to be fed, and three weeks later, some calves are dealing with bloody diarrhea. With the time of year and situation described, coccidiosis is high on the list of possible issues.

In the most recent episode of the “ Bovine Science with BCI ” podcast, Kansas State University veterinarians Bob Larson and Brad White look at this case of potential coccidiosis in weaned calves.

Larson explains there are other issues that can cause bloody diarrhea, like Salmonella or any other intestinal disease that cause damage to the intestinal lining.

One of the first factors to investigate is feed rations. In this case, these calves were being fed a corn, corn-gluten and soy hull mix with free-choice hay. Larson explains this is a rather fibrous diet with less starch, therefore acidosis and other related digestive tract issues can be eliminated.

The Prognosis

Studying the feces is another way to analyze the situation. Typical signs of acidosis include runny feces, sometimes containing gas bubbles, according to Larson. But he also adds that this is never a perfect test and to keep your options open when determining the prognosis.

To further understand feces tests, Larson explains that frank blood, often appearing bright red in color, indicates the damaged gut is further back in the digestive tract and the blood hasn’t been digested. When the blood is digested, like with abomasum ulcers or earlier tract issues, it appears black in color with a tar-like texture. In this ranch’s case, calves are presenting frank blood.

For more diagnostics, Larson says fecal floats are an option. There are different types of coccidia organisms that infect cattle in varying strengths. He warns these protozoa of the coccidia organisms will invade into the cells that line the intestine and then destroy the intestine as they multiply. But sometimes these protozoa do not show up in a fecal float, so it is important to not rule out coccidiosis if that is what is suspected, and the fecal float is negative.

White adds most calves will have coccidia organisms in their systems already.

Larson explains it is common for most mammals to have these organisms present in their systems, and the coccidia are specific to animal species. So, a high number of these organisms would confidently indicate coccidiosis, but smaller numbers should not be looked over either.

Larson and White both agree coccidiosis seems to be the issue with this ranch’s case, so the next item to address is where or how the calves contract it.

Control and Prevention

“They had it themselves — it’s not that they got it from somebody else necessarily,” Larson explains.

But he notes cattle can still get sick if they encounter calves carrying a coccidia species they haven’t been exposed to.

Young cattle like these are more susceptible to coccidia protozoa because they haven’t had time to build an immunity to them like older cattle would. However, there are a variety of populations of coccidia, so they cannot build an immunity to all types.

“There’s some challenges there keeping everybody on track nutritionally, and I’m mixing cattle from different sources, which probably means they are bringing in different types of coccidia,” Larson says.

White adds coccidia can be spread by fecal or oral contamination, and this setting is ideal for it. However, he also mentions their ration has an ionophore in it that should help control the contamination.

Rumensin or Bovitech are common ionophore products that provide control, but Larson says we should think of them as ways to control the multiplication of organisms. If cattle are at high levels of protozoa already, these additives are ineffective. But they are a crucial part of control and prevention.

For early precautions, Larson recommends feeding ionophore products like Decoquinate or Amprolium as they, “will do a better job of killing those organisms at other stages in the life cycle.”

Once calves are settled from weaning and their stress levels decrease, then they can be switched to other ionophores in their daily rations.

Larson says these treatments can be administered in feed or water, but it is often better to treat individual animals. Then, the whole group can be started on the ionophores for further prevention.

Managing environments and their conditions and limiting nutritional and weaning stress is also beneficial in the prevention of coccidiosis.

Larson reminds producers: “It takes consistent attention to the details to try to keep these problems at bay.”

Seeing the Whole Elephant: Systems Thinking and Animal Health

Mon, 24 Nov 2025 22:19:50 GMT

We all know the ancient parable of the blind men and the elephant: each man touches a different part of the elephant and becomes convinced he knows the whole animal. One feels the trunk and declares it a snake, another the leg and insists it’s a tree. Each observation is accurate, but each conclusion is deeply incomplete.

Veterinary medicine often falls into the same trap, not because of a lack of care but because of training to look closely. In a world where disease emerges from the interactions of nutrition, immunity, environment, behavior and management, the old parable reminds us the truth isn’t found in any single part. It’s found in the relationships between them.

Why Looking Closely Isn’t Enough

Pattern recognition is one of our greatest strengths. You learn to see classic presentations and link them with a diagnosis. For example, ketosis in a fresh cow or BRD in a calf with a cough.

But disease rarely lives in one organ system or one management practice. A narrow focus can deceive us. We might fixate on the ‘tusk’ because it looks sharp and obvious, while missing the constellation of forces actually driving the animal’s response.

Examples crop up everywhere:

A dairy lameness problem blamed solely on digital dermatitis, when the root cause is chronic wet bedding, poor ventilation and subtle changes in stocking density.
A calf barn respiratory outbreak attributed to infectious bovine rhinotracheitis, when the real sequence of events begins with colostrum quality, followed by fluctuating ventilation, then a weather front that pushes calves over the edge.
A feedlot dip in performance linked solely to a ration change, when heat stress, water access, bunk competition and handling stress created a cascade of interacting pressures.

Each diagnosis contains a piece of truth, but each is incomplete when treated in isolation.

Systems Thinking: Looking Between the Parts

Systems thinking is the discipline of understanding how elements interact to produce outcomes. It challenges us to stop asking what caused this and start asking how these factors combined to create this situation.

Dr. Brian Vander Ley of the University of Nebraska-Lincoln recently spoke on the topic.

“Systems thinking is actually a derivative of a field called ‘systems dynamics,’ which is a highly mathematical modeling field that’s used to predict the behavior of systems based on components in the system and relationships,” Vander Ley explains. However, systems thinking takes out the math component. “It’s a set of tools, processes and principles that enable us to focus on the relationship between parts of the system and not just some of the parts themselves.”

A system isn’t just a list of components. It is:

The feedback loops between nutrition and immunity
The way ventilation interacts with pathogen load
How handler behavior influences stress physiology
How management timing affects microbial dynamics
How one week’s decisions become the next month’s disease patterns

The iceberg analogy fits here too: What we see in the cow is only a small fraction of what’s really happening. The larger drivers of disease sit below the surface and remain invisible unless we deliberately go looking for them.

The heart of systems thinking is recognizing that diseases are rarely linear. They are networked. They emerge not from one factor but from several interacting simultaneously, sometimes amplifying, sometimes buffering each other.

In other words, the elephant is not just trunk + tusk + leg + ear. The elephant is the relationships that connect those parts into a living organism.

The Veterinarian as a Systems Navigator

Veterinarians already intuitively use systems thinking. You’re constantly piecing together physiology, environment and behavior. The challenge is doing it intentionally rather than incidentally.

This means asking broader questions:

Where did the system fail and why?
What feedback loops are reinforcing the problem?
Which variables are upstream versus downstream?
What invisible pressures are shaping what I can see?
What happens if one part of the system changes?

When we ask these questions, we stop thinking like the blind men — competing diagnoses based on isolated observations — and start thinking like systems analysts, integrating multiple perspectives into a coherent picture.

This is also dependent on communication within the animal care team.

“Communicating about it is really important, because we are really sure about our own experiences. When I go out and collect data with my own hands and my own eyes, I’m very confident in that data, and when I see information that’s very different, I tend to disregard that information,” Vander Ley says. “We want to engage in a kind of communication that allows us to appreciate that we’ve got different pieces of the elephant in hand.”

Having an open dialogue between owners, producers, veterinarians and academics allows for a broadened perspective for understanding what the problem is.

Case Example: Reframing a ‘Simple’ Mastitis Problem

Take a herd with climbing somatic cell count and increased clinical mastitis cases. A parts-focused approach might look at:

Teat-end condition
Milking protocols
Bedding
Culture results

A systems approach goes further:

How has cow flow changed through the parlor?
Are fresh cows being mixed too early?
Has ration moisture affected rumen health and lying time?
Are staff changes altering consistency in milking prep?
Has heat stress reduced rumination and immune resilience?
Are equipment cleaning routines changing due to workload?

Suddenly, the rising cell counts are no longer an udder health issue but a system problem — a signal, not a cause.

Stepping Back to See the Elephant

The parable of the blind men isn’t merely about limited perspectives; it’s about the illusion of certainty that comes from seeing only one piece of a larger, interconnected whole.

Veterinarians do some of their best work up close: palpating, listening to internal sounds, evaluating subtle signs. But the greatest diagnostic breakthroughs often come when we deliberately widen our view and consider not just the parts but the interplay between them.

Systems thinking doesn’t replace traditional diagnostic skills, it evaluates them. It turns isolated observations into meaningful patterns. It turns symptoms into stories. It turns disease into a map we can navigate instead of a puzzle we must solve.

In the end, seeing the ‘elephant’ means seeing not just the cow or the herd but the interconnected ecosystem that shapes every outcome.

Turn Milk Data Into An Early Diagnosis

Tue, 18 Nov 2025 14:23:58 GMT

Modern dairy operations generate an extraordinary amount of information from every milking, yet some of the most valuable health indicators are hiding in plain sight inside the milk meter. For veterinarians, these data streams offer one of the earliest, most reliable windows into emerging disease, often days before clinical signs appear.

“Most people forget about milk production,” says Dr. Aurora Villarroel of Athyr Vet, a dairy herd health consulting company. “The milking machine is actually your best biosensor. It’s your most important one and most people ignore it.”

While different monitoring systems may present data in different ways, interpreting milk yield, component and conductivity data can allow for clinicians to detect subclinical disorders with greater precision than traditional observation alone. As technology becomes more integrated into routine dairy management, the veterinarian’s role increasingly centers on interpreting these numbers, guiding producers toward timely responses and translating these metrics into practical on-farm outcomes.

Milk Yield Deviations

Milk yield is often the first and most sensitive indicator that something is wrong. A cow that deviates from her expected production curve, given lactation history, or a fresh cow whose production isn’t increasing as it should needs to be looked at.

Villarroel advises putting together the milk yield data from a given cow’s lactation history to assist in spotting any irregularities.

“Some of the software will allow you to superimpose all of the lactations of the same cow,” Villarroel says. “What you’re going to see is that the lactations have the same shape. It’s genetic, but it’s a different shape in each cow.”

By comparing the life lactation history of an animal, you can determine whether any observed shifts in milk yield are expected or out of the norm. Villarroel emphasizes the importance of zooming out to get the big picture. When you’re looking closely at two to three days of milking data, small changes in yield may seem insignificant; however, when you put these two to three days into context with a greater portion of the lactation, it may tell a different story.

Component Changes: Fat & Protein

Milk components add critical context to yield changes and help pinpoint specific metabolic disorders. Fat percentage often rises when a cow is metabolizing excessive body fat, making it one of the most consistent indicators of negative energy balance or subclinical ketosis. Conversely, milk protein tends to drop with decreased feed intake, rumen dysfunction or systemic illness. The fat-to-protein ratio (FPR) is particularly useful in transition cow monitoring: an elevated FPR may indicate an energy deficit.

If you’re evaluating whether a new nutrition program is working for your herd, consider using butter fat content and animal activity as indicators.

“The milk yield takes a while still to change, but butter fat and resting time are the first two things that change almost immediately,” Vilarroel says.

Milk Conductivity

Changes in milk conductivity are also useful as an indicator of udder health and useful for the diagnosis of mastitis. Conductivity measures the salt content of the milk, which is dependent on the permeability of blood vessels, or damage to the blood-milk barrier. Because this shift can occur before visible changes in milk or the udder, conductivity is one of the earliest warning signs of mastitis at the quarter level.

“When the conductivity goes up, there’s inflammation in the udder. Something is going on in the udder so that there’s more salt in the milk,” Villarroel explains. “Conductivity changes are a precursor to somatic cell count changes.”

Somatic cell count patterns offer a complementary perspective, highlighting cows that are experiencing subclinical infections. Reviewing somatic cell count trends on a per-cow and per-lactation basis can help identify management decisions that may be affecting udder health.

Put Milk Measurements Together

While each milk metric offers useful information on its own, their real power emerges when they are interpreted together. No single measurement is diagnostic, but patterns across multiple indicators can be used to identify cattle who need to be checked on.

“How do you check every single thing in a cow every single day?” Villarroel says. “Guess what? You can. You just need to know how to interpret it.”

A cow showing modest yield drop may simply be responding to heat stress or social disruption; however, a yield drop paired with an elevated FPR suggests negative energy balance or early ketosis. Similarly, a spike conductivity alone may reflect milking irregularities, but when it appears alongside a somatic cell increase, the probability of mastitis increases.

Transforming milk data into meaningful herd health outcomes requires consistent workflows that integrate monitoring, diagnosis and communication. This may start with a focus on high-risk groups (transition cows, fresh cows, high-somatic cell count repeat offenders) and building structured review protocols around them. At the herd level, data driven insights can shape broader management decisions. Rising conductivity across a pen may indicate bedding or hygiene issues, while recurrent FPR spikes may indicate ration inconsistencies. By combining milk measurements into a cohesive health signal, you can move from reactive case management to proactive herd surveillance — catching problems early when they are the most treatable.

5 Sampling Tips for Improved Diagnostics

Tue, 07 Oct 2025 13:15:46 GMT

You’d be hard-pressed to find a veterinarian or producer who hasn’t been frustrated with a diagnostic result. When it comes to herd health, good diagnostics are like detective work, but even the best tests can’t help if the wrong evidence is collected.

Sampling isn’t just grabbing what’s handy; it’s a deliberate process that links a clear question to the right animal, tissue and timing. Getting that process right saves money, reduces frustration and leads to faster, more confident decisions.

Here are five practical ways producers and veterinarians can work together to improve sample collection on the farm so that every diagnostic submission counts.

1. Start With the Right Question

Before taking a single sample, step back and ask: What do we want to know?

