Veterinary Education

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

Tue, 07 Apr 2026 22:54:01 GMT

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

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

A Common Problem, Often Hidden

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

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

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

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

(Farm Journal)

Total Versus Ionized Calcium: A Critical Distinction

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

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

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

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

A Shift in Thinking: Hypocalcemia as Part of Immunity

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

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

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

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

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

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

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

(Farm Journal)

Endotoxin: A Likely Trigger

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

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

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

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

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

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

Calcium as an Active Player in Immunity

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

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

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

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

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

Current Strategies

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

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

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

What This Means for Veterinarians and Producers

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

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

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

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

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

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

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

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

4 Tips for Assessing Hydration Status in Calves

Fri, 20 Feb 2026 14:56:41 GMT

Assessing dehydration status is the first step in managing a scouring calf, but it’s not as simple as assigning a percentage. Dehydration, acidemia and neurologic function do not progress at the same rate. A calf may not look profoundly dehydrated but still require intravenous correction.

Speaking at the AABP Recent Grad conference, Dr. Blake Balog, professional services veterinarian with TELUS Agriculture, outlined some tips for assessing hydration status in calves.

1. Start with the Eye

Globe recession remains one of the most reliable field indicators of dehydration, but only if it is measured correctly.

Balog recommends rolling down the lower eyelid to look for space.

“Make sure when you’re assessing that you’re rolling that lower eyelid out to a more normal position and measure that depth,” Balog says. “If it’s hitting somewhere in the 4 mm range, that’s going to be close to 8% dehydration, which is the point where we want to use IV fluids.”

Measure deliberately and determine whether oral fluids will be enough.

2. Check Peripheral Profusion

As dehydration progresses, circulation shifts centrally and causes the extremities to cool. While you could invest in an infrared thermometer, using your hands to feel whether the peripheral distal limbs are cold or cool will likely suffice.

Cold limbs alone may not indicate dehydration, but they certainly reinforce that it may be the case.

3. Separate Dehydration from Acidemia

“The level of dehydration doesn’t always linearly go along with the level of acidemia,” Balog says.

This is a crossroads at which decisions can go wrong. A calf may not appear severely dehydrated and still be acidemic. Relying on percent dehydration alone can miss calves that require escalation.

Balog suggests testing the palpebral reflex.

“When you tap that medial canthus and you get a delayed or sluggish palpebral reflex, that’s an indicator of lactic acid that’s accumulated in that animal,” Balog says.

Delayed reflexes, weakness and failure to suckle suggest metabolic compromise. If the calf cannot suckle, oral therapy alone is unlikely to be enough.

4. Use Supporting Findings

Urine concentration can reinforce your assessment. If a refractometer is available, specific gravity could be used. Otherwise, dark, concentrated urine supports systemic dehydration.

Skin tenting is another quick way to evaluate hydration. Pinch a fold of skin on the neck or around the eyes and count the number of seconds it takes to flatten. Skin flattening in less than 2 seconds indicates normal hydration, 2 to 5 seconds to flatten indicates 8% dehydration and over five seconds would indicate severe dehydration over 10%.

Placing an IV Catheter in Calves

Placing an IV catheter in a dehydrated calf can be more difficult because the skin is thick and the jugular vein does not present well.

Balog recommends focusing on mechanics.

Position the head on a downward slope.
“We’re going to have the head of that calf dropping downward. That’s going to help fill the jugular vein a little bit easier,” Balog says.

Lowering the head improves venous fill and simplifies placement.
Clip and prep generously.
Dehydrated skin offers more resistance. A wide clip and thorough prep make catheter passage smoother.
Perform a cut down incision.
“This is the key part that I think we’ll struggle with: Not doing a cut down. Cut down to me is not sawing with the scalpel blade down toward the jugular. We’re going to tent the skin up and we’re going to go straight down with our 22 blade until it finally releases through there and then we’re going to lay that down,” Balog says.

