Cattle Reproduction

What the Semen Microbiome Reveals About Bull Fertility

Fri, 24 Apr 2026 17:05:33 GMT

Bacteria in bull semen have long been viewed as a problem to manage. New research suggests they may also be a signal to interpret. A recent study published in Animals from the St. Petersburg State University of Veterinary Medicine links the semen microbiome to fertility outcomes, raising a different question: What does that microbial profile reveal about the bull itself?

How Bacteria in Bull Semen Have Traditionally Been Managed

For years, the focus has been on controlling bacterial populations in semen to protect sperm function and prevent disease transmission. Hygiene protocols, extender formulation and antibiotic inclusion all reflect that priority.

This approach has been effective for preserving semen quality and limiting biosecurity risks. It has also shaped how fertility is evaluated. Motility, morphology and concentration remain the primary metrics, each focused on the sperm cell itself.

What this framework largely excludes is the biological environment surrounding those cells.

What a New Study Shows About the Bull Semen Microbiome

The new work set out to characterize that missing layer. Using 16S rRNA sequencing, the authors profiled the semen microbiome across bulls, quantifying both microbial diversity and the relative abundance of bacterial taxa.

Rather than treating bacteria as background noise, the study evaluated microbial communities as a variable of interest. The analysis identified dominant phyla within bull ejaculates, including Proteobacteria, Firmicutes, and Actinobacteria, with measurable variation between individuals.

The study then examined how those microbial patterns aligned with fertility outcomes. The result was not a single causative organism, but a set of associations between microbial profiles and reproductive performance.

They found bulls with excellent quality semen had a higher abundance of Actinobateriota: from around 2% of the microbiota of low-quality sperm to around 14% in excellent-quality sperm. Further, Bacteriodes fagilis was detected in 75% of samples of low-quality sperm, while it was only in 20% of excellent-quality sperm samples.

It is important to note the study did not test whether bacteria influence fertilization directly, but whether the microbiome tracks with differences in sperm quality.

Is the Semen Microbiome Random or Structured?

One of the most consistent findings across studies is that the semen microbiome is not random.

The dominance of a small number of bacterial phyla observed in the Animals study aligns with earlier work. For example, Cojkic and colleagues reported bull semen microbiota are structured and repeatable, with Proteobacteria often comprising a large proportion of total abundance.

At the same time, variation between bulls appears to be meaningful. In the Animals study, microbial composition differed across individuals, and those differences aligned with fertility outcomes. Similar patterns have been reported by Koziol and colleagues who found significant differences in microbial communities between bulls with satisfactory versus unsatisfactory semen quality.

Taken together, these findings support a shift in interpretation. The semen microbiome behaves less like noise and more like a measurable, variable characteristic.

Does the Semen Microbiome Affect Fertility or Reflect It?

The central question is not whether the microbiome is associated with fertility. Multiple studies now support that conclusion. The question is what that association represents.

There is a plausible case for biological interaction. Work from the University of Georgia reported associations between microbial composition and sperm function, including motility and mitochondrial activity, with statistically significant differences observed between microbial profiles.

These findings suggest microbial communities could interact with sperm physiology under certain conditions.

However, the alternative explanation remains equally important.

Microbial composition has also been shown to shift with external and host-related factors. Studies from North Dakota State University and the Swedish University of Agricultural Sciences have documented changes in semen microbiota associated with age, environment and management conditions, with measurable variation in dominant taxa across groups.

These patterns indicate the microbiome may reflect the broader physiological and environmental context in which sperm are produced and handled.

Taken together, the available evidence supports a cautious interpretation: The microbiome may not be acting on fertility. It may be reporting on it.

A Missing Layer in Bull Evaluation

If that interpretation holds, the implications are practical.

Current fertility evaluation tools focus on the sperm cell. Motility, morphology and concentration provide valuable information, but they offer limited insight into the biological context surrounding those cells.

The semen microbiome introduces a potential additional layer. By capturing aspects of the reproductive tract environment and systemic conditions, microbial profiles may help explain variability that is not accounted for by conventional metrics.

Emerging work supports this direction. Integrative approaches combining microbiome, genomic and metabolic data have reported improved prediction of fertility-related outcomes compared to single-measure approaches.

At the same time, these approaches remain in early stages of development and are not yet part of routine evaluation.

Before the Semen Microbiome Can be Used in Practice

Translating microbiome data into practical tools will require further refinement. Across studies, reported microbial compositions vary depending on sampling technique, sequencing platform and analytical approach, making it difficult to define consistent reference ranges or thresholds for interpretation. It also remains unclear whether diversity metrics, specific taxa or broader community structure will prove most informative for evaluating fertility.

At the same time, none of this diminishes the importance of bacterial control in semen processing. Hygiene and antibiotic use remain essential for maintaining semen quality and preventing disease transmission. However, research indicates bacterial populations can persist despite these measures, with detectable microbial communities present even after standard processing and antibiotic inclusion.

Taken together, these findings point to a subtle shift in perspective. For years, the focus has been on controlling bacterial populations in semen. Emerging research suggests they may also be worth interpreting. The value of the semen microbiome may not lie in changing fertility outcomes, but in helping explain them.

Early Embryonic Loss in Cattle: How TKDP Research Hopes to Improve Pregnancy Success

Fri, 17 Apr 2026 17:26:05 GMT

Early embryonic loss in cattle can occur even after a cow conceives and signals pregnancy — often before anyone knows she was ever pregnant.

At Purdue University College of Veterinary Medicine, researchers are working to understand why. A new project led by Viju V. Pillai is focused on decoding the earliest biological signals that determine whether a pregnancy establishes or fails.

This is not a failure of timing or technique. The most consequential losses in cattle reproduction are happening earlier than most management decisions can reach, at a stage where biology either stabilizes the pregnancy or quietly resets the system.

Why do cows lose pregnancies early?
Early embryonic loss in cattle is often driven by failed communication between the embryo and the uterus during the first two weeks of gestation. Current research suggests proteins such as TKDPs may play a key role in this process, though their exact function is still being defined.

Early Embryonic Loss in Cattle: The Hidden Driver of Reproductive Inefficiency

Early embryonic loss in cattle is not a rare event. It is a defining inefficiency in modern cattle production. Fertilization rates in cattle are typically high, often exceeding 85% to 90% under well-managed conditions. Even so, an estimated 30% to 50% of embryos fail to survive the first month of gestation, highlighting that the primary bottleneck is not conception, but early embryonic survival.

Pregnancy losses often occur before producers have any opportunity to respond. These failures increase breeding costs, extend calving intervals and reduce overall productivity, making them a major economic concern across both beef and dairy systems.

The economic impact is substantial across U.S. beef and dairy systems, even if it is rarely captured in a single number. The scale is well recognized, but the underlying cause has remained far less clear.

For years, reproductive management has focused on improving breeding success and detecting pregnancy earlier. That approach assumes the key event is conception. Research efforts like the one underway at Purdue are shifting that focus toward a more fundamental question: What allows a pregnancy to hold in the first place?

A Focus on TKDP Proteins: Understanding Early Pregnancy Loss in Cattle

The Purdue-led project is supported by a four-year, $650,000 New Investigator award from the USDA National Institute of Food and Agriculture, with a focus on the earliest stages of pregnancy — before conventional diagnostics can detect success or failure.

During this narrow window, the embryo must establish a functional relationship with the uterus. Researchers describe this process as a molecular handshake — a coordinated exchange of signals that determines whether the pregnancy progresses or fails.

At roughly 14 days after conception, the embryo is still microscopic, yet it must signal clearly enough to prevent the uterus from returning to a normal estrous cycle. If that signal falters, the pregnancy ends before it effectively begins.

The project centers on a family of ruminant-specific proteins known as trophoblast Kunitz domain proteins (TKDPs). These proteins are being investigated for their potential role in regulating early embryo-maternal communication, making them a focal point for understanding early embryonic loss in cattle.

TKDPs Versus PAGs: What Determines Pregnancy Success in Cattle?

Pregnancy-associated glycoproteins (PAGs) have long served as the industry’s primary biomarker for pregnancy detection in cattle. Their reliability has made them a cornerstone of blood-based testing programs. PAGs confirm a pregnancy exists, though only after key biological steps have already occurred.

TKDPs appear to function earlier in the sequence. Current research suggests they may be involved in early embryo-maternal signaling events, particularly within trophoblast cells that later form the placenta.

These proteins are being investigated for their potential role in establishing the conditions required for pregnancy success:

Supporting initial attachment between the trophoblast and uterine lining
Regulating maternal immune tolerance to embryonic tissue
Coordinating early signaling pathways between embryo and uterus

PAGs tell you a pregnancy exists. TKDPs may help determine whether it was ever viable.

How Researchers Study Early Pregnancy in Cattle: Trophocysts and CRISPR

Studying early embryonic loss in cattle directly presents a fundamental challenge. The biology is too early, too small and too transient to observe in a controlled way. That constraint is driving the adoption of new experimental systems.

Researchers are using three-dimensional culture systems and embryo-like structures known as trophocysts to model early placental development and signaling outside the animal. These systems allow controlled observation of how early pregnancy signals are generated and maintained.

Gene editing with CRISPR-Cas9 enables targeted disruption of specific TKDP genes within these models. Removing individual components of the signaling network allows researchers to observe how breakdowns in that molecular exchange may contribute to pregnancy loss.

What Early Embryonic Loss Means for Veterinarians, Producers and One Health

The key shift this work hopes to provide is conceptual. Early embryonic loss in cattle is no longer viewed solely as a downstream outcome of management decisions. It is increasingly being investigated as a failure of early biological signaling.

Management factors still matter, though their role becomes clearer through this lens. Heat stress, nutritional imbalances and early post-breeding conditions influence the molecular environment in which this signaling occurs.

The long-term goal is practical. Identifying the biological mechanisms behind early pregnancy loss could eventually support strategies that improve reproductive efficiency and herd productivity.

The implications extend beyond cattle. The biology underlying early pregnancy is highly conserved across species, with processes such as immune tolerance and embryo-maternal communication following similar principles in both livestock and humans.

Insights into these early signaling pathways may contribute to broader reproductive research, aligning with One Health efforts that connect animal and human health.

Why Getting Cows Bred Earlier Pays Off More Than You Think

Mon, 06 Apr 2026 15:06:25 GMT

Timing is one of the most powerful and underleveraged tools in cow-calf production. While genetics, nutrition and health protocols often take center stage, both research and field experience point to a simpler truth: When cows get bred matters just as much as whether they get bred at all.

In a recent conversation, Jacques Fuselier, manager of cattle technical services at Merck Animal Health, reinforced what many veterinarians and producers have observed for years: Cows that calve earlier in the season consistently outperform their later-calving herdmates. They wean heavier calves, rebreed more efficiently and generate greater returns per head. But the real story starts earlier in the cycle.

Calving Timing Starts With Breeding Timing

The advantage of early calving is well established. Earlier-born calves have more days to grow before weaning, often align better with peak forage availability and enter the market at a weight advantage. Their dams also have more time postpartum to resume cyclicity and conceive again.

As we know, calving timing is not random; it reflects when cows conceive during the breeding season.