“Your diagnostic question really drives everything from sample selection to animal selection,” says Drew Magstadt of the Iowa State University Diagnostic lab. “If we don’t define the problem — What are you seeing? What’s going on? Why are you calling the lab? — we can’t really formulate a differential diagnosis list that we ask a diagnostic question.”

Taking samples “just to see what turns up” often leads to inconclusive results and wasted effort.

Field tip: Include your diagnostic question on your submission form. This helps the lab choose the best testing pathway and increases your chances of getting actionable answers.

2. Choose the Right Animals To Sample

When disease strikes, not all animals tell the same story. Aim to collect from animals showing early or typical clinical signs, not just those that are terminally ill.

“The answer isn’t always ‘the dead one that’s in front of us,’” stresses Magstadt. “Focus on acutely affected, untreated and representative animals.”

For herd investigations, sample several animals within the same group or age class to capture variation. In some cases, sampling a few seemingly healthy herdmates could provide valuable comparison data. Sampling only the worst looking survivors or those already treated with antibiotics could mask the cause of disease or send you down the wrong diagnostic path.

Field tip: For mortality events, select the freshest animals possible for necropsy. Early submissions preserve tissue integrity and increase the odds of a meaningful result.

3. Take the Correct Sample Type and Handle It Properly

Even the perfect sample loses its value if it degrades before reaching the lab. The sample type, container and preservation method matter just as much as the collection itself. Each diagnostic test has its own validated sample requirements. Using the wrong media, failing to chill samples or letting tissues autolyze can render tests useless.

On an episode of “ DocTalk ,” Dan Thompson highlighted some considerations for sample collection: “Being able to take the size of the sample from the right spot so that you have healthy tissue next to diseased tissue for histology. Getting the proper sample so that if you’re going to isolate pathogens you can. Whether you [need] fixed or fresh tissue. You need to work with your veterinarian who will know exactly what [you] want to have.”

A few extra minutes of planning can save days of waiting for a “sample unsatisfactory” call.

Field tip: Check your diagnostic lab’s sampling guide before collection and label everything clearly (animal ID, tissue, date).

4. Record Good Clinical and Herd Information

Providing accurate clinical histories and observations helps diagnosticians interpret findings in context. Include information such as onset and duration of illness, number of animals affected, treatments used, feed changes and vaccination history. Consider including photos if applicable.

This kind of supporting information allows labs to match findings with disease patterns and may even prompt recommendations for additional or alternative testing.

The Beef Cattle Research Council has put together a great resource for anyone interested in leveling up their animal health record-keeping.

Field tip: Use your herd health software to standardize the process. The more detail you include, the better.

5. Sample Early and Sometimes More Than Once

Timing matters. By the time a sick animal has been treated, recovered or died, diagnostic clues may have vanished.

Magstadt stressed that it’s possible to get a negative diagnostic test in a positive animal based on when a sample was taken. You must take into account “the timing of disease, when we would expect large amounts of the pathogen to be there, when we wouldn’t, and the different pathogens [involved].”

Whenever possible, collect samples early in the course of disease — ideally before antimicrobial or anti-inflammatory treatment. For diseases with intermittent shedding, repeat sampling over several days increases detection odds. Also consider whether pooled or composite sampling might make sense for your diagnostic goals.

Field tip: Keep sampling supplies ready on-farm so you can act immediately when new cases appear. Rapid responses can mean the difference between inconclusive results and a valuable diagnosis.

How Can We Improve Chuteside Diagnostics?

Mon, 29 Sep 2025 16:32:04 GMT

When a coughing steer steps into the chute, you might only have a few moments to decide if this animal is likely to recover with treatment or will further intervention be futile. The difference matters, not only for the animal’s welfare but for treatment costs, labor and antimicrobial stewardship.

Dr. Brad White of Kansas State University has been working on ways to make those chuteside decisions more accurate. His recent presentation at the 2025 American Association of Bovine Practitioners Annual Conference laid out new tools and technologies that could be incorporated into everyday feedlot medicine.

“[The] goal of chuteside testing is not just diagnostics, it’s which bucket can I put [the animal] in,” White says. “What if I could change the likelihood, or I had a diagnostic tool that would give me a better prognosis, and I had more chance of putting the ones that were going to live into this bucket and more chance of putting the ones that won’t live into the other bucket.”

White suggests thinking of chuteside decision-making using the Chuteside Ps:

Precision: How accurately can we distinguish specific disease syndromes that might display similar clinical signs?
Prescription: What treatment is appropriate based on the specific disease status?
Psychology: How do our own biases shape decisions under pressure?
Prioritization: Which cases should be segregated to provide additional therapeutic and management procedures to a smaller subset?
Prognosis: What is the animal’s likelihood of recovery?

Why this matters

Misclassification can have real economic consequences. In a study evaluating over 3,800 calves diagnosed with acute interstitial pneumonia (AIP) chuteside, 42% of treated animals finished the feeding phase and showed positive return, while 25% were culled and 33% died.

On average, estimated net returns were positive for cattle that finished with their cohort, even after multiple treatments ($98 for one treatment, $85 for two, and $46 for three). Animals that were culled after one to three treatments averaged negative $900 of net returns, meaning that in all cases, it would have been better to keep the calf then cull it.

While most veterinarians might consider AIP a death sentence diagnosis for cattle, this work demonstrates that is not always the case.

Clinician bias cannot be ignored when considering diagnosis. Under pressure, veterinarians and feedlot crews might over-diagnose or lean on familiar categories.

For example, AIP is most frequently diagnosed at 80 to 140 days on feed; however, necropsy evaluations have shown a more even distribution of cases throughout the feeding phase.

Chuteside technologies might be useful to incorporate in an effort to avoid inherent human biases.

Chuteside Tools

There are several tools under investigation that could be useful for chuteside antemortem cattle assessment. Three that have shown some promise are:

Cardiac troponin I: Elevated levels have been shown to be highly specific for poor outcomes in bovine respiratory disease cases, though sensitivity is limited. Animals testing positive have a much lower likelihood of successful recovery.

Mucous membrane assessment: Animals with abnormal mucous membranes have been found less likely to finish. However, this testing had low sensitivity and high specificity.

Targeted thoracic ultrasound: Can be used to reveal interstitial changes that are not apparent on a physical exam, helping differentiate acute from chronic respiratory conditions.

Along with these, predictive models using multiple diagnostic inputs have shown promise for determining case outcomes. However, these are hard to use quickly chuteside.

“There’s no single metric that’s going to get us there,” White advises. “Our thought process is that we’re likely going to have to combine [metrics]. Part of the trick is figuring out which places to apply them.”

Practical Challenges

Integrating new diagnostics is not without hurdles. Equipment cost, chuteside practicality and training all matter. Time pressures in the chute are real, and not every feedlot crew is ready to adopt ultrasound or biochemical assays into their routine.

Field validation is another concern. Tools that work in controlled research settings might not always translate seamlessly to the dusty, high-pressure environment of a feedlot. Veterinarians must balance the potential gains with the realities of implementation.

Looking Ahead

White hopes that each veterinarian and producer asks themselves these important questions:

“How can I be more precise with these cases, and how can I use prognosis to prioritize them based on my management decisions? We’ve got many of the same classes of treatments and therapies that we’ve had for years; how can we make sure that we’re using them at the right place and the right time?”

Texas A&M Researchers Study Diet’s Impact On Salmonella Prevalence In Cattle

Mon, 25 Aug 2025 15:29:16 GMT

Salmonella is one of the leading causes of foodborne illnesses in the U.S., according to the Centers for Disease Control and Prevention, and can spread to people from a variety of foods, including beef. Understanding how and why cattle become infected with Salmonella is an important part of fighting this major public health concern.

Researchers at the Texas A&M College of Veterinary Medicine and Biomedical Sciences (VMBS) are addressing this problem from a new angle by studying how diet and feeding schedule impact Salmonella infections in cattle.

Their recent study , published in the American Society for Microbiology’s Microbiology Spectrum journal, found that high-starch diets can potentially lower Salmonella prevalence in cattle, especially within the lymph nodes — organs that are often embedded in fat trims included in ground beef products.

“Lymph nodes may be present in fat trimmings that are used to balance lean-to-fat ratios in ground beef products,” says Yesica Botero, a fourth-year biomedical sciences doctorate student. “This is a food safety concern because Salmonella can hide inside lymph nodes, where surface cleaning or treatments do not reach. As a result, it can still be present in ground beef.”

Feedyard cattle are typically fed a high-energy, grain-based diet designed to promote rapid growth and efficient weight gain.

Understanding the role that a high-starch diet potentially plays in reducing Salmonella prevalence could have major impacts on the beef cattle industry, providing ranchers with new options for controlling the spread of bacteria within their herds.

Taking A New Approach

The Texas A&M project was designed to study feedlot cattle that Dr. Kendall Samuelson, from West Texas A&M University, was examining in a separate project to see whether high-starch diets and feeding schedules impact liver abscess formation.

“We aimed to understand the factors that contribute to the presence and distribution of salmonella in feedlot cattle,” said Dr. Gizem Levent , a VMBS assistant professor in the Department of Veterinary Integrative Biosciences . “There aren’t many studies focusing on understanding how diet and management changes impact Salmonella.”

Botero and Levent took samples of feces, hides, lymph nodes and soil from Samuelson’s cattle pens over a period of more than seven months. They found that while there was little difference in Salmonella populations between cattle with scheduled versus erratic feedings, the level of starch in the diet made a notable impact.

“We saw a reduction in Salmonella, especially in the lymph nodes, when cattle were fed a high-starch diet,” Botero says. “High-starch diets typically cause a lower pH in the rumen, which may be what reduces Salmonella prevalence in the gastrointestinal tract and, subsequently, in lymph nodes.

“Findings from Dr. Samuelson’s original study suggested that high-starch diets may also correlate with a higher incidence of liver abscesses,” she says. “This is something we would like to explore further in upcoming studies by testing different starch concentrations in the diet to find one that does not harm cattle health — such as by increasing the risk of liver abscesses — but still helps lower Salmonella levels.”

Continuing The Investigation

In addition to studying how different levels of starch impact liver abscesses and Salmonella, Levent and Botero are planning to dive even deeper into the data to study the specific serotypes, or genetic profiles of Salmonella, observed in their samples.

“We want to do a follow-up study with more in-depth analysis of the dynamics of the Salmonella population,” Botero says. “By looking at the genetic profiles, we can better understand which serotypes are present, how they might respond to antibiotics, and whether they carry genes that make them more likely to survive or spread in the environment.”

Fortunately, what they have seen so far from the feedlot samples does not indicate a high presence of Salmonella or serotypes resistant to antibiotics.

“The overall Salmonella population found was not resistant to antibiotics of public health concern, which is good news for public health,” Levent said. “But we will definitely keep screening for resistance so that we can better understand what makes resistant populations exist in the environment.”

Bull Tests Positive for Brucellosis: Herd Quarantined and Investigation Continues

Thu, 21 Aug 2025 16:09:19 GMT

On Friday, August 15, the Montana Department of Livestock (MDOL) received confirmation that an animal from a Beaverhead County herd within Montana’s Designated Surveillance Area (DSA) tested positive for brucellosis.

According to a press release , the herd has been placed under quarantine pending the completion of an epidemiological investigation.

The positive bull was identified as a brucellosis suspect during required testing at a livestock market in late July. The animal was euthanized and taken for necropsy at the Montana Veterinary Diagnostic Laboratory where tissues were collected and sent to the USDA National Veterinary Services Laboratory (NVSL) in Ames, Iowa, for confirmatory testing. NVSL was able to grow the Brucella abortus organism from one of the lymph nodes collected from the animal.

The disease investigation will include testing and tracing of animal contacts and movements to ensure the disease is not present in other livestock herds. MDOL will work with the affected operation to minimize the impact of this diagnosis by conducting a tailored and focused investigation.

Montana’s Designated Surveillance Area (DSA)

(Montana Department of Livestock)

Montana’s DSA exists due to the risk of disease spillover from infected wildlife in the Greater Yellowstone Area (GYA). Program testing requirements help ensure cases of brucellosis in livestock are detected before animals leave the DSA. Successful early detection provides confidence to Montana’s trading partners that any Montana cattle they may receive are brucellosis free. Brucellosis causes reproductive issues in livestock including abortions, still births and neonatal mortalities.

“While detections of brucellosis are a hardship on operations, this detection is still a reflection of the success of our state brucellosis program,” says Dr. Brenee Peterson, MDOL veterinarian. “Through the work of DSA producers and local veterinarians, we continue to detect the disease early and prevent the export of a brucellosis-infected animal to one of our trading partners.”

Previous Brucellosis Detection

This herd is the 14^th brucellosis-affected herd confirmed in Montana since the implementation of the DSA in 2010. The most recent detection was within the DSA in Madison County in April 2023. While the source of infection for this latest infected bull has not yet been determined, DNA genotyping and epidemiological investigations have concluded the previous 13 infections came from wild elk. Prior investigations have also confirmed brucellosis has not spread to neighboring herds through fence-line contact.

What is Brucellosis?

According to USDA’s Animal and Plant Health Inspection Service (AHIS) brucellosis (also known as contagious abortion or Bang’s disease) is a costly disease of livestock and wildlife. It is caused by a group of bacteria in the genus Brucella. The disease has significant consequences for animal health, public health and international trade.

Brucellosis occurs mainly in cattle, bison and swine, but can affect other animals (cervids, goats, sheep and horses) as well as people.

In cattle and bison, the bacteria of concern is Brucella abortus. It has been present in the U.S. since the 1930s. A longstanding national eradication program mostly eliminated the disease in U.S. cattle. Today, only occasional spillover cases occur in cattle and other livestock near the GYA. Wild bison and elk in the GYA are the last remaining reservoir of this disease in the U.S.