This incision is vertical and controlled, not a sweeping motion toward the vein. This is critical in dehydrated calves when the skin is super thick and difficult to get through.
Secure the catheter carefully.
Tape and suture so access remains stable during fluid delivery. Balog likes to use a butterfly catheter secured with a couple sutures. He’ll then do an additional suture up on the head so the line remains straight.

The goal is straightforward: assess accurately and intervene appropriately. When dehydration approaches 8% or acidemia affects function, oral therapy may not be sufficient. At that point, gain access, deliver fluids and reassess.

Bugs Beware: Next Gen Prepares to Combat Insect Threats to Animal Health

Wed, 03 Dec 2025 15:43:36 GMT

The nation is facing a critical shortage of veterinary entomologists. Kansas State University is ramping up efforts to create awareness and opportunity for students interested in playing a crucial role in safeguarding livestock health and agricultural economies by studying insects and ticks that affect animals.

“With increasing insecticide resistance and the emergence of new tick and tick-borne pathogen species, our capacity to meet future research, extension and teaching needs in this area is more critical than ever,” Cassandra Olds, assistant professor of entomology at K-State, says in a release.

To address this increasing challenge, Olds collaborated with other university veterinary entomologists to develop the Research and Extension Experience in Veterinary Entomology for Students (REEVES) program .

“Despite the significant impact arthropods like ticks and insects have on livestock production, there’s a serious lack of trained veterinary entomologists,” Olds says. “Many students simply aren’t aware of this viable career path or what it entails.”

Funded by the USDA-NIFA and led by the University of Tennessee, the 8-week summer residential program offers an immersive, hands-on experience in veterinary entomology research and extension.

“The overarching goal of REEVES is to introduce and train talented individuals for graduate and professional programs, as well as livestock-associated careers that emphasize team science,” the release says. “The program educates them on the fundamentals of veterinary entomology and provides them with real-world project experience relevant to the needs of stakeholders.”

Two scholars are placed at each participating institution each year, K-State, University of Tennessee, Texas A&M and University of Georgia, and will run from 2025 till 2028.

Not only will REEVES scholars engage in impactful research, but they will also have the opportunity to present their research at the annual Livestock Insect Workers Conference and an online REEVES Expo. For example, K-State scholars evaluated the impact of stable flies on cattle performance in feedlots this year and investigated recent outbreaks of Theileria orientalis in the region.

“For me, the most exciting aspect of this field is the chance to do good at every level,” Olds adds. “You have the opportunity to positively impact both animal health and well-being, while simultaneously improving the livelihoods of the people who own them.”

Seeing the Whole Elephant: Systems Thinking and Animal Health

Mon, 24 Nov 2025 22:19:50 GMT

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

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

Why Looking Closely Isn’t Enough

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

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

Examples crop up everywhere:

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

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

Systems Thinking: Looking Between the Parts

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

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

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

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

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

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

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

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

The Veterinarian as a Systems Navigator

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

This means asking broader questions:

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

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

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

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

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

Case Example: Reframing a ‘Simple’ Mastitis Problem

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

Teat-end condition
Milking protocols
Bedding
Culture results

A systems approach goes further:

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

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

Stepping Back to See the Elephant

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

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

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

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

Mooving Cows: A New Approach to Training Cow Handling

Thu, 13 Nov 2025 21:35:24 GMT

Veterinarians have long been advocates for animal welfare, not only in treatment, but in dairy management. Yet one of the most significant welfare determinants on dairy farms often lies outside the treatment pen: how cows are moved and handled. Cow-handling practices directly affect stress physiology, lameness risk, udder health, milk let-down and handler safety. Veterinarians are uniquely positioned to influence these routines.

Studies consistently show the way cows are approached, moved and restrained has measurable impacts on cortisol levels, heart rate and behavior. Handling stress can compromise immune function, increase the incidence of masitis and interfere with reproduction. Conversely, calm, predictable handling improves milk yield and reduces fear responses over time.