As Fuselier explains, “The goal is to get as many cows pregnant as you can in the first 21 days.”

The more cows that conceive early, the more calves that are born early, and the more consistent and productive the system becomes.

Uniformity Is the Economic Engine

The biological advantages of early calving translate directly into economic returns.

“When calves are sold, they are sold by the pound, so pounds matter,” Fuselier says. “If you could come up with a way to not do a lot more to your herd — but whatever you do make it better to where you have more calves born early in a calving season — you’ll end up with a heavier, more uniform calf crop and weaning, therefore being more profitable.”

Uniformity is one of the most important drivers of value in a calf crop. Calves that are similar in age and weight are easier to manage, easier to market and often command stronger prices. A tighter calving window produces a more consistent group, improving both operational efficiency and sale outcomes.

The Hidden Cost of a Long Breeding Season

“When the breeding season is strung out, the calving season gets strung out. So, the uniformity of your herd goes down,” Fuselier says. “Plus, the time for those cows, after calving, for their uterus to repair, to start cycling again and to be able to get bred again is important. If there’s an overlap of when bulls go out and when those cows are recovering from calving, you just perpetuate that cycle.”

Late-calving cows have less time to recover before the next breeding season, making them more likely to breed late again or fall open. Over time, this creates a persistent tail of late-calving animals that erodes herd performance and profitability.

Small Timing Shifts, Big System Changes

Even modest improvements in early breeding can create meaningful downstream effects.

“By shortening the number of days that cows are calving, it allows you to focus your labor force better and for a shorter period of time, instead of having to split duties over multiple months,” Fuselier says.

This improved labor efficiency complements the biology and economics of a tighter calving window. In an environment where labor is increasingly limited, concentrating calving into a shorter, more predictable period can significantly reduce management strain.

A Tool to Move the Herd in the Right Direction

Long-term strategies like genetic selection and heifer development remain essential, but there are also practical tools that can help shift breeding timing more immediately.

One example is the use of prostaglandin-based synchronization products, including the cloprostenol injection Estrumate , at or shortly after bull turnout. This product induces luteolysis in cycling cows, encouraging more animals to return to estrus early in the breeding season and increasing the proportion bred in that critical first 21-day window.

“With very little effort, just the addition of another injection, you can start moving that calf crop up and tightening the calving window by having more born earlier in the calving season than later in the calving season. You end up increasing the uniformity of your calf crop,” Fuselier explains.

In natural service systems, where synchronization options are often more limited than in artificial insemination-based programs, this type of approach offers a relatively simple way to influence breeding distribution without significantly increasing labor or complexity.

The Compounding Effect Across Generations

The impact of early breeding extends beyond a single season.

“Heifers born to cows in the first part of that calving season will end up reaching puberty earlier and breeding earlier. You try to build the herd with cows that have their biological clocks that way. So, generation after generation after generation, you’re seeing it,” Fuselier says.

This creates a powerful compounding effect. Early-born heifers are more likely to become early-breeding cows, gradually shifting the entire herd toward improved reproductive efficiency over time. Few management decisions influence both short-term performance and long-term herd development so directly.

Early calving gets the attention, but early breeding is the lever that makes it happen.

Bulls Remain the Weak Link in Trichomoniasis Control

Thu, 02 Apr 2026 20:01:59 GMT

A breeding season can appear routine until the pregnancy check tells a different story. Conception rates fall short of expectations, cows return to heat off schedule and open females begin to stack up. What looks like a management issue is often something far more specific and far more costly.

Across the U.S. beef industry, bovine trichomoniasis continues to drive significant reproductive loss. Economic modeling published in the Journal of Agricultural and Applied Economics shows even modest reductions in disease prevalence can produce meaningful gains, with losses largely tied to fewer calves born and extended calving intervals. In affected herds, pregnancy rates commonly fall by 20% to 40%, and the financial impact compounds quickly over time.

At the center of it all is a consistent and often underestimated risk: the bull.

The Biology That Drives the Problem

Trichomoniasis, caused by the protozoan Tritrichomonas foetus, is a venereal disease transmitted during natural breeding. While both sexes are involved in transmission, the disease behaves very differently in cows versus bulls.

Most cows clear infection within two to four months. However, that clearance comes after early embryonic loss, often delaying conception by 30 to 90 days and stretching the calving season.

“The cow can mount a short-term immune response and clear the infection. She can eventually rebreed and carry a calf to term, but she’s going to lose that initial pregnancy that she had,” said Jennifer Koziol, associate professor of food animal medicine and surgery at the School of Veterinary Medicine at Texas Tech University on a recent episode of DocTalk .

Bulls, by contrast, create the long-term problem.

“The bull is a silent carrier because he doesn’t have any symptoms. He’s just going to spread it from female to female during breeding,” Koziol says.

A recent review published in the International Journal of Molecular Sciences explains why. The organism colonizes the preputial crypts, where immune clearance is limited. As bulls age, these crypts deepen, increasing the likelihood of persistent infection. Once infected, bulls typically remain carriers for life.

This biological mismatch is what makes control so difficult. The cow eventually clears the infection, but only after reproductive loss. The bull never clears it and continues to transmit it.

Recognize the Pattern in the Herd

Trichomoniasis rarely presents as a single obvious sign. Instead, it emerges as a pattern of reproductive inefficiency that can be easy to misinterpret early on.

“We see low pregnancy rates ... cows returning to estrus at intervals they shouldn’t, we can see abortions, ” Koziol says, discussing the big indicators that something is wrong in the herd.

These clinical signs reflect disruption during early gestation. Most losses occur within the first 60 days of pregnancy, often before confirmation, which is why the problem may go unnoticed until later in the season.

The full impact often becomes clear at pregnancy check.

“We go out and do pregnancy checks, and we’re only getting 50% to 60% conception rates. That’s a pretty terrible day when you’re just saying open, open, open,” Koziol says.

In heavily affected herds, calf crops can drop into the 50% to 70% range, well below the 85% to 95% typically expected in well-managed operations. At that point, the biological effects have already translated into economic loss.

“This is not an individual animal problem — it’s a herd-level problem. Once we find a positive, we have to start thinking about the entire bull battery and the whole herd,” Koziol says.

Epidemiologic studies, including one published in Theriogenology, show herd structure and management decisions drive disease persistence. The use of older bulls, multi-sire breeding systems and the introduction of untested animals all increase risk. Even a single infected bull can maintain transmission within a herd, particularly when multiple bulls are breeding simultaneously.

How Trich Continues to Spread

Despite long-standing awareness, trichomoniasis persists because of how easily it moves between herds and how difficult it can be to detect with absolute certainty.

“A lot of times the way a herd gets infected is if a neighbor bull breeds cows, then your bull breeds behind him and becomes positive. That’s why testing before and after the breeding season is so important,” Koziol says.

Fence-line contact, shared grazing and commingling all create opportunities for exposure. Diagnostic research, including recent work on evolving testing approaches, highlights another challenge: no single test guarantees detection. While PCR has improved sensitivity compared to traditional culture, false negatives can still occur due to sampling technique, organism load or intermittent shedding.

For that reason, Koziol suggests repeated testing should be used to improve confidence in bull status, specifically at the start and end of the breeding season. Even virgin bulls should be screened.

“We don’t trust a virgin-status bull,” Koziol warns. “When we buy a bull, we want to test him and know that he’s negative.”

No Treatment, Only Prevention

A defining limitation of trichomoniasis control is the absence of an effective treatment for bulls. Prevention depends on verification, not assumption. Bulls must be tested prior to introduction, regardless of perceived risk.

Once a bull tests positive, removal from the breeding population is the only effective option. There is no reliable method to eliminate infection.

Vaccination plays a supportive role, primarily in cows, where it can reduce the severity and duration of infection. While experimental vaccine trials in bulls have been performed, they have not yet produced a practical solution for eliminating the carrier state. As a result, vaccination should be viewed as an adjunct, not a replacement for testing and culling.

The Economics of Getting it Wrong

For producers weighing the cost of testing, the comparison is straightforward.

“The test costs about $45 to $60 depending on the state. That’s pretty economical compared to losing multiple $2,000 cows,” Koziol says.

Economic analyses reinforce this at scale. Losses are driven not only by fewer calves, but also by extended calving seasons, reduced uniformity and increased replacement pressure. Even relatively small drops in pregnancy rate can have a measurable impact on profitability, particularly in larger herds.

Where Control Succeeds or Fails

Operations that successfully control trichomoniasis tend to follow a consistent set of practices:

Test all bulls before and after each breeding season
Remove positive bulls immediately
Minimize commingling and fence-line exposure
Verify the status of all incoming breeding animals

When these steps are applied consistently, trichomoniasis becomes a manageable risk. When they are skipped, even once, the disease can establish and persist.

Trichomoniasis is not a new disease, and it is not a mysterious one. Its persistence is tied to a single, well-defined weakness in herd management.

Bulls remain the weak link because they are both the reservoir and the vector, carrying infection silently and indefinitely. The visible losses show up in the cow herd, but the source remains easy to overlook. Control depends on consistent use of the tools already available.

Trichomoniasis erodes reproductive performance quietly, one breeding at a time. In most cases, the problem begins — and continues — with the bull.

Preparing for Winter Calving and Breeding Success

Wed, 26 Nov 2025 12:33:29 GMT

As winter calving approaches, veterinarians and producers alike begin the ritual of assembling calving kits, checking facilities and brushing up on best practices. To help refine these preparations, Dr. Adrian Barragan, associate research professor and Extension veterinarian at Penn State University, recently shared practical, research-grounded guidance on dystocia management, postpartum risks and strategies to set cows up for breeding success on an episode of “ The Beef Podcast Show .”

His message centered on one theme: Timing and monitoring matter more than anything else.

Early, Accurate Monitoring for Calving Success

Barragan emphasizes calving involves two patients: the dam and the calf. Monitoring needs to reflect the needs of both.

“One thing that is key when it comes to the calving season is having proper monitoring of calving progress. That is what is going to determine if the calf is going to survive and how bad it’s going to be afterwards for the dam,” Barragan says. “The earlier we can identify that the cow needs assistance the better. However, if we intervene too soon, that can also have negative effects on the dams.”

Cows must be allowed to complete dilation before assistance begins. Pulling a calf before full dilation can create severe trauma to the reproductive tract, setting the dam up for a cascade of postpartum complications.

Because beef cows aren’t watched as closely as dairy cows, Barragan recommends beef operations adjust management to close the monitoring gap. Simple steps like maintaining smaller calving pens near the home site, bringing close-up cows into more observable groups and checking them at least every three hours can dramatically improve outcomes.

Once labor begins, marked by the appearance of the amniotic sac or hooves though the vulva, progress should be seen every 15 or 20 minutes. If within 30 to 60 minutes you see no progress with the animal, it’s time to move her into a chute to see what’s going on.

Postpartum Priorities

Compared with dairy herds, postpartum disease in beef cattle is rare.

“We have retained placentas, and we have metritis. However, the incidence is very very low,” Barragan says. Nationally, retained placenta and metritis together occur in only about 0.3% of beef cows.