According to the APHIS website , when signs do appear, they’re most obvious in pregnant animals. Here’s what to look for:

Abortion (usually at five to seven months of pregnancy)
Birth of weak, unhealthy calves
Decreased milk production
Weight loss
Poor conception rates or infertility
Retained afterbirths with resulting uterine infections
Enlarged, arthritic joints (occasionally)

“Appearance alone isn’t an effective way to detect brucellosis,” according to the website. “Infected animals may appear healthy, even during pregnancy. However, they can still harbor and spread infectious bacteria and serve as dangerous sources of infection.”

Producers or owners who suspect an animal disease should contact their veterinarian to evaluate the animal or herd.

Three Strategies to Prevent Weaning Health Woes

Mon, 04 Aug 2025 15:42:13 GMT

Careful planning and management are critical to maintaining animal health at weaning. Before starting the weaning process, the first step is making sure the calf’s immune system is ready for the stress of being separated from its mother.

“I encourage producers to work with their practicing veterinarian and review their herd health protocols for weaning in advance of when they start the weaning process,” says Jason Warner, Kansas State University Extension cow-calf specialist. “Have an annual conversation and a plan put together that can be adjusted each year.”

Megan Van Emon, Montana State University Extension beef cattle specialist, says the goal should be to strengthen the calves’ immune systems before they face the challenges of separation from their mothers, potential transportation and new environments.

“Proper vaccination can help reduce health risks during this critical transition period,” she summarizes.

Warner, Van Emon along with John Hall, University of Idaho Extension beef specialist, and Ron Lemenager, Purdue University beef specialist, share these three strategies to help keep calves healthy at weaning.

1. Develop a Vaccination Strategy to Boost Immunity.

“One of the first things I suggest is a good vaccination program that a producer works on with their veterinarian,” Hall says. “The earlier you can reach out to your vet, the better; just to get those vaccines lined up. Make sure they have them in stock and ready to go for you.”

It takes 10 to 14 days for a calf’s immune system to sufficiently respond to a vaccine, so immunizations should ideally occur two or three weeks ahead of weaning. The specialists explain vaccinating calves for the first time at weaning is too late, as it doesn’t allow sufficient time for the vaccine to work before introducing calves to increased exposure risk.

Lemenager recommends a minimum of two vaccination rounds for weaned calves — one before weaning and then the second at weaning.

Hall reminds producers to review the vaccination protocols and be sure to booster if needed.

2. Don’t Combine Stressful Procedures.

Lemenager stresses the importance of not combining weaning with other stressful events such as castration and dehorning. He suggests castration and dehorning at branding or earlier, if possible, to reduce stress.

3. Observe for Illness Indicators.

“It’s that seven to 10 days to two weeks after weaning that we’re going to start seeing any kind of health issues,” Lemenager says,

It is important to monitor and watch for early signs of health issues, including:

Water and feed intake
Lemenager says dehydration is a common issue that can cascade into other health issues.
Activity level
Eye brightness
Ear position
Hall says to watch for droopy ears and depressed-looking calves.
Nasal discharge
Breathing quality and speed
Coughing
Manure
Hall says to watch for manure inconsistency as well as for signs of coccidiosis (blood-tinged)
Overall energy and movement

Lemenager explains if you have a weaned calf with any of the indicators it is a good strategy to take its temperature and then work with your veterinarian or herd health provider to develop a strategy and come up with the first line of defense before a potential outbreak occurs.

Get BQA Certified

Hall reminds producers about the importance of the Beef Quality Assurance program and encourages all producers and their employees to get BQA trained and certified .

The BQA program’s mission is to guide producers toward continuous improvement using science-based production practices that assure cattle well-being, beef quality and safety. The program provides cattle producers with the resources to enable continuous improvement with the mindset of doing things the right way at the right time.

“When vaccinating or working cattle, be sure to follow BQA procedures,” Hall says. “Including proper injection sites, never mixing two different vaccines in the same syringe, using the proper sized needle and changing them often, keeping vaccines in a cooler and out of the sun (proper vaccine handling).”

Check out the BQA Field Guide for a quick reference to information.

Implementing the strategies suggested by the Extension specialists can significantly improve calf health during the weaning transition, resulting in better performance and increased profitability.

Your Next Read: Key Nutrition Strategies for a Successful Weaning

Don’t Waste Feed: Let Manure Scores Guide Cattle Nutrition

Mon, 04 Aug 2025 13:41:57 GMT

Evaluating cattle productivity often focuses on common benchmarks such as body condition, weight and feed consumption. Yet, there’s another informative — and sometimes ignored — performance indicator in plain sight: manure.

What comes out of the back end of your cattle can tell you a lot about your nutrition program. By utilizing a manure scoring tool, you can analyze your cattle’s manure and better understand how well the rumen is working to ensure your nutrition dollars are being used by the cow and not just passing through into their manure.

“Think of manure scores as a short-term report card on how the diet’s doing in the rumen,” says Ted Perry, Purina Animal Nutrition cattle nutritionist. “By scoring manure on the 1-5 scale, you can gain insight into the rumen environment, optimize your nutrition program and get more out of your feed resources.”

What do the manure scores look like and mean?

(Purina Animal Nutrition)

Manure score 1: The manure is more liquid than solid, with a cream soup consistency and possible gray color. The rumen isn’t functioning correctly, and what’s passing through is essentially water. This can also be an indication of acidosis and rumen upset. It is most commonly seen in feedlot diets.

(Purina Animal Nutrition)

Manure score 2: Manure doesn’t stack up properly. The manure pat is usually less than 1 inch thick and relatively runny or nearly liquid-like. The color will generally be the normal manure brown, typically experienced when forages are lush in the spring.

(Purina Animal Nutrition)

Manure score 3: This is the ideal manure score to aim for year-round in your cow herd. It has a normal manure pat form and will be relatively firm and retain its shape.

(Purina Animal Nutrition)

Manure score 4: The manure pat is thick and becomes more profound, yet it is not stacking. Rumen is not balanced for protein, carbohydrates and fiber degradability. It tends to happen when corn is added to the diet, and you’ll see undigested corn particles in the manure.

(Purina Animal Nutrition)

Manure score 5: The manure pat is firm and stacks over 2 inches high. It can also resemble horse manure in its look because undegraded fiber passes through the rumen. You can break open the manure and see the fiber.

How can you improve manure scores?

Manure score 1 requires the most significant diet change and will need a lot of fiber, usually in the form of hay.

“You’ll also want to work with a nutritionist to adjust the diet properly when the manure score is so low,” Perry says. “If the manure score is 2, ensure a quality mineral balanced for trace minerals is available, along with providing any supplemental fiber.”

When scores are higher (4 and 5), supplementation can bring the rumen back in balance by increasing forage digestibility. Using a cooked supplement like a tub or block helps regulate the manure score by feeding the rumen microbes appropriate amounts of starch, protein, vitamins and minerals.

“If you feed the rumen microbes properly, you’ll get better forage digestion,” Perry says. “For instance, it’s not uncommon to see cows grazing corn stalks with protein tubs having a manure score of 3 because the rumen microbes have been fed right.”

To maintain an ideal manure score of 3, adjust your supplementation and mineral as forages change.

“Forage quality constantly shifts throughout the year, so your nutrition program must also shift,” Perry says. “Adjusting the nutrition program based on manure score helps keep the cow herd in optimum body condition score (BCS).”

When should you gather manure scores?

Manure scores can be gathered throughout the year. A good time to utilize this tool is in tandem with body condition scoring to get an even better idea of how your nutrition program is working. If you currently work with a nutritionist to help body condition score your herd, they can also assist you with manure scores.

“It’s also a good idea to check manure scores whenever there’s a diet change,” Perry explains. “If you’ve moved the herd from one type of forage to a new one, like dormant native grass in late winter to wheat pasture, there will be a difference in the manure.”

Similarly, if you’re grazing pasture or feeding hay and consistently see a manure score of 5, it’s time to make a change with some supplementation and minerals. Three to four days after making a diet change is the ideal time to reevaluate manure scores because the rumen has had enough time to adjust.

“Much like body condition scoring, manure scoring can quickly tell you how your herd is performing and help you make important nutrition decisions,” Perry summarizes. “Incorporating this tool into your regular management routine can give you valuable insights to ensure your nutrition program is as efficient and effective as possible.”

Your Next Read: Key Nutrition Strategies for a Successful Weaning

Risk Factors Associated with BRD in Preweaned Calves

Fri, 01 Aug 2025 13:55:33 GMT

A well-managed Midwest cow-calf ranch has a problem with respiratory disease in its preweaned calves. They retain ownership, artificially inseminate and manage everything well according to Kansas State Veterinarian Brad White.

During a recent “ Bovine Science with BCI ” podcast, Kansas State University veterinarians Brad White and Bob Larson explore potential causes for bovine respiratory disease (BRD) in preweaned calves and how to mitigate the problem. White says discussing how to deal with preweaning BRD with producers can be frustrating because clear answers are not always possible.

Larson explains typical BRD preweaning symptoms for a spring calving herd will show up midsummer when the calves are about 4 months of age or a little older and still nursing on pasture.

“We could see 15% to 20% of the calves display symptoms,” Larson explains. “What we’re looking for is kind of typical, depressed, their heads down, maybe rapid breathing, those types of things. They’re not really being aggressive with their suckling or eating or anything.”

Larson reminds producers this fits the same description of respiratory disease in older calves. He says, likewise, some death loss can occur.

“Probably the most common what I see is up to 20% of the calves are affected, and from among those that we treat, you get just a few deaths,” he says.

Research Findings

Larson explains a recent K-State research project regarding BRD. Research surveys of more than 400 herds revealed several key insights. Several potential risk factors were identified that could contribute to preweaning respiratory disease:

Artificial Insemination (AI) and Synchronization. Gathering cattle for AI can increase disease transmission and changing pasture dynamics and increasing close contact among calves.
Management Practices. If cattle are managed using intensive grazing strategies or creep feeding these practices that alter normal grazing patterns and increase calf interaction and thus disease transmission.
External Exposure. Grafting calves into a herd, grazing stocker cattle in the same pasture or any introduction of outside animals can be a potential risk factor.
Immunological Factors. Declining maternal antibody protection at 3 to 5 months of age. Front-loaded calving seasons creating a cohort of calves vulnerable at the same time.

Larson stresses this is speculation because many herds do those types of practices and do not have a summer pneumonia problem.

“So, it’s not a smoking gun that if you do these practices, you’ll run into summer pneumonia,” he summarizes. “It’s just that we saw a little bit higher risk in those herds that did some of these, again, kind of changing the normal grazing distribution and pattern that calves interacted.”

Larson and White share several prevention and management strategies:

Maintain strict biosecurity
Isolate grafted or new calves
Avoid commingling different cattle groups
Ensure good nutrition and sanitation
Consider vaccination protocols carefully

During the podcast , the researchers highlight the complexity of preweaning BRD, noting that no single factor guarantees prevention. Each herd requires a tailored approach and working closely with a veterinarian to understand specific risk factors.

The primary takeaway is that while preweaning BRD is frustrating and not entirely predictable, producers can mitigate risks through careful management, biosecurity and proactive health strategies. Good, foundational practices such as maintaining cow health, providing a sanitary environment and monitoring the herd remain the most critical components of prevention.

Producers experiencing recurring issues should reassess their management practices, vaccination protocols and herd dynamics to reduce the likelihood of preweaning respiratory disease outbreaks.

There’s a Lot of Info in That Little TSU

Tue, 29 Jul 2025 17:06:26 GMT

“The sky’s the limit if you have that sample,” says Jim Butcher, a Simmental seedstock producer from Lewistown, Mont.

He’s talking about all the things you can learn about the genetic potential of your cattle that is contained in a tissue sampling unit (TSU). The genomic information you get from each sample can, collectively and individually, help you more quickly move your herd’s genetic progress forward in an intentional, science-assisted direction.

There’s lots of info in that little vial.

(Allflex)

For commercial cow-calf producers, submitting the DNA sample in a TSU will return a scoresheet on each animal ‘s genetic merit for different indexes and specific traits, says Leoma Donsbach, owner and founder of Data Genie, LLC.

She calls herself a data accountant, helping customers attach the data on their operation to their record-keeping system. She says almost all her customers use TSUs to collect DNA and obtain genomic data.

Genomics are becoming more and more popular with commercial beef producers, she says.

“For replacement females, the ability to have a snapshot of that female’s genetic potential leads to increased confidence in keeping that heifer. You can say, ‘This heifer is more likely to be here until age six or seven by looking at her stayability metrics.’”

Say, for example, you’ve done your visual appraisal and picked 50 heifers as potential replacements, but you only need to keep 40. Visually, those heifers are very similar. But genetically, they could be very different, depending on what genes they received from their parents.

That’s where the TSUs and the genomic data they provide come in. First, test all 50 replacement candidates.

“Then breed them and find out which ones are bred,” she says. Even if everything went right, that still leaves some extras. “You can go back and use the genomic data to select the traits you want and/or use a maternal or terminal index to make those final decisions. You use it like comparing genomically enhanced EPDs when buying bulls.”

Beyond replacement selection, you can extrapolate the DNA data on your heifers when marketing your steers, she says. “On average, your steers will have similar genetics to your heifers. That information may add to their sale price.”

Then There Are The Bulls

Just like heifers, bulls can be full siblings and still be remarkably different in their genetic makeup.

“We’re great phenotype collectors of birth weights, weaning weights, all that,” Butcher says. “But you really don’t know what you have until you know what genes that particular animal picked up.”

When seedstock producers send in a TSU, they get back genomically enhanced EPDs. That, Butcher says, allows him to supply more accurate information about young bulls for his customers and help them make the best bull-buying decisions they can within their budget.

Indeed, not every bull is suited for every ranch. Studying the genomically enhanced EPDs gives you greater confidence in the true genetic potential of young bulls.

“You lessen the probabilities that you’re buying an animal that won’t help you move your program forward,” Butcher says.