Proper cow handling is not just good practice in welfare terms, but it is central to safe farms and productive herds.

When Jennifer Van Os from the University of Wisconsin-Madison spoke with producers, the need for education on animal handling became clear.

“I met with a bunch of Wisconsin dairy farm owners and managers to ask them about some of the challenges that they face with animal care and animal welfare,” Van Os says. “One of the most popular requests that I got was: Can you please come to my farm and train my staff on proper handling?”

Unfortunately, this wasn’t feasible, but she took the message to heart and considered what she could do to address the request.

Reimagining Animal Handling Training

Enter a clever training twist: the serious game ‘Mooving Cows’. Developed by Van Os and the animal welfare team at the University of Wisconsin, this digital touchscreen game enables farm staff (and anyone interested) to practice moving cows in a simulated dairy farm environment. Van Os and colleagues conducted research with four focus groups including farm staff and decision-makers (farm owners, veterinarians) on the game prototype to help shape the 1.0 release.

“Animal handling is really important for animal welfare, as well as other aspects of productivity and profitability on the farm,” Van Os says. “We know that when we handle cows appropriately, this can reduce the risk of injury, both to the cows themselves and to the people who work with them. We also know that when we handle them appropriately, it reduces cow stress levels, which then helps with milk yield as well as efficiency in the milking parlor.”

Rather than simply reading a manual, trainees play through a series of scenarios: moving cows from pasture to barn, guiding them into the milking parlor and navigating when a cow is reluctant. The game rewards patience, calm movements and minimal startling gestures, while it penalizes rushing, shouting or forcing cows into motion. In effect, it applies the principles of low-stress livestock handling in a safe, virtual form: pressure and release, staying on the edge of an animal’s flight zone, moving at a walk and staying in the cow’s line of sight.

One of the key aspects of the application is the opportunity for failure.

“There is this principle in educational video games that it provides this safe environment where you can deliberately mess up,” Van Os explains. “It provides an opportunity for you to learn by making mistakes or learn by failure, and that’s something you can’t necessarily do in training. If it’s hands-on and active and interactive, there are real life stakes where you don’t want to get injured and you don’t want the animals getting stressed or injured.”

Research performed by Van Os’ group shows users found that the application to be an easy-to-use training tool and knowledge of best cow handling practices improved after playing through the game.

‘Mooving Cows’ is completely free and is available for both Apple and Android devices. The application has been approved by the Farmers Assuring Responsible Management (FARM) Animal Care program for continuing education on stockmanship; completion of the game provides users with a certificate.

Van Os and her team hope to continue developing interactive, gamified cow handling applications with their sights set on training for maternity pens, the parlor and down cows.

A Unique, Hands-On Approach to Training Tomorrow’s Dairy Veterinarians

Wed, 06 Aug 2025 19:34:28 GMT

Large animal veterinarians specializing in dairy have almost become the unicorns of the industry. In a space that is nearly dominated by small animal vets, finding young professionals interested in pursuing a dairy-focused practice has become increasingly rare. That’s why hands-on programs like the University of Vermont’s CREAM Program (Cooperative for Real Education in Agricultural Management), are playing a vital role in developing the next generation of dairy veterinarians.

Stephen Wadsworth, the current director of CREAM, brings more than four decades of dairy veterinary experience to the role. As a teacher for the Department of Animal and Veterinary Sciences, his background in private practice offers students a direct link between academic concepts and real-world applications in dairy herd management.

“The CREAM program was started in 1988 by an animal geneticist on faculty,” Wadsworth explains. “It’s a 60-cow tiestall, high-producing registered Holstein herd, currently averaging about 100 lb. per day, and it’s run almost exclusively by undergraduate animal science students, most of whom are pre-vet and have never even handled a dairy cow before.”

What began as a temporary teaching position in 2018 quickly became a full-time role that Wadsworth calls more rewarding than he ever expected. After four decades in a busy, six-person dairy practice in northwestern Vermont, he welcomed the opportunity to pass on his knowledge to those just entering the profession.