Even so, cows identified as high risk should be monitored 24 to 48 hours postpartum, even if they appear fine immediately after delivery. During that time, animal care professionals should confirm:

The placenta is expelled within 24 hours
The cow is standing, eating and drinking normally
No early signs of downer cow syndrome appear
The calf is nursing and remains vigorous

Calves also require careful management, especially if the dam is having issues.

“I always recommend to not keep the calf with the cow, because the cow … might step on the calf and injure that animal,” Barragan advises. “You have to protect the calf. If the calf isn’t going to survive, then what’s the point of having that cow?”

Managing the Calving to Conception Transition

Once calving is wrapped up, producers quickly turn toward breeding, but Barragan stresses that cows need a true voluntary waiting period before entering any breeding program. This allows time for uterine involution, for metabolic balance to return and for the reproductive system to restart cycling. Moving cows into breeding groups too early can delay conception or cause them to fall further behind.

If a cow is coming out of a difficult calving, they might take longer to resume normal estrous cycles; these animals are often late or repeat breeders. But also be aware of any larger scale breeding issues within the herd.

“It’s one thing if one cow isn’t getting bred, but if your whole herd is taking several cycles to get bred, that’s a clue that we need to evaluate what’s going on and do some deeper diving,” Barragan says.

Even in herds with low postpartum disease rates, Barragan reminds producers to watch for cows that simply don’t bounce back. Poor appetite, sluggish behavio, or delayed return to normal mothering behaviors can signal underlying issues that could affect fertility weeks later. Early, supportive treatments including fluids, electrolytes or additional monitoring can shorten that recovery window and improve breeding performance.

Preparation, Patience and Precision

Good calving outcomes hinge on practical, attentive management. Monitoring cows often enough to catch the start of labor, resisting the urge to intervene too early and giving extra time and space to cows recovering from hard calvings all play central roles. The first 24 to 48 hours after birth remains a critical window. Careful attention to the dam’s appetite, behavior and placenta expulsion, and to the calf’s strength and nursing, creates a solid foundation for the next breeding season.

Healthy cows are the true engine of reproductive success. Whether a producer relies on bulls, AI or simple synchronization, none of these tools can overcome poor recovery, delayed cycling or undetected postpartum issues. The best outcomes come from knowing which cows need more support, allowing them time to heal and making intentional decisions. Patience and observation can lead to improved fertility, tightened calving windows and a herd that is set up well for the next cycle.

Can We Shape Calves Before Birth?

Thu, 20 Nov 2025 15:35:48 GMT

What if the most powerful determinant of a calf’s lifetime performance isn’t the genetics you select or the ration you feed, but the environment that calf experienced as a one-cell embryo? As research accelerates, developmental programming is becoming one of the most promising frontiers in cattle reproduction.

For two decades, the beef and dairy industries have focused relentlessly on improving fertility — and it worked. Conception rates rose, days open stabilized and the long slide in reproductive performance reversed. With conventional reproductive efficiency nearing a functional ceiling, scientists are shifting attention upstream, where the environment itself may program the future trajectory of the calf.

It’s well known that a resulting phenotype represents the consequence of genotype and environmental interactions. The performance of an animal depends on the genes they inherited, how much feed they get, whether they get sick, whether it’s hot or cold, and a plethora of other environmental factors.

“We’ve made tremendous progress in optimizing the environment that those animals are raised in by providing the best nutrition, the best housing, the optimal photo period and treating disease with pharmaceuticals to optimize phenotype,” says Peter Hansen of the University of Florida. “But we usually do that after the animals are born. We don’t really think too much about what is happening to those animals when they’re embryos or when they’re fetuses or even when the germ cells are being produced.”

Evidence of Developmental Programming

Recent work has shown us the environment of the mother and the early embryo can affect the postnatal phenotype of that embryo. The environment of the fetus can affect what kind of calf it becomes.

When embryos are produced in vitro, they are put in an artificial medium. Under normal protocols, this culture medium is choline-free. Choline is a methyl donor that may factor into the one-carbon metabolism of bovine embryos. In the uterus, choline is present at millimolar concentrations.

Work led by Eliam Estrada-Cortes in Dr. Hansen’s lab investigated the effect of culturing bovine embryos with or without choline. They found choline cultured embryos resulted in calves that were heavier at weaning with altered muscle DNA methylation.

“We’ve done this experiment three times, and each time the choline calves weigh more than the calves without choline. And that goes all the way through to slaughter,” Hansen says. A nutrient present (or absent) in the culture dish during critical development time can make a big difference.

The condition of the fertilizing bull can also affect embryonic development and quality. Arslan Tariq from the University of Florida investigated the effect of bull overnutrition on fertility, finding heavier bulls produced semen that delayed embryonic development and decreased embryo quality, without changes to sperm motility or fertilization rate.

Historically, seminal plasma is removed from sperm for artificial insemination as it contains elements that can be detrimental during storage. That being said, seminal plasma modulates the maternal environment in a significant way, impacting the establishment and maintenance of pregnancy. As a part of her PhD thesis, Gabriela Macay at the University of Florida evaluated the reproductive, health and production performance of female offspring conceived in the presence of seminal plasma. These animals had increased birth weights, increased milk yield and had greater persistence in the herd compared to controls.

“What we now know is the environment of the mother that the early embryo is in can affect the postnatal phenotype of that embryo. The environment of the fetus can affect what kind of calf it becomes,” Hansen says. “And the environment of the bull.”

How Does This Affect Reproductive Management?

Developmental programming shifts reproductive management from a focus on achieving conception to a broader view of how early-life conditions shape an animal’s long-term health, productivity and resilience. This expands the veterinary role from problem solver to long term system designer who helps producers make choices that shape herd-level outcomes years down the line.

The next revolution in cattle reproduction may come from understanding the earliest biological environment that determines how a calf learns to grow, metabolize and perform.

Every Cycle Counts: Energy, Fertility and Profit in the Beef Herd

Mon, 22 Sep 2025 13:58:02 GMT

With calf prices sitting around $4 per pound, there has never been a better time for beef producers to prioritize reproductive performance. As Ted Perry, beef cattle technical services with Purina Animal Nutrition, points out, every missed heat cycle isn’t just a lost pregnancy, it’s 50 lb. of lost calf growth.

“When you look at the profitability of cow-calf operations in previous years, if we could make $100 per cow per year, that was a big deal,” Perry says. “Now with these prices, we could potentially lose $200 per heat cycle.”

That kind of economic pressure has many veterinarians and producers re-examining how to tighten up breeding windows, improve conception rates and, ultimately, get more calves on the ground early in the calving season. Even small improvements in conception rates or tighter breeding windows add up quickly across a herd. Shifting just a few calves earlier in the calving window can offset the cost of nutritional interventions many times over.

Why Energy Balance Matters

The foundation of reproductive success in beef cows is energy balance. Cows that enter the breeding season in poor condition often take longer to return to estrus, reducing the likelihood they’ll conceive in the desired breeding window. Negative energy balance is common after calving, particularly in young cows still growing themselves. This can result in delayed estrus, weak heat expression and lower conception rates. Perry emphasizes managing body condition score (BCS) is non-negotiable.

“Make sure the cows are pushing that BCS of 6, and make sure the bulls are pushing that,” he says.

Energy status influences not only whether a cow cycles, but also egg quality and embryo survival. Research consistently shows cows with adequate energy reserves at breeding conceive earlier, stay pregnant more consistently and wean heavier calves. Simply put, managing energy status sets the stage for reproductive success.

Research on Energy Support

Purina has been evaluating nutritional strategies to support reproductive performance under today’s market conditions.

In a two-year study involving 164 beef cows, animals fed a new technology, CX8, beginning 30 days prior to breeding through 90 days after showed higher first service conception rates from artificial insemination compared to controls, with results improving in the second year.

The mechanism?

“There are multiple additives, such as yeast, to support rumen health, increased levels of trace minerals and phytogenic compounds providing antioxidant properties to support performance,” Perry explains. “However, with multiple components, you can override the system. You can end up with the two components canceling each other out. That’s been a huge part of our research: making sure that everything we use is complementary — one plus one should equal two and a half.”

The approach also accounts for rumen efficiency. By balancing rumen function with the right mineral and additive support, cows can extract more energy from their diets, channeling that into reproductive success.

At the same time, bulls also need careful nutritional management. Perry says semen production depends heavily on BCS.

“If [bulls] are too thin, they’re not going to produce enough semen … [If] we get them too fat during the rest period, then we put them out and they’re running and chasing everybody to get bred. What happens to their body condition? They’re dropping. They’re in starvation mode. They’re not going to produce semen,” he says.

Because semen maturation takes about 60 days, Perry recommends ensuring bulls are at BCS 6 approximately 120 days before turnout — essentially by Christmas if breeding starts in May.

Another area of interest is early embryonic loss. While the work is ongoing, Perry notes artificial insemination and embryonic transfer practitioners are reporting potentially lower rates of early embryo death in herds receiving nutritional support during breeding, potentially boosting conception success even further.

Build the Foundation

Still, Perry cautions no supplement can fix a fundamentally weak nutrition program.

“You’ve got to have the building blocks in place to start with,” he says.

Veterinarians and producers can work together on these building blocks to improve reproductive outcomes in a number of ways:

Monitor and manage BCS. Aim for cows to calve at a BCS of 5 to 6. Cows in this range are more likely to cycle and conceive on schedule.
Make a nutrition plan. Design mineral and feeding programs that balance energy needs with reproductive goals.
Prioritize young and thin cows. These groups are most vulnerable to energy shortfalls and reproductive delays.
Align nutrition with breeding seasons. Matching feed quality and supplementation to peak demand periods pays dividends in conception rates.

Once these fundamentals are in place, advanced nutritional strategies — whether CX8Additive Technology or similar products — can provide an extra push in conception rates.

Takeaways

For veterinarians, the message is clear: reproduction is both a biological and an economic conversation. Helping producers link nutrition and reproduction not only improves herd health, but also directly impacts profitability.

For producers, today’s calf market represents both an opportunity and a challenge. As Perry puts it, with calf prices so high “now is the time that you find out what works at your ranch.”

Fat Matters: How Back Fat Impacts Bull Fertility

Wed, 10 Sep 2025 18:36:03 GMT

A bull’s job is to breed cows. From a fertility standpoint, a bull should be sound and ready to go to work each breeding season.

To better understand how a bull’s condition affects his soundness, a recent research project at the University of Georgia (UGA) looked at the relationship between a bull’s subcutaneous backfat thickness and its semen quality .

“Over conditioning is very common within the seedstock world, and we’re interested in understanding to what extent that over conditioning or increased subcutaneous back fat thickness may have an influence on that bull’s fertility,” says Molly Smith, a UGA doctorate student.

She says the project included more than 700 bulls — a combination of Angus and Sim-Angus crosses from three different bull development programs. The research process included two key steps: a carcass ultrasound and a breeding soundness evaluation (BSE).

The study categorized bulls into three groups based on their subcutaneous backfat thickness, using 10% and 20% thresholds.

When examining semen characteristics, Smith says they found some intriguing results.

“We saw no differences in the amount of motility, but we did see differences in morphology,” Smith explains.

Morphology refers to the shape, size and structure of the sperm. Sperm motility is how it moves.