Your Next Read: Building the Next Generation Cow Herd Using Genomic Testing

3 Livestock Skin Concerns to Watch For This Summer

Thu, 24 Jul 2025 20:11:02 GMT

Most livestock species have thicker skin than humans, but it’s still vulnerable to harsh summer conditions. Sun exposure, bacterial infections and increased activity of parasite-carrying insects can all take a toll on livestock skin.

Each year, the Texas A&M Veterinary Medical Diagnostic Laboratory (TVMDL) receives samples that reveal how sweltering summers affect livestock health. It’s essential to act promptly to prevent skin irritation from becoming painful and causing serious harm.

Effective diagnostic testing, paired with veterinary care, can help guide treatment and protect both animals and producers’ livelihoods.

Erin Edwards, DVM, MS, DACVP, veterinary pathologist at TVMDL, explains three common summer skin conditions to watch for in warm weather.

Photosensitization: Severe sunburn caused by toxic plants

Just like humans, animals can experience a fiery reaction to summer rays.

Photosensitization is a serious skin condition in cattle caused by a hazardous combination of certain plants and ultraviolet light.

(Texas A&M Veterinary Medical Diagnostic Laboratory)

“Effects of photosensitization are like a really severe sunburn,” Edwards says. “Livestock owners might see signs of redness, swelling and ulceration. Usually, the skin will start sloughing off, and it’s very uncomfortable for the animals.”

Primary photosensitization occurs when livestock become overly sensitive to sunlight after eating toxic plants containing the photosensitizing agent, phylloerythrin. The harmful compounds are concentrated in the skin, making it more susceptible to the sun’s rays.

“Burns are usually found on areas with less hair or pigmentation, like the nose or around the eyes,” Edwards says. “Lighter colored animals in general are usually more susceptible to burns.”

Secondary or hepatogenous photosensitization is the most common form of skin disorder. The prefix “hepato” comes from the Greek word “hepar,” meaning “liver.”

This form of photosensitization is caused by liver damage. Liver damage may result from a range of conditions, one of which is the consumption of toxic plants. When the liver fails to break down and eliminate substances like phylloerythrin, they begin to build up in the blood, increasing photosensitivity and causing the skin to react severely to sunlight.

In severe cases of photosensitization, skin, ear, lip and udder tissues may die and peel away. And secondary bacterial infections often occur after skin sloughing, leading to additional health concerns and delayed healing.

Furthermore, if livestock continue to consume toxic plants, liver damage could worsen and lead to death.

What to do if livestock show signs of sunburn or peeling:

Move affected animals to shade immediately.
Contact a veterinarian for diagnosis and care.
Remove liver-damaging and phototoxic plants such as Bishop’s weed and Largeleaf lantana from pastures.

To learn how to identify harmful plants, read Toxic Plants of Texas, written by veterinary and toxicology experts from The Texas A&M University System .

Rain rot: Crusty skin infections after wet weather

Rain rot , a disease caused by the bacterium Dermatophilus congolensis, is a skin infection that typically develops when pasture animals spend long hours in rainy conditions. Prolonged moisture softens the skin, allowing bacteria to enter — even without visible wounds.

Rain rot may appear to be a minor skin irritation at first, but it can quickly worsen without proper care.

Rain rot signs include:

Crusty, matted hair and patchy hair loss, typically starting on animals’ backs or around their feet.
Sores along the back or lower legs.
Raw, pink or bleeding skin in severe cases.

A lack of veterinary attention could lead to secondary infections that extend into the bloodstream or organs. Consult your veterinarian to speed up healing, ease discomfort and even prevent death.

Summer sores: Fly-transmitted wounds that won’t heal

Summer sores , or cutaneous habronemiasis, are open wounds that won’t heal. They’re caused by parasitic worms transmitted by flies — especially as fly activity increases during the summer. An immature habronema worm enters the body through the bite of a fly, specifically, by a housefly or stable fly .

Signs of summer sores include:

Red, round wounds that won’t heal.
Sores near eyes, lips or existing wounds.
Inflammation and intense itching, caused by the worm burrowing inside the skin.

“The flies are attracted to areas where there’s moisture,” Edwards says. “They bite around the eyes, lips and especially where there are wounds or damaged skin.”

To protect livestock, owners should consider fly control in barns and pastures. They should also consult their veterinarian as soon as signs are spotted because summer sores don’t heal on their own. Without proper treatment, sores may become larger and more painful, usually leading to reduced mobility and a decline in overall health.

Healthy herds with expert support

Protecting livestock skin during the summer is essential to keeping animals healthy and productive. By staying alert to early signs of skin problems and working closely with veterinarians and diagnostic labs like TVMDL, livestock owners can prevent minor irritations from turning into serious, costly issues. With proper care and management, animals can stay comfortable and healthy during the summer.

Your Next Read: 10 Toxic Pasture Weeds to Watch For

Kansas Beef Producers Beware: A Case of Theileria Found

Thu, 17 Jul 2025 18:51:08 GMT

Theileria orientalis ikeda, a protozoan parasite that infects red and white blood cells and can lead to anemia and, in some cases, death, has been found in Kansas.

The primary insect vector is the Asian longhorned tick (ALT) . According to the Kansas Veterinary Diagnostic Laboratory (KSVDL) ALT has not been found in Kansas but has been found in Missouri, Arkansas and in Oklahoma most recently in the county adjacent to Labette County, Kan.

The disease can be spread through multiuse needles and insect vectors.

KSVDL reports the infected calves in the case were purchased on the East coast and imported into Kansas for feeding.

If you are witnessing any of these clinical signs in cattle of all ages — anorexia, lethargy, dyspnea, icterus or death — please consider this new pathogen.

KSVDL also stresses producers need to be wary of importing cattle without testing for this disease. KSVDL has a polymerase chain reaction (PCR) (MDL7130) that identifies both Anaplasma and Theileria. As with all PCR’s, whole blood (purple top tube) is the appropriate antemortem sample. Fresh spleen is the appropriate postmortem sample.

KSDVL has a map of where the disease has been confirmed by KSDVL testing.
For more details on the disease, you can view a webinar produced by KSDVL.

Success From The Start: Calf Health Starts Before Birth

Tue, 15 Jul 2025 13:11:35 GMT

If a calf struggles during its first 60 days of life, it’s going to carry that through all phases of production. Starting a calf, whether in a traditional beef or beef-on-dairy scenario, the right way is paramount to the lifetime health of that animal.

This is the message stressed by Dr. Taylor Engle, Four Star Veterinary Services, during episode eight of “ The Future of Beef Show ” podcast. He says success starts before a calf is born.

“There are a lot of really good genetics in the beef industry we can use. However, if you put that calf in an environment to fail, genetics does not play a factor,” he says. “We have to do everything right from an environmental piece to maximize the genetic potential.”

Check out the podcast to learn more about these five key messages discussed by Engle and the podcast’s hosts:

Environment matters more than genetics. Engle emphasizes if you put a calf in an environment to fail, genetics won’t save it. Management and early life conditions are critical to an animal’s success.
Calf health starts before birth. Proper care of the cow before calving, quality colostrum and a clean birthing environment are crucial for a calf’s lifetime health.

Engle encourages producers to think about the cow’s condition before, during and after breeding.

“Everyone gets really fired up — and rightfully so — about colostrum. Not all colostrum is created equal,” he says. “It’s what we are doing to set that cow up to have the best colostrum for that calf. Whether it’s beef-on-dairy or native, the right vaccines for the right diseases at the right time matters.”
Communication is key across the production chain. Sharing information about calf health, vaccination history and management practices between different stages of production can significantly improve overall animal performance.

Engle encourages producers to record vaccination and treatment information and then share it. Communicating with the feedyard is important to help the feeder decide on how to treat cattle.
Don’t be quick to treat — understand the root cause. Instead of immediately administering antibiotics, veterinarians should first investigate the underlying management or environmental issues causing health problems.

“We were trained to think it’s a disease, and more often times than not, there is a disease present. But there’s been something along the process where we have stressed that animal and caused disease,” he explains. “We’re always looking at it from an environmental standpoint and a management standpoint — the calf isn’t the culprit. What’s going on? Why did that calf break with respiratory disease? They don’t spontaneously get sick. Something happened. Was it a weather, feed or stressful event?”

He adds management strategies and mentality can be keys to determining the cause of a sickness.

“It’s a hard thing — whether you’re a nutritionist or vet — to have that hard conversation with a producer, be upfront with them and say, ‘It’s something we’ve done,’” he says. “A lot of times, there’s management practices that messed up along the way, and the result is a disease.”

In his practice, he works with the producer to help them understand and recognize the management strategies to improve the outcomes.

“In the beef industry, a lot of the mentality is, ‘We’ve never done it this way,’” he says.
“In comparison, in the poultry and pig industries, producers will say, ‘If it increases my production, I’ll do it.’ They have the mentality of being willing to give something a try to see if it increases health.”

Engle adds, “I always tell producers if you want A results, you got to give A effort,” he explains. “You can’t have a C -plus effort and expect A results.”
Stress management is more important than treatment protocols. Focus on reducing stress and creating optimal conditions for calves, rather than relying solely on medical interventions.

“The calves don’t lie,” Engle says.

He emphasizes the importance of careful observation, advising producers to “read calves every day” and make real-time adjustments.

Beef-on-Dairy Calf Health
Engle also has extensive experience with beef-on-dairy calf management and production and discussed how those animals compare to traditional beef calves, highlighting how multiple touch points and movements bring beef-on-dairy calves unique challenges — including different feeding systems and varied vaccine and management protocols at each location.

As a positive, he says, “In the beef-on-dairy space, we have all the data points, or we have the opportunity to collect all the data points. Then you can start making decisions.”

With this complex — but data-rich — production model, there is significant potential for improving calf health and performance.

Engle challenges producers to think holistically about animal health, management and production.

“It’s not the animal that’s usually causing the problems,” he says in summary. “It’s usually producer’s management or oversight. As farms have gotten bigger, the skill gap as we go higher actually closes. Everybody who has 10,000-head of cattle on feed, or more, probably knows a lot about feeding cattle. But what are you going to do for a competitive advantage that the next feedyard isn’t? I think a lot of that’s looking internally at your management strategies and your consulting team. It’s a team effort to get to where you want to be. Set those goals and look at what you need to do better to be where you want to be in the next five to 10 years.”

Protect the Herd: The Signs to Watch for Calf Pneumonia

Wed, 09 Jul 2025 11:44:05 GMT

Pneumonia in young calves is an important contributor to death loss before weaning. Many veterinarians and cattle producers think of post-weaning respiratory disease, also known as Bovine Respiratory Disease (BRD), when they think about pneumonia in cattle; but calves can get pneumonia while they are still suckling their dams.

Bob Larson, K-State veterinarian, says because the risk factors associated with pre-weaning respiratory disease differ from BRD in stocker and feedlot cattle, which is usually associated with commingling and transportation.

“Our understanding of how to prevent and control BRD in post-weaned calves is not sufficient to address pneumonia in suckling calves,” he says. “Several studies investigating calf pneumonia have reported that an average of 3% to 11% of calves are expected to suffer from the disease each year. In addition, nearly 1.5% of calves will die from pneumonia before they reach the age of weaning; which makes it the second leading cause of pre-weaning death with only scours causing more losses.”

The most likely age for calves to be diagnosed with pneumonia is between 70 and 150 days of age.

Larson says cases of pneumonia are most likely to appear in:

Herds that have more cases of calf scours.
Herds that bring in nursing calves from outside herds to graft onto cows that lost their calves.
Creep-fed calves.
Herds that synchronize cows.

“Calves born after a difficult birth and calves that failed to consume enough colostrum have been shown to be at higher risk of getting sick and dying before reaching weaning age,” Larson explains.

Veterinarians indicated in a survey that weather, calving in confinement, failing to adequately vaccinate the herd, and nutritional deficiencies were also suspected for contributing to the risk of calf pneumonia.

Signs of Pneumonia

“Many times, the first sign that a herd has a problem is when a calf is found dead,” Larson warns. “Because death in young calves can also be caused by other diseases such as blackleg, digestive tract disease, or trauma, a veterinarian will probably need to examine the dead calf and may need to submit samples to a diagnostic laboratory to identify the cause of death.”

If you find calves that show signs of pneumonia such as rapid breathing, laying down and being reluctant to rise, and having a high temperature should be treated with an appropriate antibiotic after consulting with your veterinarian.

Tips for Prevention

Larson says vaccinating calves against viruses such as bovine viral diarrhea (BVD), infectious bovine rhinotracheitis (IBR), bovine respiratory syncytial virus (BRSV), and bacteria such as Mannheimia haemolytica and Pasteurella multocida may help prevent outbreaks of calf pneumonia or reduce the severity of disease, but we know that a young calf’s immune system is not able to respond as well to vaccinations as an older calf’s.

“Because even a calf with a good immune response can be overwhelmed by a large exposure to germs, a successful plan to prevent disease in young calves needs to involve more than just vaccinations,” Larson adds.

He says the herds that have the best calf health have a short calving season and few heifers and cows experiencing calving difficulty. In addition, try to keep young calves away from mud and other calves as much as possible.

“Cows that calve in good body condition and that are on a good plane of nutrition are more likely to have healthy calves,” Larson says. “The best disease-control strategy is to focus on having good overall health of the cows and calves by meeting the herd’s nutritional needs, providing a good environment and timely use of vaccinations in the cows and calves.”

In summary Larson says, if calves are affected with pneumonia while suckling their dams on summer range, you should be prepared to recognize and treat cases as early as possible with appropriate antibiotics in order to minimize death losses.

Your Next Read — Combating Pinkeye: Tips for Detection and Treatment

Veterinary Pharmaceutical Solutions Unveils Innovative Pharmacy Expansion

Thu, 19 Jun 2025 13:37:09 GMT

Veterinary Pharmaceutical Solutions (VPS), a livestock pharmacy compounding, announces two extraordinary milestones in the company’s history: The completion of a pharmacy expansion in St. Peter, Minn., and the company’s 30th anniversary.