“Though I should be retired, it’s too much fun,” he says. “It’s been far more gratifying than I imagined.”

Beyond the Books: Learning by Doing
According to Wadsworth, the CREAM program offers more than just basic classroom learning. Students participate in every aspect of managing the university’s dairy herd, from milking and feeding to reproductive protocols and record-keeping. The immersive experience prepares them for future roles in veterinary school and beyond.

Currently, the program is divided into three core areas: academic instruction, work skill development, and community and personal growth.

“First, there’s lecture, about two and a half hours per week where I cover livestock medicine, herd health and management principles,” Wadsworth says. “Second is work skill development. Many of these students have never held jobs requiring punctuality or responsibility. So, they learn that when we say you have to be here at 3:30 a.m. for morning milking, it really means 3:20 a.m., or preferably 3:15 a.m. to set up the parlor.”

He adds that the third area, community and personal development, might be the most impactful.

“We talk about what it means to be a person of good character and how to work together in a group,” Wadsworth says, noting how the first few days learning how to operate a dairy is challenging for the students.

“You’ve got 20 students working together to milk 60 cows in a double-six parlor. Some days it’s like herding cats,” he laughs. “The first milking during the summer took seven hours, but now they’re down to an hour and a half. But in a few weeks, there’s this tight community and new friendships formed, and students leave the program saying it was the most transformative thing they’ve ever done in their life.”

While the program serves as a steppingstone for students applying to veterinary school, it often leads to a deeper transformation.

“Some students come in thinking this is just a box to check for their application,” Wadsworth says. “But many convert to being interested in a dairy practice. When they are accepted into vet school, many decide to pursue a career in dairy medicine as a result of their time here, which is gratifying beyond words.”

As the veterinary profession continues to evolve, programs like CREAM offer an essential on-ramp for students with little or no agricultural background.

“We know there isn’t necessarily a shortage of food animal veterinarians, but we do have geographic placement challenges,” Wadsworth says. “And fewer young people are growing up on farms. So, it’s vital to provide this kind of exposure to what dairy farming really looks like.”

That exposure includes full responsibility for the daily care of the UVM CREAM herd. Students handle all aspects of herd management, including milking three times per day as well as cleaning, feeding calves and administering medical treatments under guidance. Each student completes three to four chores weekly, one of which always includes the early morning milking. They’re also involved in calving, fresh cow and calf care, vaccinations and reproductive synchronization. Additionally, every student is assigned a specialty area and expected to keep the group informed on that topic throughout the program.

Wadsworth is careful to emphasize the skills students gain are universally applicable across herd sizes and management systems.

“If you understand the biology of a cow — the physiology of ketosis, reproduction and mastitis — those fundamentals apply whether you’re on a 60-cow tiestall or a 6,000-cow commercial dairy,” he says. “It may look different, but the principles are the same.”

To add to this experience, Wadsworth is currently organizing a six-farm tour for his students to further broaden their exposure to different dairy operations across northern Vermont.

“It gives them the opportunity to see firsthand how those principles scale and adapt,” he says. “The goal is to provide a strong foundation so they can walk into any herd and understand what’s happening.”

For students without previous large-animal experience, the smaller scale of the CREAM herd offers an ideal environment to build confidence and competence.

“You could argue that animal handling and husbandry are easier to learn in a 60-cow herd than a larger operation,” Wadsworth notes. “But here, they have more direct contact with the animals and more opportunities to take ownership of daily tasks. That kind of engagement really accelerates learning.”

For Wadsworth, transitioning from private practice to academia has brought a new and refreshing challenge.

“I feel privileged to be here,” he says. “Watching these students grow over the course of the program is something special.”

As the veterinary industry looks to the future, programs like CREAM are helping ensure the next generation of dairy veterinarians are equipped with knowledge, hands-on experience and respect for the work ahead.