Specifically, bulls in the top fat thickness categories showed concerning semen quality characteristics.

“Those bulls that were in the top threshold actually had a less percent, a less amount of normal sperm cells and a greater amount of primary and secondary abnormalities,” Smith says.

BSE Impact

Pedro Fontes, UGA associate professor, recently visited with Smith about her project during a “UGA Beef Tips” podcast .

He asked Smith if the backfat affected the bull’s ability to pass the BSE.

Smith says, “Bulls that have a greater than about 0.5" of subcutaneous back fat thickness had a greater probability to fail their breeding soundness evaluation.”

Quantifying this, she adds, “10% of them failed their breeding soundness evaluation, which is greater than two times the bulls that were in our other two categories.”

Fontes clarifies the failures were specifically related to semen quality, excluding other potential reasons for failing a BSE.

“Most of the issues that you (Smith) observed were associated with morphology and non-motility. So those cells are moving well, but they look different,” Fontes says.

Performance and ADG

When evaluating performance or average daily gain (ADG), Smith reports there was no change between bull groups.

“There actually were no differences between our categories of top, middle and bottom bulls, our top bulls were not gaining any more than our middle and bottom bulls were, so they were all kind of following the same trend,” Smith reports.

Fontes interprets this finding as significant, suggesting that “it’s not a matter of allowing those bulls to express their genetic potential for growth” but rather about understanding fat deposition.

Smith agrees, saying, “It’s about essentially where that fat deposition occurs, and that’s how it matters.”

While producers might worry about restricting bull growth, the research suggests that careful monitoring of fat distribution is more important than preventing weight gain.

Fontes summarizes the key takeaway from the research is the ability of bulls to pass a BSE appears more related to body condition score and over-conditioning rather than their overall growth potential. Excessive back fat can negatively impact a bull’s reproductive potential, even if it doesn’t affect its growth performance.

Your Next Read: Wanted: Bulls Ready to Work

Strategies to Improve Pregnancy Rates in Cow Herds

Thu, 28 Aug 2025 14:32:25 GMT

For many producers and veterinarians, it’s time to line up PG and ultrasound appointments to establish a pregnancy rate and sort off open cows. It can be a nerve-wracking day until it’s over — and even then ranchers may not be entirely satisfied with the outcome.

So, what can ranchers do if they aren’t satisfied with their herd’s pregnancy rates?

It’s beneficial to look at both an industry average and a herd average in these instances.

“If you have a 60 to 80 day breeding season and are over 90% for pregnancy rate, you are doing pretty well, according to previous North Dakota surveys,” says Lacey Quail, North Dakota State University extension livestock management specialist. “If you have a shorter breeding season, you can expect that percentage to be a little lower.”

Next, take a look at your herd records from previous years.

“If you get your PG or ultrasound results and aren’t happy, it implies you have previous records to compare it to,” Quail says. “We need to keep herd records so we can dig out something that might go under the radar and potentially cause profit loss.”

Fertility is multifactorial, which can sometimes make it challenging to pinpoint one specific cause.

She recommends producers start by asking themselves a series of questions to start narrowing down what may have caused lower pregnancy rates and where the problem occurred.

Several management questions producers can ask themselves to start to tease out the potential cause of lower pregnancy rates are:

Did you see cows cycling?
Did you see bulls mounting and breeding?
Did you see breeding activity at the beginning or end of the season?
Were the majority of open cows in one pasture or management group?
Are some of the open cows thinner than the rest of the group?
Were the majority of open cows of a certain age?
Did you experience a heat spell or other potential stressor?

Quail says, “Fertility is like a domino train. You are waiting for the last domino to fall, but the train may have fallen off track a long time ago in a different room.”

Once you answer the above questions, be mindful of the following missed opportunities.

“On the bull side, make sure you are having full breeding soundness exams completed by a veterinarian and take into account social hierarchy when putting together breeding groups,” Quail says.

After that, it’s important to remember breeding activity.

“A big missed opportunity is not taking the time to observe breeding behavior in your herd,” Quail says. “We want to evaluate if cows are cycling, and if bulls have the libido to seek, mount and breed. Noticing issues early can save a great deal of loss.”

Don’t just stop at noting activity in general. When did the activity happen?

“Take a closer look at when cows are getting pregnant, and not just if they are getting pregnant,” Quail says. “This can have a big impact on overall productivity and profitability.”

Nutrition also can’t be overlooked.

She says, “In many cases, cows calving early might reach peak lactation and breeding season before growing forages can support all their nutrient requirements. Keeping females in adequate body condition going into and out of the breeding season is going to go a long way toward overall pregnancy rate.”

Environmental stressors can’t entirely be avoided, but they can be mitigated.

“Another missed opportunity is fine tuning environments to reduce stress,” Quail says. “We can’t control the heat, but we can control to some degree how far cows and bulls have to walk to access water.”

Ranchers shouldn’t feel like they have to go through this process alone. They can reach out to specialists, veterinarians and their nutritionists for help.

“Consulting with a veterinarian regardless of your pregnancy rate is a good thing to do,” Quail says. “Some records to be aware of and share with your vet are differences in pregnancy rate and calving rate as well as any co-mingling with neighboring cattle.”

May your pregnancy rates be favorable this fall. But if not, remember to start with herd records and basic questions to help get to the cause.

You can listen to the full conversation on the Casual Cattle Conversations podcast .

Is It Time to Pull Bulls?

Mon, 14 Jul 2025 21:01:05 GMT

The old rule of subtracting three months and adding seven days to the current date on the calendar is good to remember when deciding if it’s time to pull herd bulls from breeding pastures.

If we pulled bulls on July 14, we could expect calving to potentially last until April 21. Short breeding seasons equate to short calving seasons. Short calving seasons offer the benefit of a more uniform and accordingly more valuable calf crop at weaning.

Short breeding seasons are the goal; however, most breeding seasons fall into a range of 45 to 90 days. There are several factors to consider when making this management decision.

Bull management and proper care can be accomplished more effectively after bulls are removed from cows. Younger bulls that are still growing will benefit by going back into a dry lot management scenario where it is easier to provide supplemental feed and gain back body condition lost during breeding season. This is the equivalent of re-charging a battery to get them on track for the next breeding season. If using multiple bulls in a pasture, it is logical to leave an older bull (or bulls) on the job while pulling out the younger bulls.
When is the date of your latest calf born? Typically, cows need 60 to 75 days post-partum to be prepared to breed back. Two-year-old cows nursing their first calf are typically the greatest rebreeding challenge.
Pregnancy checking can be done sooner when bulls are pulled earlier. Identifying and culling open cows in a timely fashion saves forage and capitalizes on cull cow value now as opposed to lower values moving later into fall.
What is your plan for open cows at pregnancy check? Cull open cows are at record high prices. That being said, a bred cow has more value than an open cow. Do you have a fall calving herd to roll opens into?
If a high percentage of cows return to heat after 40 days of breeding, have bulls rechecked for fertility and cows and bulls examined for reproductive diseases by your veterinarian. Change bulls, if necessary, and re-evaluate the previous year’s nutrition program.

Open Heifers Explained: What You Need to Consider to Increase Preg Rates

Mon, 30 Jun 2025 21:09:29 GMT

A producer has a group of 112 heifers. The heifers were synchronized, and after a 45-day breeding season only 80% were confirmed pregnant.

During a recent “ Bovine Science with BCI ” podcast, Kansas State University veterinarians Brad White and Bob Larson explore potential causes for the issue — from bull problems to nutritional and health-related factors. They also share practical strategies and management tips producers can implement to improve reproductive success and set the herd up for a better breeding season.

Larson says, while the pregnancy rates weren’t optimal, the results weren’t catastrophic. The first breeding cycle performed well.

Reviewing the pregnancy data they determined:

57% of heifers became pregnant in the first 21-day breeding cycle.
After synchronization the heifers were artificially inseminated and then turned out with bulls. Larson says the goal or expectation should be 60% to 65% every 21 days so 57% is not too low.
39% of remaining heifers got pregnant in the second 21-day cycle.
Larson explains this is the rate that is the biggest problem and concern.
The final breeding period (about four days) added a few more pregnancies.

White explains about those who conceived in the first cycle, “Those heifers kept out of this scenario are going to be great cows for the herd. They’re bred at the right time.”

According to the veterinarians the potential reasons for the less-than-ideal pregnancy rates after the first cycle include:

Heifer Factors
Heifers were initially developed in a dry lot with a high body condition score (7 out of 9) then moved from dry lot to native range after initial breeding. Larson says the potential body condition loss could have impacted fertility as a negative energy pattern can pause a female’s estrus cycle.
Bull Factors
The producer turned out the 112 heifers with five bulls — three yearlings and two mature bulls. With the conception after the first cycle, the bulls had approximately 48 heifers to service. Larson explains the biggest concern is the synchronization created a concentrated breeding period and the bulls might have struggled with multiple heifers in heat simultaneously. Another fertility consideration is social dynamics and breeding behavior.
“The only solution I have for that is more bull power,” Larson says. “And that can get expensive, really fast, when you think about dollars per pregnancy during that second 21 days, when you know 60% of them are already pregnant.”

After reviewing the case, Larson gave these recommendations to the producer:

Target and maintain heifer body condition score around 6 (not 7)
Avoid significant body condition changes during early pregnancy
Carefully time movement from dry lot to pasture
Consider smaller heifer groups
Potentially rotate bulls between groups
Explore heat detection and re-breeding options
Evaluate bull power and allocation strategies

The discussion highlights the complexity of heifer breeding, emphasizing that multiple factors can influence pregnancy rates. Larson summarizes careful observation, strategic management and understanding the biological and social dynamics of the herd are crucial to improve reproductive success.

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Early Shedding Cows Produce Heavier Calves at Weaning

Thu, 22 May 2025 14:08:04 GMT

Early summer hair shedding is a proven trait of economic relevance for producers in areas of increased heat and humidity and those grazing endophyte-infected (hot) fescue. University of Missouri research indicates hair shedding is important to more than just Southern cattle producers.

“Animals who shed their winter hair coat sooner are less likely to be exposed to heat stress in the summer,” says Jamie Courter, University of Missouri beef genetics extensions specialist. “These animals are also more likely to wean heavier calves and remain productive in a herd, for longer.”

Figure 1 shows the average weaning weight of calves born to dams who began shedding their winter coats between March and July. The average weight of a calf born to a dam that shed in March was 57.2 lb. heavier than those that shed in July.

Figure 1 shows the average weaning weight of calves born to dams who began shedding their winter coats between March and July.

(University of Missouri)

Research at the University of Missouri has found a relationship between hair shedding scores and length of daylight. Thus, hair shedding may serve as an indication of an animal’s ability to sense and respond to their environment.

Courter says the relationship makes hair shedding useful for producers outside the Southern U.S.

Hair-shedding Scores

Hair-shedding scores represent a visual appraisal of the extent an animal has shed their winter coat. Reported on a scale of 1 to 5, the lower the assigned score, the more hair an animal has shed. Half scores, such as 3.5, are not reported.

Hair shedding scoring system.