The pharmacy expansion nearly doubles the size of the existing facility and is designed to be the highest quality compounding pharmacy in the industry. It features multiple state-of-the-art compounding suites to advance current solutions and develop new products, space to expand R&D, a microbiology lab and warehouse space.

All of these features enable VPS to elevate its operations and more quickly create innovative solutions for veterinarian and producer customers.

“As we celebrate 30 years of innovation, this expansion is really about listening to the needs of our customers and providing solutions,” said Dean Warras, CEO of the company.

“Every part of the addition—from the new compounding suites to the R&D and microbiology labs—is designed to help us deliver even greater quality, innovation and solutions to meet the evolving needs of the livestock and poultry industries,” Warras adds.

With this expansion, VPS continues to grow its capability in animal drug compounding, a critical service that allows for the customization of medications to address distinct animal health requirements. The expansions, with FDA oversight, adhere to further national standards and align with state Boards of Pharmacy in their respective areas of operation.

“This expansion gives us space to install new equipment and allows for the complete segregation of customized medicines where needed,” said Stacy Peters, chief commercial officer.

“We can research non-traditional approaches to developing new and effective compounded solutions for challenges our veterinarians and producer customers are seeing on-farm.”

VPS broke ground on the pharmacy expansion on August 1, 2024, and received occupancy approval from the Minnesota Board of Pharmacy for the new space on April 1, 2025.

Beef Producers Be Aware: Dangerous Asian Longhorned Tick Continues Migrating West

Wed, 18 Jun 2025 13:24:33 GMT

The Asian Longhorned Tick (ALHT) poses a serious threat to cattle health. ALHTs carry Theileria, which is a protozoan parasite that infects red and white blood cells. It can lead to anemia and, in some cases, death.

ALHTs are native to eastern Asia, eastern China, Japan, the Russian Far East and Korea but were introduced to Australia, New Zealand and western Pacific Islands. In other countries, it can also be called a bush tick, cattle tick or scrub tick.

In the U.S., ALHT was first detected in New Jersey in 2017. Since then, it has spread to more than 20 states with recent confirmations in Illinois , Michigan and Iowa .

According to USDA’s Animal and Plant Health Inspection Service (APHIS) ALHTs are known to carry pathogens, which can cause disease and may also cause distress to the host from their feeding in large numbers. For example, a dairy cow may have a 25% decrease in milk production after becoming a host.

A female can reproduce without a mate and lay up to 2,000 eggs at a time. This can cause great stress on a heavily infested animal and result in reduced growth and production. A severe infestation can kill the animal from excessive blood loss.

Asian longhorned tick life stages and relative actual size.

(Photos of unfed ticks by Centers for Disease Control. Photos of engorged ticks by Jim Occi, Rutgers, Center for Vector Biology.)

What does it look like?

Unfed ALHTs range from a light reddish-tan to a dark red with brown, dark markings. While the adult female grows to the size of a pea when full of blood, other stages of the tick are very small — about the size of a sesame seed.

Adult females are a grey-green with yellowish markings. Male ticks are rare.

APHIS reports it only takes a single tick to create a population in a new location.

The above photos are of a AHLT engorged (on the left) and an adult AHLT not engorged.

(New Jersey Department of Agriculture)

ALHTs need warm-blooded hosts to feed and survive. They have been found on various species of domestic animals — such as sheep, goats, dogs, cats, horses, cattle and chickens — and wildlife. The tick has also been found on people.

What are the health risks?

APHIS says ALHTs are not known to carry Lyme disease, but they can cause tickborne diseases affecting humans and animals such as:

Rocky Mountain spotted fever
Heartland virus
Powassan virus

APHIS says those diseases have not been confirmed outside of a laboratory setting in the U.S. In addition, U.S. ALHT populations can transmit U.S. Theileria orientalis Ikeda strain (Cattle theileriosis) in the laboratory.

In an Iowa State University release , Grant Dewell, Extension beef veterinarian and associate professor, says cattle affected by Theileriosis will show signs of lethargy, anemia and difficulty breathing. They may develop ventral edema, exercise intolerance, jaundice and abortions.

“Although signs of Theileriosis are similar to anaplasmosis, younger animals and calves often display more severe signs compared to mature cows and bulls,” he says. “Due to anemia from both tick infestation and Theileria, the risk of death can be elevated. If cattle producers suspect either Theileria or ALHT, have a veterinarian collect appropriate samples and submit them to a veterinary diagnostic lab.”

According to an Oklahoma State University press release , under laboratory conditions ALHT is a competent vector of numerous pathogens that can cause disease in humans, including Rickettsia rickettsii (Rocky Mountain Spotted Fever), Heartland Virus and Powassan Virus.

In “ Clinical Infectious Diseases, ” Bobbi Pritt, MD, MSC, with the division of clinical microbiology at the Mayo Clinic in Rochester, Minn., reported a human bite that occurred in New York in 2019. She says though the report of a human bite isn’t surprising, it proves the invasive longhorned tick continues to bite hosts in its newest location.

“This is extremely worrisome for several reasons,” she writes. “One reason is Asian longhorned ticks can carry several important human pathogens, including the potentially fatal severe fever with thrombocytopenia syndrome (SFTS) virus and Rickettsia japonica, which cases Japanese spotted fever. While these pathogens have yet to be found in the United States, there is a risk of their future introduction.”

Also, Pritt says several other human pathogens have been detected in the ticks, but it’s not clear if the ALHT species are able to transmit them to humans. They include Anaplasma, Ehrlichia, Rickettsia, and Borrelia species. Lyme disease is caused by Borrelia burgdorferi bacteria.

She warns the organisms are present in states where ALHTs have been found and that it’s possible the tick — known to be an aggressive biter— might be able to transmit Heartland virus given its close relationship to SFTS virus.

How to Tackle Ticks

According to APHIS, various strategies effectively mitigate tick populations on hosts and in the environment.

Regular tick treatments should be effective against ALHTs. Consult your veterinarian or agriculture extension agent about which products to use.
Check your livestock for ticks regularly.
Safely remove ticks from people and pets as quickly as possible. If you think you’ve found an ALHT, seal it in a zip-top bag and give it to your veterinarian for identification.
Habitat modifications can help prevent ticks on feedlots and pastures. This may include mowing grass, removing trees, reducing shade by thinning trees, understory removal and placing mulch barriers.
Apply acaricide using label instructions to tick habitats, such as woodland edges and grassy patches, during times when ticks are most actively seeking hosts. Although it varies by year, ALHTs are generally active from March to November. Consult your state and local regulations for approved acaricides.

“Cattle producers should aggressively control external parasites this summer,” Dewell summarizes. “Insecticide ear tags alone are not enough to control ticks. Consider incorporating a back rubber or regularly applying a pour-on during the summer. Pyrethroid-based products are also available that include a tick control label. If an increase in tick infestations is observed, an avermectin pour-on may be the best intervention.”

Your Next Read: 1,500-lb. Carcasses the New Normal, Not the Exception

Two Key Tips to Stop Persistently Infected Calves Before They Start

Tue, 17 Jun 2025 15:52:51 GMT

At first glance, a persistently infected (PI) calf may look just like any other in the herd. But beneath the surface, these calves are silent spreaders, continuously shedding bovine viral diarrhea virus (BVDV) and exposing healthy herd mates to infection.

How PI calves risk herd health
PI calves are animals that become infected with BVDV during their time in utero. When the calf is infected before their immune system is able to recognize the virus as foreign, they can become a PI calf. This enables the virus to live and grow within that calf indefinitely.

“There are many consequences that can stem from a BVDV PI calf,” said Jen Roberts, DVM, Boehringer Ingelheim. “The virus itself does a very good job of suppressing the immune system, and because of that, you may see an increase in the incidence of other diseases, like respiratory disease in calves or mastitis in a milking herd. There can also be significant reproductive repercussions like early embryonic losses, abortion and birth defects. While these concurrent diseases are not necessarily caused by BVDV, the immunosuppressive effects of the virus make animals more susceptible to other illnesses.”

PI cattle can shed BVDV through many avenues, including respiratory secretions that spread the virus through the air of confined spaces, and bodily fluids such as milk, saliva, mucus, urine and manure.

Biosecurity can stop PI cattle from entering the herd
While maintaining a closed herd is the best way to prevent BVDV from establishing itself on your operation, it’s not always realistic. Dairy consolidations, expansions, off-site heifer growing, and even taking animals to shows are all common events for many farms.

“Any time you have cattle leaving the farm and coming back, there’s a chance for them to be exposed to a PI animal and become acutely infected with BVDV,” explained Dr. Roberts. “Even those acutely infected animals can shed the virus for a couple of weeks, and if they come in contact with cows that are at the right point in gestation for the fetus to become infected, it can cause a PI calf to be born.”

Dr. Roberts shares that testing for PI animals, and quarantining any new or returning animals, are great ways to prevent BVDV from finding a long-term home within your herd.

“The acute infection period is very short, usually 10 to 14 days, so if it is possible to quarantine new herd additions, the recommended period of isolation is two weeks prior to commingling with the rest of the herd,” continued Dr. Roberts. “If you’re sending animals to a heifer grower, especially one raising heifers for multiple operations, I always recommend that the calves go to a heifer grower that requires PI testing.”

Prevent PI calves through vaccination
“The most common way BVDV spreads is through PI calves, so it’s also important to develop a targeted vaccination program that prevents BVDV PI calves from being born into your herd,” stressed Dr. Roberts.

Vaccinating cows with a modified-live virus vaccine labeled for BVDV like EXPRESS FPhelps protect their health and reproductive efficiency, and enables them to deliver healthy, PI-free calves. That same pre-breeding vaccine will also help cows produce antibody-rich colostrum to protect calves from BVDV and other respiratory disease threats right after birth.

When a calf is infected with BVDV in utero, it will be born persistently infected and will shed the virus for their lifetime.

(Boehringer Ingelheim)

When building a herd with strong immunity, vaccination shouldn’t stop with the dam. While maternal antibodies offer initial defense against disease, that protection wanes over time, opening the door for a gap in calf immunity. Research has shown that when exposed to a PI calf, 70% to 100% of non-vaccinated or immune-suppressed cattle become infected.¹Fortunately, calves as young as 30 days of age can still generate a strong immune response in the face of maternal antibodies.

In a study, 30-day-old calves, with maternal antibodies present, were vaccinated with a uniquely adjuvanted five-way plus Mannheimia haemolytica modified-live virus (MLV) injectable-vaccine protocol, or an intranasal- and injectable-vaccine protocol. Five months later, both groups were challenged with BVDV Type 1b and M. haemolytica.

Results show that the five-way plus M. haemolytica MLV vaccine protocol provided a stronger immune response against BVDV Type 1b. It also decreased the level of BVDV shedding and kept rectal temperatures lower for several days, compared to the intranasal- and injectable-vaccine protocol.²

Not all respiratory vaccines are the same. Dr. Roberts suggests working with your herd veterinarian to solidify a vaccine protocol that best fits your operation’s needs.

BVDV Type 1b is the leading cause of PI calves
Thirty years ago, the majority of BVDV cases were caused by Type 1a. In more recent years, Type 1b has emerged as the most prevalent subspecies of BVDV in the United States, accounting for roughly 70% of reported cases.³

Viruses often mutate to escape detection by an animal’s immune system. Over time, viral mutations resulting from environmental pressures can lead to changes in the prevalence of viral strains, causing clinical disease.

“The most surprising thing to me about BVDV has been the divergence of the different subspecies over the past 20 to 30 years,” said Dr. Roberts. “We know there are differences in the breadth of BVD protection offered in the commercially available vaccines, and it’s important to reevaluate vaccination protocols periodically as patterns in clinical diseases shift.”

Due to the increasing risk of BVDV Type 1b, Dr. Roberts recommends working with a veterinarian to establish a sound vaccination protocol that includes adequate protection against this particular subspecies.

“It’s important to get at least two — if not three — doses of a modified-live virus vaccine that’s labeled to protect against BVDV 1b administered by the time that calf reaches breeding age,” she pointed out. “We want to make sure that each heifer on the farm has optimal protection prior to breeding, in order to reduce the likelihood that she gives birth to a PI calf.”

While BVDV presents serious challenges, producers have reliable tools like vaccination, testing and biosecurity to manage it. Staying proactive and aware of BVDV impact is the first step in keeping your dairy herd healthy and productive for the long run.

References:

¹Fulton RW, Briggs RE, Ridpath JF, et al. Transmission of bovine viral diarrhea virus 1b to susceptible and vaccinated calves by exposure to persistently infected calves. Can J Vet Res 2005;69(3):161–169.

²Perkins-Oines S, Dias N, Krafsur G, et al. The effect of neonatal vaccination for bovine respiratory disease in the face of a dual challenge with bovine viral diarrhea virus and Mannheimia haemolytica. Vaccine 2023;41(19):3080–3091.

³ Fulton RW, Cook BJ, Payton ME, et al. Immune response to bovine viral diarrhea virus (BVDV) vaccines detecting antibodies to BVDV subtypes 1a, 1b, 2a, and 2c. Vaccine 2020;38(4)4032–4037.

Fine-Tuning First-Lactation Performance with Smarter Data Management

Tue, 17 Jun 2025 15:31:38 GMT

It’s not easy to be the new kid in school. Or a first-lactation animal in a herd of older cows.

“Not only are first-lactation cows facing a new environment, a new ration and numerous physical changes that accompany giving birth, but they also have to adapt to a new social structure and daily routine, all of which is out of their control,” says Steve Pavelski, Nedap large herd specialist. “All of this adds up to stress and behavioral hurdles for these animals.”

To ease this transition, many producers are grouping first-lactation cows separately and using automated monitoring tools to better support them in the weeks after calving. These strategies are proving critical to long-term productivity.