To learn more about UVM’s CREAM Program, watch here:

Second Bird Flu Strain Found in U.S. Dairy Cattle, USDA says

Thu, 06 Feb 2025 14:36:48 GMT

U.S. dairy cattle tested positive for a strain of bird flu that previously had not been seen in cows, the U.S. Department of Agriculture said on Wednesday, ramping up concerns about the persistent spread of the virus.

The H5N1 virus has reduced milk output in cattle, pushed up egg prices by wiping out millions of hens, and infected nearly 70 people since April as it has spread across the country.

Genome sequencing of milk from Nevada identified the different strain, known as the D1.1 genotype, in dairy cows for the first time, the USDA said. Previously, all 957 bird flu infections among dairy herds reported since last March had been caused by another strain, the B3.13 genotype, according to the agency.

Reuters reported news of the detection of the second strain on Wednesday ahead of USDA’s announcement.

The second strain was the predominant genotype among wild birds this past fall and winter and has also been found in poultry, the USDA said. It was identified in dairy cattle through an agency program that began testing milk for bird flu in December.

“We’re seeing the H5N1 virus itself be smarter than all of us,” said Beth Thompson, South Dakota’s state veterinarian.

“It’s modifying itself so it’s not just staying in the poultry and the wild waterfowl. It’s picking up a home in the mammals.”

Wild birds likely transmitted the second strain to cattle in Nevada, said J.J. Goicoechea, Nevada’s agriculture director. Farmers need to ramp up safety and security measures to protect their animals, he said.

“We obviously aren’t doing everything we can and everything we should or the virus wouldn’t be getting in,” he said.

“We didn’t get a hold on it before,” Hansen said. “We want to avoid that same scenario from happening in Nevada.”

Dairy herds that were formerly infected may be at risk again from the second strain, experts said.

“Now it looks like we have new strains of virus that may escape some of the immunity associated with the other strains of viruses that could exacerbate the epidemics among animals and wildlife,” said Gregory Gray, a University of Texas Medical Branch professor studying cattle diseases. “It’s alarming.”

Your Next Read: Beef-on-Dairy: A Critical Solution to the Shrinking U.S. Cattle Herd

USDA Announces New Federal Order, Begins National Milk Testing Strategy to Address H5N1 in Dairy Herds

Fri, 06 Dec 2024 19:32:32 GMT

Today, the U.S. Department of Agriculture’s (USDA) Animal and Plant Health Inspection Service (APHIS) is announcing the start of its National Milk Testing Strategy (NMTS), which builds on measures taken by USDA and federal and state partners since the outbreak of highly pathogenic avian influenza (HPAI) H5N1 in dairy cattle was first detected in March 2024. Today, USDA is issuing a new Federal Order, as well as accompanying guidance, requiring that raw (unpasteurized) milk samples nationwide be collected and shared with USDA for testing. This new guidance from USDA, which was developed with significant input from state, veterinary and public health stakeholders, will facilitate comprehensive H5N1 surveillance of the nation’s milk supply and dairy herds.

“Since the first HPAI detection in livestock, USDA has collaborated with our federal, state and industry partners to swiftly and diligently identify affected herds and respond accordingly. This new milk testing strategy will build on those steps to date and will provide a roadmap for states to protect the health of their dairy herds,” said Agriculture Secretary Tom Vilsack. “Among many outcomes, this will give farmers and farmworkers better confidence in the safety of their animals and ability to protect themselves, and it will put us on a path to quickly controlling and stopping the virus’ spread nationwide. USDA is grateful to our partners who have provided input to make this strategy effective and actionable, and we look forward to continued collaboration in seeing this through.”

This NMTS is designed to increase USDA’s and public health partners’ understanding of the virus’ spread in the United States through a structured, uniform, and mandatory testing system that will help swiftly identify which states, and specific herds within them, are affected with H5N1; support the rapid implementation of enhanced biosecurity measures to decrease the risk of transmission to other livestock; and importantly, inform critical efforts to protect farmworkers to help lower their risk of exposure. USDA believes this additional step is needed to proactively support effective biosecurity measures, which is key for states and farmers to contain and eliminate H5N1 infections from their livestock and to eliminate HPAI in livestock across the U.S. dairy population.