(. Adapted from Durbin et al., 2020. Genetics Selection Evolution 52:63)

Cattle tend to shed hair from the front to the back and from their topline to their belly (Figure 3), but there is individual animal variation in this pattern. Typically, animals begin shedding around their neck, followed by their topline. The last spots to shed are an animal’s lower quarter above its hock and its underline.

Figure 3. Diagram of typical hair shedding regions in cattle aligned to their hair shedding score. Cattle shed from head to tail, top to bottom, with some variation. Numbers represent areas where hair would be expected to shed for a given score.

(University of Missouri)

Courter says the time to evaluate cattle for hair shedding will vary by geographical location and environmental conditions. Animals should be scored when the most variation exists within the herd.

“There should be a few animals who receive a score of 1, a few who score a 5 and a majority receiving a hair shedding score of 3,” she explains.

Cattle begin shedding their winter coat in late spring through the summer. For many locations, mid-May has been identified as an ideal hair-shedding evaluation period. The hotter and more humid the climate, the earlier in the spring scores should be collected.

Hair shedding is a moderately heritable trait (h2=0.35 to 0.42). This means that incorporating a hair-shedding score into culling and replacement heifer selection decisions will result in genetic change over time.

“Although hair shedding has traditionally been associated with heat stress and fescue toxicosis, recent research shows this quick and easy phenotypic assessment of cattle could be a trait of even more economic importance,” Courter says. “With its moderate heritability, combining this score with a hair shedding EPD or score on bulls would result in positive genetic progress over time.”

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Cow Herd Scorecard: Evaluating Performance Post Calving

Wed, 14 May 2025 21:59:31 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.

For spring-calving herds, now is the time to evaluate and review calving success and failures.

“This is a good time of year to review your records, and if the numbers aren’t where you want them to be, you can make management adjustments under the guidance of your veterinarian, nutritionist or another adviser,” says Jason Warner, Kansas State University cow-calf Extension specialist. Warner was a guest during a recent K-State Beef Cattle Institute Podcast .

A herd’s postcalving scorecard should include:

pregnancy percentages
death loss
calving ease/calving complications – prolapse or retained placenta
udder scores
body condition score
mothering ability and disposition
calving interval

Two areas Warner tells producers to focus on are the number of live calves born compared to the number of cows exposed to bulls at the start of the breeding season; and the number of cows that became pregnant early in the breeding season.

A top priority for Bob Larson, K-State veterinarian, is to have calves born early in the calving season.

“The goal is to have 65% of the calves born in the first 21 days, and 85% to 90% of the calves born within the first 42 days of the season,” Larson say. “If that happens, I know that the cows were in good body condition at the start of the breeding season and the bulls were fertile.”

Larson references USDA’s National Animal Health Monitoring Service (NAHMS) for national averages on abortion and calf death loss.

“The national average is between 1% to 2% for calf death loss and that will vary from year to year within the same operation,” Larson said. “If the producer is calving out a high percentage of heifers, that can influence the calf death loss percentage.”

Scorecard Prep
Ron Lemenager, Purdue professor and beef Extension specialist, suggests producers consider creating a spreadsheet to calculate important percentages, prior to filling out their postcalving scorecard.

He encourages producers record and monitor these numbers each calving season:

Number of cows exposed
Number of cows pregnant
Number of cows pregnant / Number of cows exposed = % Pregnant
Number of pregnant cows kept to calve
Number of cows that calved
Number of cows that calved / Number of pregnant cows kept to calve = % Calving
Number of Live Calves
Number of Live Calves /Number of cows that calved = % live calves born
Number of live calves after one month
Number of difficult or assisted birth (dystocia, prolapse)
Number of cows with bad udders
Number of cows BCS 5 or 6
Number of cows with poor disposition and poor mothering ability
Number of cows that calved in the first 21 days
Number of cows that calved in the second 21 days
Number of cows that calved in the third 21 days
Number of cows that calved after 63 days

Lemenager explains using the spreadsheet to calculate the percentages can help producers identify specific problem areas in their calving and breeding processes and allows them to troubleshoot their herd’s breeding performance.

“Tracking herd performance allows producers to zero in on their problems and determine what issues are really facing the herd,” he summarizes.

Understanding the challenges facing a cow herd can help producers determine what nutrition or management strategies can be used to improve their herd’s postcalving scorecard in future years.

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Can We Get Calving Ease Without Sacrificing Performance?

Thu, 01 May 2025 15:53:27 GMT

Sire selection for natural service or artificial insemination (AI) is critical. Over time, 90% of genetic change is the result of sire selection. Your bull (or bulls) contribute more to the genetic makeup of your herd in a calving season than a cow does in her lifetime.

Effective sire selection should be based on genetic values in the form of EPDs or expected progeny differences . Selection on EPDs is 7 to 9 times more effective than selection based on individual performance data, within herd ratios or performance testing because all this information (plus more) is taken into consideration in calculating EPDs.

Selecting genetically superior sires is the fastest approach to herd improvement and bottom-line profitability when you select genetic superiority that matches your management, production and marketing system.

If you are identifying bulls to breed heifers this spring and calving ease is a priority, current sexing technology can work to your advantage. Research shows that heifer calves are, on average, approximately 5 lb. lighter than bull calves at birth. The lighter birth weights will equate to less likelihood of dystocia.

If sexed heifer semen is your preferred path to calving ease, expect to pay a little more (approximately $20/straw) per unit than typical of conventional semen. As well, timing of AI should also be delayed by six to 12 hours if using sexed semen.

Charting the genetic trend of beef breeds indicates purebred cattle breeders have been very successful over the past 30 years of applying selection pressure to maintain calving ease while improving the additive genetic merit for weaning and yearling weight performance. What we commonly refer to as “curve benders” are easier to find than ever, especially when sorting through bull stud offerings of potential AI sires.

So to answer the questions in the title, yes it is possible. With ample calving ease sires available in the current marketplace, you should still be able to identify sires that give you the growth, carcass merit or levels of maternal performance you seek to improve your operation’s bottomline.

Mark Johnson, Oklahoma State University Extension beef cattle breeding specialist, discusses the changes occurring in the cattle industry.

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Mild Winter for Calving Helps Protect Valuable Asset

Sat, 26 Apr 2025 16:49:03 GMT

The nation’s cattle herd is at a 73-year low due in large part to the historic drought that hit prime cattle production areas. However, Mother Nature was fairly kind during the calving season this year, at least in states such as Iowa.

“In general I think this was one of the nicest calving seasons we’ve had for a while,” says Dr. Brett Terhaar, a technical service veterinarian for Elanco Animal Health, in Winterset, Iowa.

Healthy and productive calves are a huge asset for producers, especially with historically high prices. One lost calf can translate into a financial hit for a cattle operation.

“I have seen minimal problems with scours and pneumonia. I think this set of calves moving to grass is as good as I’ve seen when I look back over the last 10 years,” Terhaar explains.

Management is still the key to disease prevention and ensuring calf performance, he says, but a comprehensive vaccination program provides a good return on investment.

“I can’t make a vaccine that can overcome poor management. So that’s No. 1, animal husbandry. But vaccines are important,” Terhaar adds. “I don’t want to over-vaccinate, but we want to do the basics, and make sure those are done in a timely fashion.”

A mild winter has also been beneficial for cow health and body condition.

He says cow culling has slowed in areas not facing lingering drought but herd rebuilding and heifer retention is also slow.

“Are we seeing heifer retention? I don’t know that it’s much above just maintenance,” Terhaar says. “I think people are enjoying these big prices, so they’re taking the cash for heifers and taking it to the bank, which is probably smart. But at some point, we have got to keep some heifers and make some cows.”

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Enhancing Meat Quality Through Management Decisions Pre-Calving

Tue, 08 Apr 2025 18:41:17 GMT

Meat quality is influenced by various factors that affect the consumer’s eating experience, including tenderness, marbling, and fat composition . While many factors contribute to the final product, beef producers play a key role in shaping meat quality through their management and nutritional decisions, even before an animal is born.

Production systems vary widely based on climate and economics, but management choices made before birth can significantly impact meat quality. Key decisions include breed selection and maternal nutrition .

Breed type affects meat quality. Bos taurus breeds, such as Angus and Hereford, tend to have higher marbling scores than Bos indicus breeds. Crossbreeding beef and dairy genetics can optimize efficiency and carcass quality, with research ongoing to determine the best breed combinations for superior meat characteristics.

A dam’s uterine capacity and diet during pregnancy directly impact the offspring’s muscle development, fat composition, and overall meat quality. Intrauterine growth restriction can limit muscle fiber development and reduce marbling. Proper maternal nutrition helps mitigate these effects. Studies show that protein supplementation during gestation improves marbling and meat tenderness, while both undernutrition and overnutrition of the beef cow during gestation can negatively impact carcass traits of their calves.

Feeding antioxidant-rich diets to pregnant cattle can enhance the offspring’s meat quality by improving shelf life and flavor stability. Research suggests that plant-based antioxidants, such as rosemary and thyme, can reduce fat oxidation, preserving meat tenderness and taste.

Beef producers have a significant influence on meat quality through breeding choices and nutrition management. Understanding these factors and implementing best practices from conception through finishing can lead to higher-quality beef, improving both consumer satisfaction and market value.

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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.”

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Calving Tips: Dealing with Protective Moms

Tue, 08 Apr 2025 13:24:28 GMT

As spring calving season continues, producers continue to monitor and assist when needed as their next calf crop hits the ground. Dealing with protective moms can be a challenging situation, two industry leaders and a producer share their tips on how to prevent and cope with the situation when faced with an unruly cow.

The first 24 hours is a key time in the newborn’s life. Ron Lemenager, Purdue beef specialist, says calves older than 24 hours are typically hard to catch, so if you plan to process the newborn, it should be done as soon as possible after birth.

“Outside of colostrum, I don’t often talk about some of the other chores that might need done in that time period,” says AJ Tarpoff, Kansas State University Extension veterinarian. “Simply because it’s different for every operation.”

Work as a team: It’s hard to know if you are in danger without someone watching your back. One person can entertain the cow, while the other can tag or accomplish what is needed.”

(Angie Stump Denton)

Depending on your management program, producers may choose to perform some of these tasks in the first 24 hours: tagging, castrating, dehorning, taking birth weights, giving selenium injections or recording calf information in a calving book.

It might be necessary to use nutritional supplements/injectables depending on the operation and cow status. Tarpoff encourages producers to discuss proper products and protocols to use at calving with your veterinarian prior to the first calf hitting the ground.

Commercial cattle producer Tyler Tobald, JTAC Farms, Glasco, Kan., shares his process for newborn calves.

“In the first 24 hours after calving, I will usually put ear tags into the calf,” he says. “If the calf is a bull, I band it. Then, I give the calf some oral vitamin A, D, E, B12 gel while I use a leg band to get its weight. We rotate our calving areas in different parts of the pasture and attached field. After I’m all done tagging, I enter the calf into CattleMax and record any other notes about the cow and calf that I deem important to know for the future.”

Obviously, cow behavior can be a factor when processing a newborn. Just like the video published with this story, sometimes a protective mom decides she is not happy with a producer touching her calf. Tobald says his goal is to keep a cow’s stress levels down as much as possible.