First-lactation learning curve

How different are fresh heifers from mature cows? Research says: Quite a bit.

For example, first-lactation cows have different habits from older cows:^[1]

They are often more timid at the feed bunk due to their lower social status, especially during the week of calving, and eat less than other cows throughout the transition period.
Researchers also found that younger animals eat more slowly and more frequently than cows in their second lactation or higher.
Plus, first-lactation cows have different resting habits. They have shorter lying bouts, change their lying position more frequently and walk more than older animals.
When grouped with other first-lactation cows, they spend more time eating and lying down than when mixed with mature cows.

“This is a whole new scene for these animals,” says Pavelski. “We work with many herds that keep fresh heifers in smaller groups for the first two weeks to 30 days after calving. Sending a fresh heifer, especially one fewer than 10 days in milk, into a crowded pen often sets her up to struggle.”

Data-driven results

Research shows poor transition from pregnancy to lactation often results in the loss of 10-20 pounds of peak milk yield, which could equal 2,000-4,000 pounds of untapped milk yield.^[2]

However, dairies with access to accurate monitoring data have discovered that not only do they have a better handle on how all cows fare during transition, but also that moving healthy older cows out of transition groups faster results in improved performance of first-lactation cows, too.

“The Alta Cow Watch system is very effective for our day-to-day work and has made checking fresh cows more efficient,” says Ryan Nelson, Ohlde Family Farms, Linn, Kansas. “We’re able to catch something sooner so we can get her back to 100% and back to a good lactation.”

Better grouping, better gains

Monitoring system data fed into herd management software enables users to establish movement criteria. As trends emerge, reports indicate how well animals are adjusting to lactation demands and offer insight as to when cows should leave the fresh pen for lactation groups.

This strategy keeps cows that need more attention, such as first-lactation animals, in smaller groups while returning those meeting performance criteria to lactation groups and a higher plane of nutrition after a shorter fresh pen stay.

“The mature cows can move to the lactation group quickly, giving first-lactation heifers the space and time to adapt at their own pace,” Pavelski explains. “Monitoring data gives us a clear picture of how they’re adjusting and when interventions are needed.”

With actionable data in hand, dairies can make quicker, more accurate decisions. Instead of holding all cows in transition pens longer than necessary, producers can move animals based on performance, not guesswork or predetermined timeframes.

“The goal is to manage each cow as an individual, while letting the rest of the herd just be cows,” Pavelski concludes.

Visit nedap-livestockmanagement.com to learn more.

About Nedap

Nedap creates Technology for Life: technological solutions that help people become more successful and happier in their professional lives. Nedap’s Digital Twin Technology bridges the physical and digital worlds, offering real-time insights and automation in Livestock, Healthcare, Retail, and Security. Nedap Livestock helps farmers to optimize the performance and well-being of individual cows while minimizing workload and resources. This way, Nedap improves life on the farm for both people and animals, helping to reduce the environmental footprint of dairies worldwide. Nedap N.V. has a workforce of over 1,000 employees and operates on a global scale. The company was founded in 1929 and has been listed on Euronext Amsterdam since 1947. Its headquarters are located in Groenlo, The Netherlands.

Unlocking Success with Cow Herd Health Metrics: A Scorecard Approach

Tue, 27 May 2025 17:44:23 GMT

Tracking performance and evaluating herd success is a year-round process. Similar to tracking athletes, consider developing a scorecard to monitor your herd. Understanding how your herd is performing throughout the year is important when considering management, nutrition and culling decisions.

The first scorecard suggested was post-calving ; the next one to consider is herd health metrics. Illness and death loss in a cow herd are situations cattle producers must routinely address.

To help producers know where their herd health metrics should be, experts at Kansas State University’s Beef Cattle Institute offered some guidelines during a recent “Cattle Chat” podcast .

“The first metric in cow-calf operations that I look at is the first treatment response percentage,” says Brian Lubbers, K-State veterinarian.

He recommended producers aim for an 85% to 90% treatment success rate when treating one of the most common illnesses: Bovine Respiratory Disease, also referred to as BRD. He says that metric can be deceiving.

“Producers who aggressively treat BRD cases are likely treating some animals that didn’t have BRD, and that leads to a high spontaneous recovery rate,” Lubbers says. “If you are seeing a 100% first treatment success rate, you may be treating some animals who didn’t need the treatment. Very high treatment response rates should at least trigger a conversation with your veterinarian about case definitions.”

K-State veterinarian Bob Larson says another metric that producers should be aware of is the percentage of death loss in the calves. During the first year of life, there are three key times when calves are more susceptible to death: at birth, between birth and three weeks of age, and from about one month to weaning, he says.

For each of these periods, producers can expect a 1% to 2% loss, Larson explains, however, that percentage will vary from year to year.

“In the first year of life, difficult births, scours and pneumonia are some of the reasons that calves get seriously ill and sometimes die,” Larson says.

K-State beef nutritionist Phillip Lancaster says what he monitors in the herd is the body condition of the cows.

“If the cows are receiving good nutrition and maintaining their body condition, that is an indicator of the overall health of the herd,” Lancaster says.

Along with those metrics, Logan Thompson, K-State beef cattle extension sustainable grazing specialist, recommends producers treat the herd against parasites as part of an overall wellness program.

“Treating the herd against parasites is an easy win from a production efficiency and cattle longevity standpoint, and it increases the rate of passage of grass through the rumen,” Thompson says. “It is a hard metric to measure, but in some herds, cattle that are treated for parasites have an increased efficiency between 20[%] to 30%.”

In summary, the key takeaways from the podcast are:

Health metrics are multifaceted and require careful tracking.
Different perspectives (veterinary, nutritional, sustainability) offer comprehensive insights.
Metrics should be specific, measurable and contextualized.
Collaboration with veterinarians is crucial for effective health management.

Your Next Read: Early Shedding Cows Produce Heavier Calves at Weaning

National Mastitis Council Plans Regional Meeting, Registration Now Open

Thu, 15 May 2025 14:19:10 GMT

The Global Milk Quality Organization invites you to attend the 2025 National Mastitis Council (NMC) Regional Meeting, set for July 22-24, in Rochester, N.Y., at the Hyatt Regency Rochester.

With a theme of “Clearing Hurdles to Improve Milk Quality,” this event will bring together dairy producers, veterinarians, researchers and industry professionals for a collaborative exchange of knowledge and innovative practices to tackle key challenges in milk quality and udder health.

Find details about the NMC Regional Meeting at: https://www.nmconline.org/2025-regional-meeting-agenda . To register for this event, go to: https://bit.ly/NMC2025Regional .

As the dairy industry continues to evolve, so do the obstacles that hinder optimal milk quality and production, and animal welfare. The NMC Regional Meeting will feature expert-led sessions on emerging mastitis pathogens, on-farm milk quality strategies, antimicrobial stewardship and technologies for monitoring herd health.

“Our goal is to help dairy professionals identify and overcome the barriers that hinder milk quality,” said Rick Watters, an NMC board member and regional meeting co-chair. “By bringing together some of the brightest minds and most practical tools in the field, we aim to drive significant progress for enhancing udder health.”

The 2025 NMC Regional Meeting includes short courses, general sessions, panel discussions, dairy farm tours and networking opportunities designed to foster practical learning and actionable solutions.

Short Course topics and presenters* to include:
Troubleshooting Bacteria Counts in Conventional Milking Systems: Paul Virkler, Quality Milk Production Services, and Rick Watters, AgroChem

Milking System Design & Analysis: Roger Thomson, MQ-IQ Consulting and Michigan State University

Mastitis Microbes I: Let’s Figure Out the Bugs Behind the Battle: Quinn Kolar and Michael Zurakowski, Cornell University

The Milking Routine: Lisa Ford, Cayuga Marketing, Kaitlyn Lutz, Cornell University, and Francisco Mendoza Gomez, Newmont Farms (taught in Spanish)

Troubleshooting Bacteria Counts in Automated Milking Systems: Kira Andersen, Lely, and Guy Séguin, Dairy Farmers of Ontario

Milking System Vacuum and Airflow Testing: Roger Thomson, MQ-IQ Consulting and Michigan State University (hands-on training using the “Teaching Parlor”)

Judicious Use of Antimicrobials: Matt Chuff and Tracy Potter, Perry Veterinary Clinic

The ABCs of Milking Machines: Operation, Cleaning and Inspection: Carolina Pinzon, University of Wisconsin, and Dario Roma, DCR Consulting (taught in Spanish)

Identification of Mastitis-causing Organisms Using On-farm Methods: Quinn Kolar and Michael Zurakowski, Cornell University

Wash System Analysis: Roger Thomson, MQ-IQ Consulting and Michigan State University, and Rick Watters, AgroChem

General Session topics and presenters* to include:
Bedding Management: How to Interpret Bedding Bacterial Counts – Felipe Peña Mosca, Cornell University

Beyond Cell Count: Non-traditional Measures of Milk Quality – Nicole Martin, Cornell University

Milk Quality Standards: Beyond SCC and SPC – Kaitlyn Briggs, fairlife

Capitalizing on Sensor Technology – Julio Giordano, Cornell University

Using Artificial Intelligence to Interpret Data Silos – Elsa Vasseur, McGill University

How to Use Camera Technology Without Infringing on Employees’ Privacy Rights

Panel Discussion: How Dairy Farms are Using Artificial Intelligence and Camera Technology

*Topics and presenters subject to change.

Plus, tour some of New York’s finest dairy farms on July 24. The tour features Reyncrest Farms, Corfu, N.Y.; Bonna Terra Farms, Bloomfield, N.Y.; and Rudgers Registered Jerseys, Attica, N.Y.

Additionally, you won’t want to miss NMC’s Taste of New York – set for the evening of July 22. Taste some of the Empire State’s finest cheeses, wines and beers. And, participate in NMC’s first-ever chocolate milk tasting contest.

To make your hotel reservation at the Hyatt Regency Rochester, go to: https://bit.ly/NMCregionalmeetingHotel . Book your hotel room by June 30 in the NMC room block to take advantage of the discounted rate of $129 per night (not including taxes and fees).

Your next read: Can Oxytocin Boost Colostrum?

AABP Annual Conference will 'Focus on Value'

Wed, 07 May 2025 14:32:28 GMT

The 58^th American Association of Bovine Practitioners (AABP) Annual Conference will be held Sept. 11-13 in Omaha, Neb., at the Chi Health Center Convention Center. Registration is open at https://aabp.org/meeting/ . Early registration ends July 31.

“The theme for this conference is ‘Focus on Value’,” says AABP President-Elect and 2025 Program Chair Dr. Callie Willingham.

“Thinking about being in Omaha, our program committee naturally thought of Warren Buffet, the ‘Oracle of Omaha’, and one of his quotes being along the lines of ‘cost is what you pay for something, but value is what you get’. That quote really hit home with us,” Dr. Willingham says.

“As veterinarians and business owners, we often focus on the costs charged to our clients and don’t always take the time to focus on the value that those services provide to our clients and their animals. Veterinary practices also provide immense value to their team members and their communities,” she adds.

Willingham says AABP is very excited to welcome keynote speaker Natasha Nicholes, founder of We Sow We Grow, and an urban farmer on the South Side Chicago. “She’ll touch on the importance of agriculture and food production, in all forms, in supporting and uniting communities.”

“The core mission of AABP has always been to provide continuing education to our members which includes cattle veterinarians, credentialed veterinary technicians and students,” adds AABP Executive Director Dr. Fred Gingrich. “Omaha has historically been a great location for our annual conference and we look forward to inviting our members back to learn, network and socialize.”

The conference’s preconference seminar schedule offers something for everyone. “I am among the many bovine veterinarians who have said ‘an AABP preconference seminar that I took earlier in my career changed my life’,” says AABP Vice President and Preconference Seminar Chair Dr. Mark Hilton. “What I learned I immediately put to practice and allowed me to offer a service I would have never been able to offer if not for that seminar.” See preconference seminar information at https://aabp.org/meeting/preconference.asp .

Scientific sessions at the conference will include cutting-edge information on beef and dairy medicine and health, practice management, clinical skills, preconference seminars, clinical forums, research summaries, practice tips, student sessions, mental health sessions and more (see the schedule at https://aabp.org/meeting/conference.asp ). The American Association of Small Ruminant Practitioners will meet jointly with AABP. The conference will be submitted for RACE-approved continuing education.

Other events include the student Quiz Bowl, student case presentations, research summaries, awards and scholarships, the Job Fair, the 12^th 5K Stampede Fun Run, the Amstutz live and silent scholarship auctions and more. Members and affiliated partners can donate and/or browse auction items at https://aabp.org/auction/ .

This will be the 12^th year for the 5K Stampede Fun Run sponsored by Boehringer Ingelheim, with proceeds benefitting the Amstutz Scholarship Fund. Conference attendees can sign up for the 5K when they register for the conference.

Family-friendly, the conference also offers a childcare/family room and complimentary registration for childcare givers.

Find all conference information at https://aabp.org under the Continuing Education tab.

#AABP2025

AABP is a membership-based, not-for-profit organization serving cattle veterinary medicine professionals across the United States, Canada and other countries. Visit https://aabp.org and like us on Facebook.

Streamline Spring Cattle Processing with These 3 Stress-Reducing Steps

Thu, 01 May 2025 15:46:11 GMT

Reducing stress during livestock handling can increase productivity, maintain or improve meat quality, reduce sickness and enhance animal welfare. Implementing low-stress handling techniques when working with cattle is important to reducing stress.

As producers prepare for spring processing, Beth McIlquham, University of Wisconsin-Madison regional livestock educator, encourages producers to consider these low-stress handling strategies.

“While temperament in cattle is moderately heritable, environment does play a role and even cattle that are less docile will benefit from low-stress handling methods,” Mcllquham says. “A good handler can help reduce fear in an animal, which is the primary driver of negative consequences associated with handling stress.”