“This testing strategy is a critical part of our ongoing efforts to protect the health and safety of individuals and communities nationwide,” said HHS Secretary Xavier Becerra. “Our primary responsibility at HHS is to protect public health and the safety of the food supply, and we continue to work closely with USDA and all stakeholders on continued testing for H5N1 in retail milk and dairy samples from across the country to ensure the safety of the commercial pasteurized milk supply. We will continue this work with USDA for as long and as far as necessary.”

The Federal Order released today makes three new requirements. First, it requires the sharing of raw milk samples, upon request, from any entity responsible for a dairy farm, bulk milk transporter, bulk milk transfer station, or dairy processing facility that sends or holds milk intended for pasteurization. Second, the Federal Order requires herd owners with positive cattle to provide epidemiological information that enables activities such as contact tracing and disease surveillance. Finally, like USDA’s April 24 Federal Order, it requires that private laboratories and state veterinarians report positive results to USDA that come from tests done on raw milk samples drawn as part of the NMTS. The first round of silo testing under the Federal Order and the NMTS is scheduled to begin the week of Dec. 16, 2024, although some states are already conducting testing compatible with the NMTS.

This new Federal Order does not override or supersede USDA’s April 24 Federal Order , which still requires the mandatory testing of lactating dairy cows prior to interstate shipment and requires that all privately owned laboratories and state veterinarians report positive test results connected with those tests. The new Federal Order announced today is intended to complement and enhance this existing order.

National Milk Testing Strategy

As part of the National Milk Testing Strategy, APHIS will work with each state in the contiguous United States to execute testing in a way that works for the state and that aligns with the NMTS standards. Once a state begins testing under the NMTS, APHIS will place that state into one of five stages based on the HPAI H5N1 virus prevalence in that state. As states move to another stage, we will have a stronger picture of our progress towards eliminating HPAI H5N1 at state, regional and national levels. These stages include:

Stage 1: Standing Up Mandatory USDA National Plant Silo Monitoring

USDA will immediately begin nationwide testing of milk silos at dairy processing facilities. This national sample will allow USDA to identify where the disease is present, monitor trends, and help states identify potentially affected herds.

Stage 2: Determining a State’s H5N1 Dairy Cattle Status

Building on the results of silo monitoring, in collaboration with states, USDA will also stand up bulk tank sampling programs that will enable us to identify herds in the state that are affected with H5N1.

Stage 3: Detecting and Responding to the Virus in Affected States

For states with H5N1 detections, APHIS will work quickly to identify specific cases and implement rapid response measures, including enhanced biosecurity using USDA’s existing incentives programs, movement controls and contact tracing.

Stage 4: Demonstrating Ongoing Absence of H5 in Dairy Cattle in Unaffected States

Once all dairy herds in a given state are considered to be unaffected, APHIS will continue regular sampling of farms’ bulk tanks to ensure the disease does not re-emerge. Bulk tank sampling frequency will progressively decline as the state demonstrates continual silo negativity (e.g., weekly, monthly, quarterly if continually negative). If a state becomes affected, USDA will re-engage detection and response activities, and the state will return to Stage 3.

Stage 5: Demonstrating Freedom from H5 in U.S. Dairy Cattle

After all states move through Stage Four, APHIS will work with the states to begin periodic sampling and testing to illustrate long-term absence from the national herd.

As of this announcement, the following six states will be included in the first round of states brought into the program for testing: California, Colorado, Michigan, Mississippi, Oregon, and Pennsylvania.