“I check the pair out on a side-by-side,” he explains. “When I roll up, I try to be as quiet as possible and not just zoom up on them. After that, I try to be as quiet as I can. I don’t hoop, holler, talk or anything that will add stimulation to an already stressful situation. I also always keep the cow in front of me as best as possible. The last thing I want is for an amped up 1,300-lb. animal behind me where it can sneak attack me.”

Tobald says his philosophy on dealing with cows, even the over-protective ones, is using the most important of the Roadhouse Rules: Be nice until it’s time to not be nice.

“Thankfully this is a very rare occurrence,” he says. “I make notes of any cow that is over-protective, so I know what I’m dealing with when I approach them in the future. But if the cow gets more aggressive the next year, then the calf doesn’t even get tags and gets loaded into a trailer with the cow and they go to the sale. Life is too short for crazy or mean cows.”

Lemenager explains that right after a cow gives birth, her hormones are raging.

“That’s part of the process that helps her bond to that calf,” he says. “She also needs to stimulate the calf, so it gets up and nurses. If any part of that natural process is interrupted, the cow can become very aggressive.”

Tarpoff shares these tips for dealing with overly protective mother cows.

Have some type of physical separation from mom. This might be a fence, panel, gate, truck, side-by-side. “The only truly safe location is to have a physical barrier between you and the cow while working with the calf”
Work as a team. “It’s hard to know if you are in danger without someone watching your back. One person can entertain the cow, while the other can tag or accomplish what is needed.”
Be efficient and thoughtful with the calf manipulation. “It only takes one painful bellow from the calf to set the cow off. Save potentially painful manipulations until last (ear tags or castration).
Be smart. “Don’t assume cows are faking a threat. When in doubt, always take the safe approach. The chore can always be completed later if the cow is on the fight. Keep records and plan to handle the situation when she calms down.”
Stay safe. “If we get injured, we put stress on the rest of our family and operation.”

Different strategies can help keep the producer and calf safe during newborn processing.

“Some ranchers use a cage on the side of their ATV,” Lemenager explains. “This allows for bringing that calf into the cage while handling it. Another option is to have two people working with the calf. One to care for the calf and the second to keep the cow away.”

If you are going to try to move a calf to another location, an option is a polypropylene plastic sled or a calf carrier on an ATV (calf sling). Lemenager says a cow will typically follow because she can smell and see her calf.

“Ideally, when working with a cow-calf pair, I try to keep the calf between me and the cow,” Lemenager says. “Most, but not all cows, are calmer and less aggressive when they can see and smell their calf.”

Lemenager summarizes a key to improving your cow herd behavior is to consistently use low-stress handling to help desensitize cattle to the presence of people.

Follow Tobald or JTAC Farms on Facebook or TikTok for more examples of low-stress handling and cow management.

Your Next Read: Calving Signs in Cows and Heifers

Gene Editing: Livestock Genetic Improvement Through DNA Editing

Mon, 17 Mar 2025 17:18:10 GMT

Traditional cattle breeding has always involved modifying the genetics of animals, but the term “genetic modification” is often associated with more modern biotechnologies like genetic engineering and gene editing.

“Often when people hear the expression ‘genetic modification’ what comes to mind is the whole GMO debate and scary memes on the Internet, or that if you eat GMOs something bad will happen to you,” says Alison Van Eenennaam, UC Davis animal biotechnology and genomics extension specialist. “That narrative has been very hard to correct.”

Van Eenennaam was a featured speaker during Kansas State University’s Cattlemen’s Day on March 7. Genetic engineering, which has been around for about 30 years, involves introducing transgenic constructs from other organisms, such as Bt corn. However, this technology has seen limited use in animal production due to consumer pushback against GMOs and the difficulty of introducing new traits into animals, Van Eenennaam says.

A newer technology called genome editing or gene editing has emerged in the last decade.

“Gene editing is basically just conventional breeding, but done more intelligently,” she summarizes. “This allows for the targeted manipulation of an animal’s DNA without introducing foreign genetic material. For example, researchers have developed a ‘PRRS-resistant’ pig by knocking out a gene that the virus uses to infect the animal. Gene editing can also be used to introduce beneficial alleles from one breed into the elite germplasm of another, without diluting the desired genetics.”

In cattle, gene editing has been used to create knockouts for traits like disease resistance and heat tolerance, as well as knock-ins to introduce desirable alleles like the polled trait.

“In 2009, we were able to define the entire sequence of the cattle genome, which gave us a look at the genetic variation that exists between cattle breeds,” Van Eenennaam says. “In the case of cattle, that’s about 3 billion base pairs of DNA that make up the cattle genome.”

She explained there are two ways to gene edit cattle — cloning and microinjection into zygotes. “The key difference is that cloning starts with an edited cell line, while microinjection edits the zygote directly,” she says. “Ultimately, the goal is to produce a homozygous, non-mosaic animal where both alleles carry the desired edit, ensuring the trait is passed on to offspring.”

Van Eenennaam explains a few of the cattle-focused gene editing projects have centered around traits like polled, disease resistance, heat tolerance and muscle development.

In the swine industry, she says gene editing is being used to improve a pig’s resistance to Porcine Reproductive and Respiratory Syndrome (PRSV), a devastating disease that costs the swine industry about $1.2 billion per year in the U.S.

A gene editing project that could have a big impact the beef industry is surrogate sires or “artificial insemination on legs.” The process produces bulls that are generating semen from a different cell line. For example, a tropically adapted bull working in an environment where he is well suited, but his semen could be genetically, an Angus sire.

“You can basically do AI on legs, because you could naturally service with elite germplasm,” she says. “There’s a lot of different applications that have some potential to really benefit the beef industry.”

Gene editing technology still faces regulatory hurdles in the U.S., as well as the need to overcome perceptions among countries that buy U.S. beef.

Van Eenennaam says the main risks with gene editing are more reputational than safety-related, as activist groups may try to lump gene editing with GMOs. She encourages more discussion highlighting how gene editing can address issues like animal welfare and disease resistance in ways that align with consumer values.

Excited about the potential of gene editing to improve livestock production in a targeted and precise manner, she summarizes that regulatory approaches will be crucial in determining which applications reach the market and who can bring them forward.

You can watch her K-State Cattlemen’s Day presentation here: https://youtu.be/d7N7a6mYwDk

Your Next Read: Modern and Precise: Using Gene Editing to Change the Blueprint of an Organism

Uncover the Economic Power of Bulls

Tue, 18 Mar 2025 13:21:51 GMT

When cattle producers consider making bull purchases for their cow-calf operation, those bulls need to be evaluated relative to the benefits each offers the bottomline, according to Mark Z. Johnson, Oklahoma State University Extension Beef Cattle Breeding Specialist. Johnson says producers need to find the value proposition of those bulls.

Value proposition is defined as how a product or service can meet a customer’s needs and help them achieve their goals.

He shares these key points for producers to remember.

The initial cost of the bull is only one part of the profit equation. Value added to calves is equally important.
Identifying the trait (or traits) of primary economic importance is critical to determining the value proposition of each bull.
Producers need to have a budget and it needs to be realistic.
When multiple traits have economic importance, determining the value proposition of a bull is more challenging. It will require looking at current levels of production in traits of importance in order to determine where to focus selection pressure.

Put pencil to paper
Johnson gives the example for a cow-calf producer who needs two more Angus bulls for the spring and has narrowed down the selection list to the following five bulls to purchase private treaty.

ID	CED	BW	WW	YW	CEM	HP	MW	Marb	$B	Price
1	12	0.2	70	120	9	13	76	0.35	154	$10,000
2	4	2.9	82	141	12	6	96	0.79	180	$8,000
3	15	0.1	78	145	14	17	86	1.80	215	$12,500
4	5	3.5	91	157	8	5	99	0.71	185	$7,500
5	11	0.7	63	108	8	10	65	1.90	189	$5,500

The bulls are all spring yearlings and will be approximately 15 months of age at turnout and accordingly should be expected to cover 15 cows this year. All the bulls have passed a Breeding Soundness Exam and sell with a registration paper and a breeding soundness guarantee.

“The buying decision boils down to identifying the right bulls for your operation,” Johnson says. “The right bulls to buy are the ones most capable of adding value to the calf crop sired relative to their purchase price.”

The bulls selected need to:

Complement the females to which they will be mated
Offer genetic values of economic relevance to the marketing endpoint of the calves they will sire.

As an example, your operation intends to use the bulls as terminal sires on spring calving cows, four to six years of age. After weaning, the calves will run on cool season grass until marketed as yearlings. In this operation the trait of primary economic importance is Yearling Weight (YW).

What bulls would you buy and why?
Johnson says to calculate the profit potential of each bull, assume each bull will sire 125 calves over their lifetime of service. Each will have the same salvage value and the value of a pounds of YW sired will be $2.50.

Table 1. Use the least expensive bull as the baseline to compare.

(Mark Z. Johnson/Lori Hays)

Table 2. The “Value Proposition” of each bull over their lifetime of service.

(Mark Z. Johnson/Lori Hays)

Read more: Answer These Cow Herd Questions to Help Make Smart Bull Selections

Three Questions to Ask Yourself When Preparing to Purchase Bulls

What is a Good Bull Worth in 2025?

Wed, 05 Feb 2025 17:13:51 GMT

The spring bull buying season is here, so it’s time to revisit the age old question. The question has been asked forever, or at least as long as we have been breeding cattle with a notion of trying to make the next generation better. It is a classic and timeless question. It is an important question. At this time of year, when many bulls are being marketed and we are planning ahead for spring breeding season, it is a question that is asked a lot!

The Answer

I remember first hearing the answer nearly 40 years ago as a student at OSU.

“A good bull is worth the value of five calves he sires.”

I’ve heard that answer again many times over the years. It is a good answer and a good rule of thumb to follow, the problem is it doesn’t exactly narrow down the range. If we do a little “cowboy math,” this answer may in fact lead to more questions.

What is considered a “Good Bull”?

For this discussion, qualifications to meet “Good Bull” status are:

A bull that sells with a registration paper, which includes pedigree information and a complete set of genetic values (including EPDs and Bio-economic indices) to be considered in the selection process.
A bull that has passed a Breeding Soundness Exam (BSE) and selling with a breeding soundness warranty (terms will vary).

When are we marketing our calves? What is their value?

According to the most recent (Jan. 21, 2025) Oklahoma Market Report:

524 lb. weaned steer calves (Large, 1) are worth about $3.50/lb. for a value of approximately $1,834 per head. Therefore, if my future marketing plan is to sell weaned steers, $1,834 x 5 = $9,170 is the answer.
912 lb. yearling steers (Large, 1) are worth about $2.53/lb. for a value of over $2,300 per head. Therefore, if my future marketing plan is to sell yearling steers, $2,300 x 5 = $11,500 is the answer.
1,500 lb. finished beef steers are worth $2.00/lb. live for a value of $3,000 each. Therefore, if my future marketing plan is to retain ownership through finishing and sell fed cattle on a live weight basis, $3,000 x 5 = $15,000 is the answer.

So, in the current market, a good bull is worth somewhere between $9,000 - $15,000 to a commercial cow-calf operation. Where exactly in that range depends on your marketing plan and the market conditions at that time. Not an exact number because there are many variables in play.