Even if the animal is not experiencing any pain, fear can still cause physical responses in the body, such as high cortisol levels. These responses can ultimately lead to increased susceptibility to illness, lower meat quality and overall lower performance.

Mcllquham says one negative handling experiences can affect future handling situations.

Identifying stress through body language
Cattle in a state of fear or under stress can be identified through their body language. Obvious signs of fear in cattle are running, kicking, vocalizing and aggressive behaviors toward handlers. Subtle signs of fear are heavy breathing and showing the whites of their eyes. Stressed cattle can cause serious injury to themselves and humans. Relaxed cattle are quiet and walk or trot calmly. When low-stress handling techniques are used, the risk of injury is lowered.

“Besides increasing performance and lowering sickness and injury rates, consumers have indicated that they care that their food is humanely raised,” McIlquham explains. “Implementing low-stress handling is a great place to start and comes with many other benefits. Although it may sound like a daunting task, utilizing low-stress handling techniques can be done in smaller steps.”

Step 1: Put away the electric prod
“Our first step is to put away the electric prod,” she says. “To decrease use, place electric prods away from where you’re handling cattle but still be accessible in an emergency. This way, instead of instinctively reaching for it, the inconvenience of going to grab it can decrease electric prod use.”

Step 2: Understand cattle’s natural instincts
“We should utilize these instincts to work for us instead of against us,” she says. “The fact that cattle are prey animals drives a lot of their behaviors.”

Cattle are herd animals and like to be in groups. When moving them, keeping cattle in small groups (two to five head) can help keep them calmer and easier to handle. Additionally, cattle want to see you. Humans are naturally predators, and because cattle are prey animals, their instinct is to be able to keep handlers in sight.

Cattle want to go toward lighted areas and will resist going into darker areas. It is easier to see any potential threats in areas that are light. Keep in mind shadows can reduce cattle flow through an area.

Step 3: Study and use cattle’s natural flight zone
Good handlers study and use cattle’s flight zone and point of balance, McIlquham explains.

Two concepts are illustrated in Figure 1.

Figure 1. Flight Zone and Point of Balance

(Beef Quality Assurance Cattle Care & Handling Guides)

Walking into the flight zone makes the animal move away from the handler. Stepping out of the flight zone will take pressure off and remove the animal’s desire to continue to move away. Note that the size of flight zones varies between animals. The point of balance allows handlers to move the animal forward or backward. Stepping into the flight zone in front of the point of balance will make the animal move backward. Stepping into the flight zone behind the point of balance will drive the animal forward.

Keep in mind cattle have a blind spot directly behind them. If you approach the animal in the blind spot, they could get spooked. Walking in a zigzag pattern behind cattle helps let them know you are there.

Extra tip: Taking breaks
Calm cattle are easier to move than stressed cattle. Fearful cattle are more reactive, more easily injured, and more likely to engage in aggressive behaviors. If a handling situation does get intense, take a little break and release pressure on the cattle.

“Even taking a brief break can help both the animal and handler calm down and come back to the situation in a more positive light,” Mcllquham summarizes.

Your next read: Effective Needle and Syringe Strategies to Ensure Spring Processing Success

The Effects of Heat Stress on Dairy Cattle Development, Health and Performance

Tue, 22 Apr 2025 22:08:39 GMT

It is not breaking news that yearly temperatures on Earth have been consistently rising. Indeed, data released from NASA’s Goddard Institute for Space Studies – GISS show that the global land-ocean temperature index has consistently increased after the 1900s (see Figure 1 below).

Regardless of the many factors that have been tied to the increase in global temperature (some that were addressed in previous WSU VetMed Extension Articles ), it is evident that the agriculture is affected by such changes, including the dairy industry. With increased global temperatures, the occurrence of heat stress (a condition that occurs when the body is exposed to excessive heat, leading to an inability to regulate body temperature effectively) and its associated detrimental impacts are more likely to be observed particularly in dairy cattle.

A recent study projected the decadal increases in average heat stress frequencies by 2100, and revealed that the majority of the U.S. regions will have at least 6 to 8 additional days under heat stress/decade until 2100 ( Gunn et al., 2019 ; Figure 2).

Because of the expected differences in climate, it is important that dairy industry stakeholders work together to further 1) understand the complexity and underlying mechanisms of heat stress impacts, and 2) develop alternative strategies to mitigate the detrimental impacts of heat stress.

With that in mind, this article focuses on reviewing some of the key aspects related to heat stress impacts on cattle development, health and performance, industry economics, and mitigating strategies.

Historically, the temperature-humidity index (THI) has been the mechanism used to determine when dairy cows are heat stressed. Although there is some variation on THI cut-offs the consensus was established as a THI between 68 and 70 ( Zimbelman et al., 2009 ; Chen et al., 2024 ). Guinn et al. ( 2019 ) described the differences in mean THI between summer and winter months in the U.S. for the last 10 years (69.5 vs. 39.3, respectively), highlighting that without any heat stress abatement strategies U.S. dairy cows could be under heat stress conditions for most of the summer months.

In fact, the same study revealed differences in productive and reproductive performance between summer and winter, illustrated by reduced milk production and pregnancy rates in summer compared with winter months. Similar results were also reported by other authors, including lowered pregnancy rates in warmer months compared with colder months of the year ( Hansen, 2009 ). Both Tao et al. ( 2020 ) and Ouellet et al. ( 2020 ) depicted the detrimental impacts of heat stress on milk production and dry-matter intake (Figures 3 and 4).

Other studies have demonstrated the effects of heat stress (or contrast between warmer vs. cooler months) on the occurrence of diseases, culling, and cow welfare. For instance, cows that calved in warmer months were observed to have greater odds of retained fetal membrane (Odds Ratio = 1.6), subclinical ketosis (Odds Ratio = 2.3), displaced abomasum (Odds Ratio = 1.8), and mastitis (Odds Ratio = 1.1) as compared with cows that calved in cooler months ( Pinedo et al., 2020 ).

Al-Qaisi et al. ( 2020 ) observed a greater somatic cell count in milk from cows exposed to heat stress conditions as compared with cows exposed to thermoneutral conditions, and cows that calved in the summer were more likely develop metritis as compared to cows that calved in cooler months ( Molinari et al., 2022 ). Furthermore, Vitali et al. ( 2015 ) reported higher mortality of cattle during heat wave periods compared to subsequent periods, and an association of mortality and heat wave duration (Figure 5). Heat stress conditions have also been associated with welfare issues in dairy cattle, as cows under heat stress conditions remain in a standing position for greater periods of time (possibly contributing to lameness issues) and have greater blood cortisol levels than cows under thermoneutral conditions ( Cook et al., 2007 ; Allen et al., 2015 ; Al-Qaisi et al., 2020 ).

Considering the effects of heat stress on cattle performance, mortality, and welfare, it is not a surprise that economic losses occur. Specifically, data published in 2003 estimated that heat stress conditions cause up to $2.3 billion/year in economic losses to livestock production ($2.9 billion in 2024 considering inflation). Under heat stress abatement strategies, the economic losses drop down to $1.7 billion/year and the dairy industry represents over 50% of the costs ($897 million; St-Pierre et al., 2003 ).

A component to heat stress in dairy cattle that has received a lot of attention is the “in utero” heat stress on dairy calves. Recent studies highlighted the carryover effects of late gestational heat stress on the progeny, illustrated by lowered birth weight (-4.6 kg), lowered weaning weight (-7.1 kg), and reduced longevity ( Ouellet et al., 2020 ). Moreover, the occurrence of heat stress during the dry period is also associated with differences in offspring mammary gland structure ( Dado-Senn et al., 2019 ), adrenal gland development ( Guadagnin et al., 2024 ), behavior ( Laporta et al., 2017 ), and hormonal/metabolic biomarkers ( Guo et al., 2016 ).

Lastly, combined studies have shown the legacy effect of heat stress on offspring, as lactational performance of such offspring is also different compared to offspring generated by dams under thermoneutral conditions ( Ouellet et al., 2020 ; Figure 6).

The research findings related to the legacy effect of heat stress on offspring add another layer of importance to the topic, and suggest that the detrimental effects and economic losses previously described are potentially underestimated.

Although the complex mechanisms that underlie the detrimental effects of heat stress on lactating dairy cows are not yet fully elucidated, studies have demonstrated biological changes associated with heat stress. For instance, lipopolysaccharide-induced accumulation of IL-1β, IL-10, and MIP-1α was greater in blood collected from postpartum cows that were under prepartum heat stress conditions as compared with control cows,implying that prepartum heat stress has carry-over effects on postpartum innate immunity, which may contribute to the increased incidence of uterine disease observed in cows exposed to prepartum heat stress ( Molinari et al., 2023 ).

Other studies have depicted differences in gut, ovary, muscle, and metabolism morphology/function associated with heat stress, which could be tied to the occurrence of subsequent diseases, animal performance, reproductive performance, and mortality ( Baumgard and Rhoads Jr, 2013 ; Fernandez et al., 2015 ; Hale et al., 2017 ; Ross et al., 2017 ; Fausnacht et al., 2020 ; Mayorga et al., 2020 ; Tang et al., 2022 ; Roths et al., 2023 ). Last but certainly not least, and certainly not depicting the entirety of the mechanisms of heat stress associated with cow performance, cows under heat stress conditions have reduced feed intake ( Rhoads et al., 2009 ) and reduced energy substrate adaptability in skeletal muscle, possibly contributing to reduced performance ( Ellett et al., 2025 ).

Given the detrimental impacts of heat stress on cattle performance, health, and welfare, it is important to consider the region-specific variations in climate and implement heat abatement strategies as needed. There are a variety of heat abatement strategies available for dairy calves, heifers, and cows that can be implemented in dairy operations. Multiple studies have tested the effects of different strategies for heat abatement in calves.

For instance, Dado-Senn et al. ( 2020 ) reported a positive association between postnatal heat stress abatement and thermoregulatory responses, feed intake, and health in dairy calves. Montevecchio et al. ( 2022 ) reported a positive relationship between pre-weaning heat stress abatement and lying behavior and healing time (related to disbudding) in dairy calves. The same group also reported positive welfare-related responses and greater wither-height for calves given heat abatement strategies as compared to calves under a simple plywood hutch ( Montevecchio et al., 2022 ).

Benefits for heat abatement in heifers and cows were also reported. For instance, the use of shade from a freestall barn, water soakers, and fans were associated with positive effects on heifer thermoregulation and productivity as compared with heifers kept under freestall shade only ( Davidson et al., 2021 ). Gunn et al. ( 2019 ) described the milk production losses (per cow/year) according to different heat abatement strategies, ranging from minimal (open barn or shading) to intense (air conditioning).

Aside from structural tools to improve heat abatement for dairy cattle, other studies have reported varying results associated with nutritional tools to ameliorate the impacts of heat stress in dairy cows, including chromium supplementation ( Soltan, 2010 ), Saccharomyces cerevisiae supplementation ( Al-Qaisi et al., 2020 ), choline ( Holdorf and White, 2020 ), and other components ( Fabris et al., 2017 ).

The potential of other strategies for heat abatement have been described; for example, a research group from the University of Florida reported that the SLICK haplotype confers thermotolerance in intensively managed lactating Holstein cows ( Dikmen et al., 2014 ). In that study, the authors revealed that cows carrying the SLICK haplotype had lowered rectal temperature and respiration rate across most times of the day compared with cows not carrying the SLICK haplotype.

Although several aspects associated with the SLICK haplotype have not been explored, a recent study reported that SLICK Holstein cows in Puerto Rico exhibited lower body temperatures, greater voluntary solar radiation exposure, enhanced blood supply to the mammary gland, and alterations in genes and metabolites involved in arachidonic acid metabolism at the mammary gland and blood plasma ( Contreras-Correa et al., 2024 ).

Figure 1

(The Author)

Figure 1. Global land-ocean temperature index ( NASA’s Goddard Institute for Space Studies – GISS ).

(The Author)

Figure 2. Projected decadal increases in average annual Heat Stress Frequency between 2000 to 2100 ( Adapted from Gunn et al., 2019 ).

Average Daily THI

(The Author)

Figure 3. Correlation between milk yield and the average daily temperature-humidity index (THI) of the previous week. Circles represent individual observations, and dash line represents simple linear regression. All cows were housed in the same barn equipped with evaporative cooling, and fed similar lactating cow rations (Adapted from Tao et al., 2020 ).

(The Author)

Figure 4. (A) Summary of difference (kg/d) in milk yield in late-gestation heat-stressed cows relative to cooled counterparts (average difference = 3.6 kg/d; 10.3%) and (B) difference (kg/d) in prepartum and postpartum dry matter intakes in late-gestation heat-stressed cows relative to cooled counterparts (prepartum average difference = 1.4 kg/d; 12.7%; postpartum difference = 0.1 kg/d, 0.5%). Adapted from Ouellet et al., 2020 .

(The Author)

Figure 5. (A) Odds ratio and 95% CI calculated for dairy cow mortality during heat wave (HW) and in the 3 not heat wave days (nHW) after the end of heat wave (d 1, 2, and 3 defined as nHWst, nHWnd, and nHWrd, respectively). (B) Odds ratio and 95% CI calculated for dairy cow mortality in relation to the duration of exposure to heat. The duration of exposure was classified as short (1 to 3 heat wave days), medium (4 to 6 heat wave days), long (7 to 10 heat wave days), and very long (>11 heat wave days). Odds ratios are statistically significant when 95% CI does not include the unit (dashed line). Adapted from Vitali et al., 2015 .