As states begin testing under the NMTS and as they move through the five stages, their progress will be shared at USDA HPAI in Livestock Testing . While the majority of states will enter the NMTS at Stage 1, we anticipate states with ongoing testing may meet the testing requirements described above in Stages 2-4. USDA will work closely with states to determine each state’s status. While the majority of states will enter the NMTS at Stage 1, we anticipate states with ongoing testing may meet the testing requirements described above in Stages 2-4. USDA will work closely with states to determine each state’s status.

Webinars and Additional Information

USDA will co-host information sessions for all state animal health officials and state dairy regulators the week of Dec. 9 to learn more about the National Plant Silo Monitoring and sampling procedures. These sessions are scheduled for Tuesday Dec. 10 and Wednesday Dec. 11 to allow multiple opportunities for dairy regulators and industry stakeholders to participate.

APHIS has been working diligently to educate and inform key state and animal health partners about this Federal Order and National Milk Testing Strategy, as well as to establish written agreements with states to support how they can work with USDA under the new strategy.

APHIS has also sought and received input from state animal and public health partners about potential needs for the strategy and implementation across their various states, particularly for standardized sampling tools, outreach, and potential personnel and fiscal resources from USDA.

In the coming weeks, APHIS will include additional states in the NMTS. Throughout this process APHIS will continue to support and offer resources to states that develop bulk milk testing plans in a way that meets the needs of each state and the importance of the response. APHIS will work with each of the 48 contiguous states to participate in the program.

USDA’s Multifaceted Effort to Address H5N1

Since confirming the initial H5N1 infections in cattle in March 2024, USDA has taken significant steps to better understand and control the virus’s spread. This response was aided by APHIS’ more than 50 years of experience in research and managing influenzas across other animal species, and by long-standing partnerships with state animal health officials that allow for the swift establishment of all testing and response activities. APHIS and state partners have seen significant success in responding to detections identified through state-level testing programs, and the NMTS builds on these efforts and will better identify the prevalence of the virus and guide response steps nationwide.

USDA has provided all H5 livestock testing through the NAHLN laboratory network, free of charge, regardless of whether it was performed for pre-movement testing under the current Federal Order; through the Dairy Herd Status Program; under testing programs that some states have designed pursuant to their unique authorities; prior to intrastate movement to fairs, exhibitions, or sales as part of state testing programs; or for producers interested in learning the status of their livestock herds. As a result of this testing, USDA has received samples from each of the 48 contiguous states over the course of this outbreak, with all confirmed positive findings being reported through the APHIS website, and whole genome sequences of each detected virus uploaded to public databases.

USDA continues to stress to farmers nationwide that effective biosecurity practices are the best weapon against the spread of disease, and that all farms should review their current biosecurity measures and ensure best practices identified over the past eight months are incorporated, even if H5N1 has not been detected in their state or region.

USDA strongly encourages herd owners to participate in the already available producer support programs, which help to cover the cost such as biosecurity programming, PPE for employees, and veterinary care. Producers can find more information at Financial Assistance | Animal and Plant Health Inspection Service , or at your nearest USDA Farm Service Agency county office .

USDA Research Related to H5N1 in Dairy Cattle

USDA has been working collaboratively with its federal partners at HHS to better understand the origin of the emergence of the virus and its potential impact in both bovines and humans. USDA has leveraged its laboratories, researchers, and regulatory agencies to address this issue and, in partnership with FDA, help ensure the safety of our nation’s food supply. This includes lab and personnel support for FDA-designed studies to test the safety of milk and dairy products and reaffirm the efficacy of pasteurization for the safety of products on retail shelves. USDA FSIS has also completed a series of studies on beef , which demonstrate that safely cooking beef inactivates the H5N1 virus, if present. USDA APHIS has also prepared and shared two separate epidemiological reports on the virus and its spread, which can inform biosecurity practices and next steps.

To learn more about USDA’s response to HPAI in dairy cattle, visit www.aphis.usda.gov/livestock-poultry-disease/avian/avian-influenza/hpai-detections/livestock .