One key point illustrated here is that the longer you own the offspring before marketing, the greater the value of the bull to your operation. Retained ownership gives you more time and opportunity to capture the value of your investment in genetics. It is noteworthy that we haven’t considered the value added to replacement females a bull will sire. Bulls used to sire the next generation of cows have an even greater long-term economic impact on the profit potential of your operation and should be valued accordingly.

I encourage cow-calf operations to consider their production system and marketing plan. Doing so should dictate where to apply selection pressure. Genetic values pay when you purchase bulls capable of improving genetic potential for the specific traits that will translate to added value at your intended marketing endpoint.

Keep the following chart in mind as another way to evaluate ownership cost of bulls on a per calf sired basis.

(Johnson/OSU)

Your next read: Weathering Winter Challenges: Tips for Feedlot Success

7 Ways to Help Beef Producers Evaluate Potential Replacement Heifers

Mon, 02 Dec 2024 19:16:35 GMT

Given the price of replacement beef heifers today, one of the questions veterinarians are helping cow-calf producers address is whether it’s a better decision to raise their own calves for replacements or buy them.

The answer, like with many complex decisions, isn’t a simple yes or no, according to Dr. Ray Stegeman.

The Missouri veterinarian says he has cow-calf producers who do raise their own replacements, but it’s not a practice he recommends for everyone.

“I work with quite a few smaller family farmers who keep heifers and are successful with that. But they know the mama cows and everything about them going back 50 years, which has merit,” says Stegeman, who owns Osage Veterinary Clinic in St. Thomas, Mo., and is a member of the Production Animal Consultation (PAC) network. “But if a producer is just starting out, it’s often advisable to buy bred heifers, given the economics of developing a heifer and the time involved.”

Stegeman, referencing research at Texas A&M and University of Nebraska, says a 200-cow herd size is often a practical starting point for deciding whether buying or raising replacement heifers is the better option.¹

Size Of Calf Crop And Resources

There are several reasons why a 200-head cowherd is a good minimum threshold. For one thing, there’s a large enough calf crop born to provide an adequate number of high-quality prospects for the farm. Three other considerations: this size of operation often has adequate manpower, physical facilities and land necessary to make the undertaking feasible and worthwhile.

“I think we tend to overlook or not realize the costs and resources that go into developing a replacement heifer,” Stegeman explains. “For example, you need to have enough pasture available, you have to keep a bull away from these heifers and raise them separate from the cowherd, and that takes additional resources.”

Here are seven additional factors Stegeman, other veterinarians and beef Extension specialists take into consideration as they work with cow/calf producers who are raising their own replacement heifers.

1. Monitor calves early. Stegeman advises his producers to start looking at their prospects during preweaning, managing nutrition proactively to prevent underfeeding or overfeeding.

“Everyone wants to pick a good-looking heifer, but you don’t want the heifer still on the mother cow to get too fat,” he says. “If we’re creep feeding, we want to watch our starch. If that heifer is too fat at weaning that in and of itself can be a setback.”

Heifer calves that are too fat have been shown to have reduced milking ability once mature, according to Oklahoma State University Extension research. Mammary development is in a critical stage from 2 months of age until about 9 months, or just before puberty.²If a calf is storing considerable amounts of extra fat during that time, excessive fat can be deposited in the mammary gland and inhibit its development.

Stegeman adds if the calf has too much body fat that has the potential to cover up physical defects, which might only be discovered after the producer decides to retain the calf.

In addition, Stegeman likes to talk with producers about nutrition and environmental factors the dam experienced while carrying the calf. He considers whether the mother cows were subjected to drought conditions or inadequate nutrition or other environmental factors.

“Fetal programming factors can result in potential negative productivity in the heifer calf following it through to maturity,” he tells Bovine Veterinarian.

2. Heifer calves born earliest are usually the top picks. Older heifers are more likely to reach the desired target weights by the start of breeding. Early puberty is moderately to highly heritable and positively related to future reproductive efficiency.

“Fertility is driven by genetics, so much so that it’s very important to pick those heifers born early in the calving season as replacements” Stegeman says.

During the selection process, producers with their veterinarian’s help, should look for heifers that are structurally sound, have a wider structural frame and a body type of more rib shape and depth, recommends Mark Z. Johnson, Oklahoma State University Extension beef cattle breeding specialist.³

Johnson adds that fleshing ease equates to breeding females that can better maintain body condition and energy reserves on a given amount of feed.

3. Consider genetic merit. Genetics are an important consideration, as producers plan the type of heifers they want to raise and keep and the traits needed to meet their goals.

“I think one of the problems with the beef industry today is that we’re choosing heifers from the steer pool of genetics – we’re choosing heifers out of carcass genetics,” he says. “There’s opportunity in the beef industry to have maternal herds producing genetically superior replacement females for cow/calf operations to purchase, which will be important going forward.”

4. Put prospective replacements on pasture, once they’re weaned. “We like to develop heifers on the pasture that they’re going to see as an adult cow,” Stegeman says. “They essentially program themselves, and after they calve the first time, they’ll perform better and stay in the herd. Don’t push them too hard with grain,” he cautions. “Go for the pound and a half to 2 pounds of gain per day.”

5. Don’t overlook the importance of temperament. A heifer can look like a great fit for the farm but still be an animal the producer needs to cull, because of her attitude and behavior.

Mississippi State Extension beef specialists encourage producers and their veterinarians to use a chute scoring method to keep temperament records.⁴ When heifers are restrained in the working chute, they can be assigned a score from 1 to 4 (1 = calm; 2 = restless shifting; 3 = squirming; 4 = twisting and rearing). Temperament is a very heritable trait, and removing temperamental heifers from the herd improves safety for farm employees as well as other members of the cowherd.

6. Protocols are needed for heifer vaccinations and deworming. For replacement heifers, Stegeman recommends administering a modified live viral vaccination and an initial leptospirosis vaccine at weaning time, when the animal is 6 to 7 months old.

“We’ll then deworm, often with a combination product, at that time as well,” he says.

Once heifers reach the 12-month mark, they are then administered a second round of vaccinations and dewormer.

“With some of the longer synchronization protocols now, we can give them their last pre-breeding vaccination the day we set them up, as it is approximately 33 days to breed from day one to AI or bull turn out,” Stegeman says. “Often, to save on number of trips through the chute, we try to consolidate processing.”

7. A pre-breeding examination is good insurance. Stegeman recommends that veterinarians reproductive tract score the heifers, either via ultrasound or manual palpation, at around 45 days prior to breeding. He says to measure the pelvis to make sure it is at least 150 square centimeters in size.

“We don’t want to set that number too high. We don’t want to say, ‘Well, my heifers need to be at 180 square centimeters,’ because then we’re just selecting for a big cow,” says Stegeman, citing research by David Patterson, PhD, emeritus beef Extension specialist at the University of Missouri.

With tract scores, Stegeman looks for scores of four and five, which indicate the heifer is ready to breed.

“We can start them on synchronization for breeding,” he says. “If needed, with some of the twos and threes, we’ll put them on feed to hopefully increase their tract score. Research indicates it takes at least 20 days to increase the tract score. If we have enough of the lower scoring heifers, and we deem it necessary, we can sort them out from the fours and fives to bump up their tract score using increased feed,” Stegeman adds.

He notes that the reproductive tract score along with the pelvic measurement provides the producer with some insurance that he is hanging on to the ‘right’ versus the ‘wrong’ heifers.

“The veterinarian can save producers money and time with these practices,” Stegeman says. “If you wait until preg check time to cull those heifers that’s not a good decision for the producer, because he’s got all the extra expense and feed into them up until that time. You might as well put them in the feedlot or develop them out for feeding earlier in the process,” he says.

¹DocTalk, Thomson, Dan. DocTalk Ep 462 - Heifer Development with Dr. Ray Stegeman

²Selk, Glenn. Development of Replacement Beef Heifers. http://agecon.okstate.edu/cattleman/files/ch_21_6th_ed.pdf

³Johnson, Mark Z. Selection of Replacement Heifers. https://extension.okstate.edu/programs/beef-extension/cow-calf-corner-the-newsletter-archives/2024/february-26-2024.html

⁴Rhinehart, Justin D. and Parish, Jane A. Replacement Beef Heifer Development. NRC, 2000. Adapted from NRC Nutrient Requirements of Beef Cattle, 7th revised edition. https://extension.msstate.edu/publications/publications/replacement-beef-heifer-development

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Dingus Honored by Friend of the Beef Reproduction Task Force Award at Recent Symposium

Thu, 24 Oct 2024 14:22:59 GMT

The Beef Reproduction Task Force (BRTF) presented Boyd Dingus with the Friend of BRFT Award on Sept. 4th during the Applied Reproductive Strategies in Beef Cattle Symposium (ARSBC) in Athens, Georgia. This was the first year the Friend of the BRTF Award was presented in recognition of Boyd’s long-term dedication and contributions to the Task Force.

Dingus of Weatherford, Texas, is General Manager of Estrotect and participated in the first meeting that established an educational partnership between industry and academia 20 years ago.

The Beef Reproduction Task Force (academia), together with the national Beef Reproduction Leadership Team (industry and academia), work to promote wider adoption of reproductive technologies among cow-calf producers; educate cow-calf producers in management considerations that will increase the likelihood of successful AI breeding; and educate producers in marketing options to capture benefits that result from the use of improved reproductive technologies.

“The BRTF relies on the financial support of many in the industry to defray costs of our meetings and other activities,” says Sandy Johnson, BRTF member at Kansas State University, “but Boyd’s support has been far beyond that, providing advice, advocacy and encouragement to the group.”

More than 200 producers, veterinarians, and representatives from the artificial insemination (AI) and pharmaceutical industries were in attendance at this year’s ARSBC. The group’s mission is to optimize the productivity and improve the profitability of cow-calf operations by facilitating the adoption of cost-effective, applied reproductive technologies. The goal is to educate beef cattle producers on sustainable reproductive management systems to maintain U.S. leadership and competitiveness in the world beef market.

For more information about this year’s symposium, visit www.BeefRepro.org .

Needle Selection Important for Breeding Synchronization Protocols

Tue, 22 Oct 2024 14:57:21 GMT

Needle size matters depending on the type of substance being administered to cattle. In a recent DocTalk episode, Veterinarian Kirk Ramsey shares things to consider when using hormones during synchronization protocols for breeding cattle.

“Synchronization protocols always require a hormone injection, and there are a few really important factors that we have to remember when approaching hormone injections in cattle,” says Ramsey, who works for Neogen Cattle North America. “All hormone injections of prostaglandin analogs have to be given in the muscle. If those injections fail to get in the muscle, they’re definitely not going to be as effective, and they’re probably going to lead to synchronization failure.”

Needle length and gauge are important depending on the size of the animal. Ramsey says the best rule of thumb is to stick with a one-and-a-half-inch needle for intramuscular injections of hormones.

“The gauge of the needle is a little bit less critical, but the longer the needle, the more likely they are to bend or break, making these injections dangerous to the injector as well as the animal,” Ramsey states.

For most cattle injections, Ramsey recommends an 18-gauge or 16-gauge needle when giving these injections.