(The Author)

Figure 6. Summary of the performance impairments associated with late-gestation heat stress for the dam (1), daughters (F1), granddaughters (F2), and dairy sector (2) reported in a series of study (where ECM = energy corrected milk). Extracted from Ouellet et al., 2020

Factors Affecting Early Pregnancy Loss In Cattle

Tue, 08 Apr 2025 13:20:53 GMT

Open cows are a costly problem for producers. Less cows bred and birthing a live calf means less profit in the hands of producers. Researchers continue to look at factors related to why cows are open.

On a Beef Cattle Institute podcast reproductive physiologist, Bob Larson, DVM and Brad White, DVM, discuss a recent study, based on more than 80 research articles , compiled by researchers at Texas A&M University.

“There’s still a lot of questions about this very early time frame, because it’s hard to research, but one of the things we do know is that when we take a fertile cow and a fertile bull and mate them together, 30 to 40% of the time we don’t end up with a live calf, and most of that loss is in the first 20 to 35 days,” Larson says.

If after the sperm and egg get together and the cells begin to divide, but then don’t progress beyond those first few days to weeks resulting in early pregnancy loss, it is due to issues with the embryo, cow, bull or environment.

Pregnancy loss is a multi-factorial issue and is likely a reflection of inadequacy at the embryonic, maternal, paternal and environmental levels.

(Texas A&M/Lori Hays)

Embryos produce proteins like interferon tau and pregnancy-associated glycoproteins to signal the cow to maintain pregnancy.
“We know some embryos make more interferon tau than others,” Larson explains. “The ability of that early embryo to make those proteins at a sufficient level and timing, has to be quick enough and at the right dose in order to signal to the cow to maintain pregnancy. A cow has a 21-day estrus cycle, and typically will lyse the CL around day 17, so the embryo likely has to send that signal around day 15.”

When we see a cow come back into heat 21 days after she was last in heat, there are usually two possibilities.

“One, she was never mated, or the egg was never fertilized. But it’s also possible, as one of these animals, where the sperm and egg did get together, started some cell divisions, but the embryo didn’t progress far enough or well enough for her to recognize pregnancy and to maintain it, and so she loses it. When the embryo is so small and not yet attached to the uterus, there is no delay in her coming back into estrus,” Larson says.

Cow responses to these embryonic signals are crucial.
Researchers have looked at how well the cow responds to the INFT and glycoproteins the embryos sends and what proteins the cows make in response.

“Different cows produce a different amount, and typically, the more a cow is responding to the embryo, the more likely that pregnancy is to establish and be maintained,” Larson says. “We’re thinking about cells lining the uterus as well as cells in the corpus luteum and in other parts of the body as well. The signals sending from the embryo need to be coming at an appropriate dose and time, and then the cow needs to respond to those signals in a number of different ways.”

Larson says ultrasound can show differences in the follicle sizes cows ovulate.

“If we’re following their follicular waves with an ultrasound, cows that ovulate larger follicles are more likely to end up as a successfully completed pregnancy than smaller follicles,” he says. “We don’t know for certain, but genetics and environment, nutrition, stress, probably are impacting her. So now we’re talking about the cow having an impact on the egg even before it’s fertilized. She might make an egg that is fertilizable, but it isn’t going to be as likely to maintain that pregnancy if that egg isn’t quite as good a quality.”

Schematic of critical factors contributing to pregnancy success and failure.

(Texas A&M/Lori Hays)

Bulls also influence pregnancy through their sperm’s role in placenta development.
“What we’re learning is bulls differ in their ability to influence that embryo to be maintained,” Larson says. “The sperm cell is more involved with producing the placenta than the egg cell is. The early placenta is where all this signaling is coming from. One of the things we know is that embryos from some bulls make more of these pregnancy associated glycoproteins than embryos from other bulls, so bulls are influencing this embryonic signal, but we’re not able to detect pregnancy maintenance differences between bulls with our typical breeding soundness exams.”

Breeding soundness exams look at the cell morphology of the sperm cells, which is a good prediction of the probability of fertilization.

“We know there’s something going on with the male side in the area of not only becoming pregnant, but maintaining that pregnancy, particularly really early in those first few days but no way to measure this in the bull currently,” Larson says.

Environmental factors, including heat and nutrition stress, also significantly impact pregnancy success.
“We know that heat stressed cows don’t express estrus as well — not as frequently, not as long, and the quality the oocyte ovulated is not as good.” Larson says. “Even if the oocyte is fertilized and we go through the first few cell divisions, that early embryo maintenance is less in heat stress. You could see why that would mess up this, fine-tuned connection between the early embryo and the cow.”

These signaling mechanisms rely on, protein secretion and receptor creation, so nutritional deficiencies or a stressful situations, can affect not only the cow becoming pregnant, but also maintaining this pregnancy through this really early critical time, he adds.

More research to identify and measure some of these factors is still needed, however producers can keep in mind their management practices and how they influence pregnancy loss.

Select heifer calves born early in the calving season, as they are more likely to have dams that conceived and maintained pregnancy early.
“Put selection pressure on heifer calves that are born early, because that tells me two things, her dam conceived early and her dam maintained that early pregnancy,” Larson says. “A heifer that is born a little bit later, it’s possible that her dam conceived and then lost it, then conceived and maintained it. If there’s a genetic component, and we think there is, I don’t want to bring that into the herd. So a cow that conceived early in the breeding season and maintained that pregnancy is exactly the type of cow that I want to bring in her daughters into the herd as much as possible.”

Ensure cows are in a low-stress environment with good nutrition around the time of breeding, especially during the critical 12 to 17-day window for maternal recognition of pregnancy.
“I’m going to start with back when the cow is getting ready to calve, because that’s going to set up how quickly she comes back into estrus,” Larson explains. “I want her on a good plane of nutrition. I want her in a housing situation so she’s not in mud; she’s not fighting weather. I want her in as good a low stress environment as possible. So nutrition and housing and then the human activities. If I could do nothing to her during that time frame that would be my best choice keep her as comfortable as possible.”

When moving cows after timed AI, do so either immediately after breeding or wait until at least 45-50 days past breeding, avoiding the critical 7-21 day window.
“Fertilization happens in the oviduct, and that’s a little safer place for the embryo to be than in the uterus,” Larson says. “It’s in that uterine tube for about the first seven days. So that’s probably the safest time to be moving the cattle. Once that embryo goes into the uterus it’s starting to interact between what will become the placenta and the uterine tissue. And they’re not really attached yet, but they’re starting to send signals back and forth, and that’s when I really don’t want to do anything to disrupt that. So basically, if you’re going to do an AI mating, and you need to move the cows, I would probably do it as soon as possible after the mating, or wait till six weeks out before moving them.”

Your next read: Maximize Breeding Success: Utilize Replacement Heifer Exams

Cool Calves Live Longer

Thu, 03 Apr 2025 19:18:50 GMT

The average number of lactations of a U.S. dairy cow currently rests at about 2.8, or around 5 years of age.

That’s a fairly shocking statistic, considering a cow’s natural lifespan can be up to 20 years or more. And, on average, it takes about two full lactations before heifers begin to generate return on investment for their rearing or purchase cost. Given today’s robust heifer values, that time before young cows begin to pay the bills may be even greater.

So, how can we help cows live longer, more productive lives? Researchers at the University of Florida assessed one factor: birth season. They predicted that cows that entered the world during seasons of heat stress would have shorter lifespans. And they were right.

The study, led by researcher Izabella Toledo and published in the Journal of Dairy Science , examined the DairyComp records of more than 10,000 cows in Florida and 8,000 in California that remained alive and productive for more than 5 lactations.

The data were sorted to identify animals born over a period of 10 years (2012-2022) in the cool season (December, January, February, and March) and the hot season (June, July, August, and September). Cows born in the more temperate months of April, May, October, and November were not included in the dataset.

In Florida, 14.5% of cows (1,567) born in the test months were still alive and milking after 5 lactations. Of them, more than double (1,129, or 72%) were born in the cool months compared to the hot months (438, or 28%). In California, 20.4% (1,669) of the dataset made it 5 lactations or longer, with 56.% of them born in the cool months, versus 44% born in the hot months.

The Florida dataset also was analyzed for the number of cows born in the tests months that were dead or sold for beef in the first 4 lactations, and the reasons why. A total of 1,454 were sold and another 238 died. Selling reasons included breeding, foot and leg, digestive, and respiratory issues, along with mastitis.

Significantly more cows born in the hot season (53%) compared to the cool season (47%) were sold for beef.On-farm deaths also were significantly higher for cows born in the hot (54%) versus cool (46%) season.

Toledo and her team concluded that the results give even more credence to the deleterious impacts of heat stress on dairy productivity. Previous studies – many also conducted by University of Florida researchers – have shown that heat stress during late pregnancy affects dams’ milk production in the next lactation, immune function, and calf birth weight.

Further, they have found that calves exposed to heat stress in late gestation had 19% lower milk production in their own first lactations, and even passed that lower milk production potential on to their offspring.

Toledo said the results of the current study suggest a potential two-pronged approach to protecting the productive life integrity of newborn heifers: (1) implement heat-stress abatement measures for dams, including shade, fans, soakers, and misters; and (2) alter breeding decisions to avoid births in seasons of peak heat.

Your Next Read: A New Kind of AI for Dairy Calves

Diagnostics

Your Vet Recommended RT-PCR for Mastitis — Now What?

What RT-PCR Actually Does

How to Interpret a PCR Result

Why PCR Can Still Be Positive When Culture Isn’t

Where PCR Fits and What to Do With It

How to Manage Coccidiosis Risk in Weaned Calves: What Producers Need to Know

The Prognosis

Control and Prevention

Seeing the Whole Elephant: Systems Thinking and Animal Health

Why Looking Closely Isn’t Enough

Systems Thinking: Looking Between the Parts

The Veterinarian as a Systems Navigator

Case Example: Reframing a ‘Simple’ Mastitis Problem

Stepping Back to See the Elephant

Turn Milk Data Into An Early Diagnosis

Milk Yield Deviations

Component Changes: Fat & Protein

Milk Conductivity

Put Milk Measurements Together

5 Sampling Tips for Improved Diagnostics

1. Start With the Right Question

2. Choose the Right Animals To Sample

3. Take the Correct Sample Type and Handle It Properly

4. Record Good Clinical and Herd Information

5. Sample Early and Sometimes More Than Once

How Can We Improve Chuteside Diagnostics?

Why this matters

Chuteside Tools

Practical Challenges

Looking Ahead

Texas A&M Researchers Study Diet’s Impact On Salmonella Prevalence In Cattle

Taking A New Approach

Continuing The Investigation

Bull Tests Positive for Brucellosis: Herd Quarantined and Investigation Continues

Previous Brucellosis Detection

What is Brucellosis?

Three Strategies to Prevent Weaning Health Woes

1. Develop a Vaccination Strategy to Boost Immunity.

2. Don’t Combine Stressful Procedures.

3. Observe for Illness Indicators.

Get BQA Certified

Don’t Waste Feed: Let Manure Scores Guide Cattle Nutrition

What do the manure scores look like and mean?

How can you improve manure scores?

When should you gather manure scores?

Risk Factors Associated with BRD in Preweaned Calves

Research Findings

There’s a Lot of Info in That Little TSU

Then There Are The Bulls

3 Livestock Skin Concerns to Watch For This Summer

Photosensitization: Severe sunburn caused by toxic plants

Rain rot: Crusty skin infections after wet weather

Summer sores: Fly-transmitted wounds that won’t heal

Healthy herds with expert support

Kansas Beef Producers Beware: A Case of Theileria Found

Success From The Start: Calf Health Starts Before Birth

Protect the Herd: The Signs to Watch for Calf Pneumonia

Signs of Pneumonia

Tips for Prevention

Veterinary Pharmaceutical Solutions Unveils Innovative Pharmacy Expansion

Beef Producers Be Aware: Dangerous Asian Longhorned Tick Continues Migrating West

What does it look like?

What are the health risks?

How to Tackle Ticks

Two Key Tips to Stop Persistently Infected Calves Before They Start

1 Fulton RW, Briggs RE, Ridpath JF, et al. Transmission of bovine viral diarrhea virus 1b to susceptible and vaccinated calves by exposure to persistently infected calves. Can J Vet Res 2005;69(3):161–169.

2 Perkins-Oines S, Dias N, Krafsur G, et al. The effect of neonatal vaccination for bovine respiratory disease in the face of a dual challenge with bovine viral diarrhea virus and Mannheimia haemolytica. Vaccine 2023;41(19):3080–3091.

3 Fulton RW, Cook BJ, Payton ME, et al. Immune response to bovine viral diarrhea virus (BVDV) vaccines detecting antibodies to BVDV subtypes 1a, 1b, 2a, and 2c. Vaccine 2020;38(4)4032–4037.

Fine-Tuning First-Lactation Performance with Smarter Data Management

First-lactation learning curve

Data-driven results

Better grouping, better gains

About Nedap

Unlocking Success with Cow Herd Health Metrics: A Scorecard Approach

National Mastitis Council Plans Regional Meeting, Registration Now Open

AABP Annual Conference will 'Focus on Value'

Streamline Spring Cattle Processing with These 3 Stress-Reducing Steps

The Effects of Heat Stress on Dairy Cattle Development, Health and Performance

Factors Affecting Early Pregnancy Loss In Cattle

¹Fulton RW, Briggs RE, Ridpath JF, et al. Transmission of bovine viral diarrhea virus 1b to susceptible and vaccinated calves by exposure to persistently infected calves. Can J Vet Res 2005;69(3):161–169.

²Perkins-Oines S, Dias N, Krafsur G, et al. The effect of neonatal vaccination for bovine respiratory disease in the face of a dual challenge with bovine viral diarrhea virus and Mannheimia haemolytica. Vaccine 2023;41(19):3080–3091.

³ Fulton RW, Cook BJ, Payton ME, et al. Immune response to bovine viral diarrhea virus (BVDV) vaccines detecting antibodies to BVDV subtypes 1a, 1b, 2a, and 2c. Vaccine 2020;38(4)4032–4037.