In addition, producers should always follow Beef Quality Assurance guidelines for injection sites, which means the injections are best given in the muscles of the neck.

“Hormones associated with cattle synchronization can be very dangerous,” Ramsey explains. “It’s good practice not to handle these hormones if you are pregnant or maybe pregnant, and always wear gloves and protective equipment when giving these injections.”

Your next read: What Needle Size To Use When Working Cattle

Synchronizing Cows With One Injection, One Time Through Chute and Bull Breed

Tue, 22 Oct 2024 14:56:05 GMT

By using this protocol, producers can achieve more calves born earlier in the season without increased labor, cost and facilities using estrus synchronization and artificial insemination. The protocol shown (Figure 1.) can increase the number of cows coming into estrus early in the breeding season, with one time through the chute, one injection, and breeding using only natural service.

Protocol for using one shot of prostaglandin to synchronize estrus and the use of only natural service.

(UNL)

This protocol calls for bulls to be turned out with the cows on Day 0. On Day 5, cows are given a shot of prostaglandin (PGF2α) which synchronizes a majority of the cows to be in heat/estrus from Day 6 through Day 10. The injection of prostaglandin causes any cows with a corpus luteum present on one of their ovaries to regress, ceasing progesterone production. This then triggers the cows to come into heat/estrus.

If the cow conceives during Day 1 to 5, she will not abort when given the prostaglandin injection on Day 5 because the developing corpus luteum at the site of ovulation on the ovary has not yet reached maturity and will not respond to prostaglandin.

Research conducted at the Fort Keogh Research Center near Miles City, Mont., utilized this protocol over a three year period, achieving pregnancy rates over 85% in a 32-day breeding season. Research from the University of Nebraska showed 75% of cows calved in the first 21 days of the calving season utilizing this estrus synchronization protocol as compared to only 63% of cows from non-synchronized natural service breeding.

Utilizing natural service with this method of estrus synchronization will require adequate bull power. A bull to cow ratio of 1:15 with yearling bulls or 1:25 with mature bulls should be sufficient. Because early breeding and the synchronized estrus is occurring over a 10 day period, fertile and active bulls with adequate libido should be able to handle the number of cows that will be coming into heat. Breeding bulls should undergo a breeding soundness exam prior to the breeding season.

Producers considering the use of this synchronization tool should remember that a number of factors affect pregnancy rate including cow body condition score, plane of nutrition, cattle health, and bull fertility.

Estrus synchronization can shorten the calving season. The article “ Use of Natural Service Sires with Synchronized Estrus ” highlights other advantages of estrus synchronization and natural service.

Note: A relatively new prostaglandin product, which is in a high-concentration formula, allows for a 2-mL dose to be injected subcutaneously (under the skin). Other prostaglandin products have an intramuscular injection (IM) label requirement, which requires a longer needle for deep muscle penetration. IM injections have a greater risk to develop lesions in the muscle that affects meat quality. The 2018 Nebraska Beef Report article “ Comparison of Two Alternate Prostaglandin Products in Yearling Beef Heifers ” showed beef heifers performed similarly to either the IM injection of prostaglandin or the subcutaneous injection of high-concentration prostaglandin.

For more information visit UNL Beef .

Your Next Read: Needle Selection Important For Breeding Synchronization Protocols

Biology Lag Time Influences Heifer Retention

Mon, 14 Oct 2024 17:38:21 GMT

It is evident the pace of expansion of the U.S. cow inventory will be slower than past cycles. Several factors will continue to contribute to the slow rebuild. Our beef cow inventory continues to tighten and pushes market prices to record levels. With regard to heifer retention, the questions most of us are asking:

Will increased heifer retention (at some point in the future) result in even higher prices?
How long will these prices last?

Good questions. Past cattle cycles indicate the answer to the first is most likely yes. When producers begin to retain more heifers to develop as herd replacements, it results in fewer calves going to market.

The answer to the second questions is this week’s topic. The biological time lag of beef production. The reality of beef production is that what competing animal proteins can accomplish in weeks (broiler production) or months (pork production), will take those of us in the cow-calf sector years to accomplish. The biology of the beef animal is why.

The Time Line
If we selected a high percentage of our spring (2024) born heifer calves to develop as replacements this fall. Next spring (2025), those properly developed replacement heifers would be ready to breed by 14 – 15 months of age. The following spring (2026), those heifers would calve at two years of age. Those calves would be ready to market at weaning in the fall of 2026. Those calves would become yearlings in 2027 and eventually become marketed as finished “A Maturity” finished cattle or beef carcasses six to seven months after entering the feedyard.

Bottomline
As of now there is little evidence of large scale heifer retention across the country. If and when we begin to retain heifers (on a large scale) we are a couple of years away from increasing the cow inventory, and at least 30 months away from increasing the supply of weaned calves, and so on, regarding yearlings and fed cattle. As is always the case in the beef cattle industry, other factors can and will have impact on the market. That being stated, the basic fundamentals of supply and demand favor strong prices for all categories of cattle until cow inventory begins to increase, and that will take some time.

How Long Should the Voluntary Waiting Period Be?

Thu, 04 Apr 2024 11:51:08 GMT

This article was written by Emily Fread, Extension Educator for Dairy, Penn State University.

The Voluntary Waiting Period (VWP) is the time between calving and when a farmer chooses to rebreed that cow. A VWP of 60 days is used to calculate daughter pregnancy rate and is a standard throughout the dairy industry (VanRaden et al., 2004). Delaying breeding allows for uterine involution to occur and time for cows to recover from a negative energy balance after they freshen.

Some farms have trouble reaching a VWP goal of 60 days; others consciously choose to extend the VWP. A study looking at Dairy Herd Improvement (DHI) records from across the country showed that the median days to first service was 90 days (Miller et al., 2007). VWP is a goal that farmers set on a farm, and days to first service reflects when cows are actually being bred for the first time. This makes days to first service an excellent check to see if the VWP is being met.

Options For Consideration

Some farms may choose to have a longer VWP if they are trying to extend the lactation of high producers. Others may adjust the VWP seasonally, for example, raising it during the summer, as the likelihood of conception is lower. Some farms may consider lengthening the VWP if they do not have enough labor for increased calvings or want to decrease the number of calves coming onto the farm (Burgers et al., 2022). Another reason for extending the VWP is to allow the reproductive tract more time to return to normal after calving.

Many studies have examined the economic impact of different VWP lengths. The most profitable VWP has been found to be less than 70 days, but it is still profitable as long as it is greater than 42 days (Inchaisri, 2011). Some economic studies have examined primiparous vs. multiparous animals, as parity may play a role in an ideal VWP. One study showed that having a longer VWP for first lactation animals is better economically (Weller and Folman, 1990).

Another study comparing the economic viability of extending the VWP for primiparous vs. multiparous cows showed it’s only financially viable for primiparous animals. This was because when multiparous cows VWP increased from 60 to 88 days, they were more likely to leave the herd (Stangaferro et al., 2018).

Consider Primiparous Cows

Farmers may consider extending the VWP for primiparous cows because they often experience a more significant negative energy balance after calving than multiparous cows due to the energy they put towards growth (Fodor et al., 2019). Another study showed that a longer VWP for primiparous animals leads to a greater first-service conception rate and fewer inseminations per conception (Rasmussen, 2023).

There is not much evidence supporting shortening the VWP below 60 days. Uterine involution takes about 42 days in primiparous cows and 50 days in multiparous cows to occur (Buch et al., 1955). Breeding cows before this happens is bound to be unsuccessful. It is an industry standard to breed cows for the first time before 80 days in milk and have them bred by 120 days in milk. This helps maintain a consistent calving interval of 12 to 13 months. Depending on the goal VWP, days to first service may vary from farm to farm.

Troubleshooting should occur if a farm is not reaching its goal and its days to first service are very high. A farmer should start by assessing whether or not they are missing heats. If heats are being missed, additional labor may be required to spend more time checking animals. A synching protocol may be necessary if increased time checking heats doesn’t solve the problem.

A Poor Transition Program

Technologies such as activity monitors can also help with heat detection. If heat detection is not the problem, it could be a scheduling issue with an A.I. technician. If a farm is not having trouble breeding cows for the first time before 80 days but is having a hard time with conception rates at this first service, they may need to assess the transition program and body condition scores of their cows. Cows that are too thin or fat will have conception issues, which can be a sign of a poor transition program.

When a farm decides on what VWP to set, it must first think about the long-term goals of the operation. A farm may be trying to increase conception rates, decrease transition problems, or extend milk production as long as possible. Depending on a farm’s goals, a 60-day VWP may be appropriate, or a longer one may be necessary. VWP is only one management factor that can affect reproductive and lactation performance. The VWP set can impact the calving interval and length of lactation. No matter what a farm’s VWP is, checking if they are meeting their goal regularly is essential. Looking at average days to first service can indicate how close they are to the target VWP.

References
Buch, N. C., W. J. Tyler, and L. E. Casida. 1955. Postpartum estrus and involution of the uterus in an experimental herd of Holstein-Friesian cows. J. Dairy Sci. 38:73-79.

Burgers, E. E. A., A. Kok, R. M. A. Goselink, H. Hogeveen, B. Kemp, and A. T. M. van Knegsel. 2022. Revenues and costs of dairy cows with different voluntary waiting periods based on data of a randomized control trial. J. Dairy Sci. 105:4171-4188.

Fodor, I., G. Gabor, Z. Lang, Z. Abonyi-Toth, and L. Ozsvari. 2019. Relationship between reproductive management practices and fertility in primiparious and multiparous dairy cows. Can. J. Vet Res. 83:218-227.

Inchaisri, C., R. Jorritsma, P. L. A. M. Vos, G. C. van der Weijden, and H. Hogeveen. 2011. Analysis of the economically optimal voluntary waiting period for first insemination. J. Dairy Sci. 94:3811-3823.

Miller, R. H., H. D. Norman, M. T. Kuhn, J. S. Clay, and J. L. Hutchison. 2007. Voluntary Waiting Period and Adoption of Synchronized Breeding in Dairy Herd Improvement Herds. J. Dairy Sci. 90:1594-1606.

Rasmussen, A. E., R. Bage, K. Holtenius, E. Strandberg, C. von Bromssen, M. Akerlind, and C. Krongvist. 2023. A randomized study on the effect of an extended voluntary waiting period in primiparious dairy cows on fertility, health, and culling during first and second lactation. J. Dairy Sci. 106:8897-8909.

Stangaferro, M. L., R. Wijma, M. Masello, M. J. Thomas, and J. O. Giordano. 2018. Economic performance of lactating dairy cows submitted for first service timed artificial insemination after a voluntary waiting period of 60 or 88 days. J. Dairy Sci. 101: 7500-7516

VanRaden, P. M., A. H. Sanders, M. E. Tooker, R. H. Miller, H. D. Norman, M. T. Kuhn, and G. R. Wiggans. 2004. Development of a national genetic evaluation for cow fertility. J. Dairy Sci. 87:2285-2292.

Weller, J. I., and Y. Folman. 1990. Effects of calf value and reproductive management on optimum days to first breeding. J. Dairy Sci. 73:1318-1326.