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Protecting Potency: Best Practices for Effective Vaccine Storage on the Farm

Tue, 03 Dec 2024 21:16:57 GMT

Vaccines are only as effective as the conditions in which they are kept. That’s why paying a bit of extra attention to storage can go a long way when it comes to ensuring these immunizations do their job.

According to Curt Vlietstra, DVM at Boehringer Ingelheim, improper storage or handling can result in ineffective vaccines. Temperature fluctuations, exposure to light and improper handling can all impact a vaccine’s potency, reducing its protective power. Vlietstra advises farmers to pay close attention to vaccine storage conditions to help maintain effectiveness.

Top Vaccine Storage Pitfalls

Vaccines are sensitive biological substances that need specific conditions to maintain their potency. Three issues Vlietstra commonly sees when it comes to vaccine storage include:

Improper Temperature: Most vaccines must be stored between 35°F and 46°F. Any exposure to freezing or excessive heat can denature the active ingredients, making them ineffective.
Exposure to Light: Many vaccines are sensitive to light, which can also degrade their quality. These vaccines should be protected from UV light once removed from the refrigerator.
Expired Vaccines: Use older vaccines first and always check expiration dates. Storing newer stock at the back and keeping older doses at the front makes it easier to avoid using expired vaccines and helps maintain the effectiveness of your supply.

Steps for Proper Vaccine Storage

Vlietstra suggests implementing the following steps to help ensure vaccines are stored properly.

Invest in Reliable Refrigeration: “Don’t go with the cheapest fridge you can find,” Vlietstra advises. Instead, he recommends investing in a quality refrigerator that is designated solely for medical usage.

“I don’t want your lunch or drinks in there because the more time it gets open and closed, the more changes you have in the temperature. Plus, there’s a higher likelihood that it doesn’t get closed all the way.
Use Temperature Monitors: Implement temperature monitoring systems that alert staff if the vaccine storage deviates from the optimal range.

“Usually, a fridge doesn’t go bad overnight,” Vlietstra says. It slowly starts to lose its effectiveness. Having a good thermometer can warn you when your barn fridge is on its way out. Some of these thermometers even have wireless alerts that can connect to an app on your phone.”
Handle With Care: When it comes to vaccine handling, keeping doses at a stable temperature is crucial, even after mixing. Whether it’s hot or cold outside, Vlietstra recommends storing mixed vaccines in a transportable cooler to help protect them from extreme temperature fluctuations and sunlight.

“How we mix, handle and store these vaccines matters,” Vlietstra adds. “Have conversations with your veterinarian and consider implementing a training day to review proper storage and handling SOPs with your team. Regularly refreshing this training ensures everyone is on the same page, which can make a real difference when it comes to herd health.”

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Oregano: Not Just for Pizza Anymore

Mon, 14 Oct 2024 21:05:20 GMT

Move over, pizza and pasta. Oregano – specifically, its essential oil – is finding its way into calf diets.

Oregano essential oil has been shown to have antibacterial properties against Gram-negative bacteria, especially E. coli. It also has been shown to have antiviral and anticryptosporidial effects in laboratory settings.

Two recent studies examined the effects of oregano essential oil in calf diets.

The first study, led by researchers at Aristotle University of Thessaloniki in Greece, examined the effects on early life diarrhea by supplementing newborn calves with Greek oregano essential oil. A total of 91 Holstein calves from three dairy farmers were included.

Half of the calves received a drench of oregano essential oil at 12.5 mg/kg of bodyweight for the first 10 days of life. The other half received no treatment. The researchers noted that, because oregano oil has a strong flavor, they opted for a drench delivery to avoid affecting milk intakes. The oil was diluted with saline solution up to 60 mL.

Results included:

· The overall incidence of diarrhea was significantly lower in the calves receiving oregano oil. That difference was the result of a dramatically lower incidence at one of the farms, which had outstanding hygiene, leading the researchers to speculate that diarrhea incidence was reduced most effectively by oregano oil when pathogen loads were low.

· For calves from all farms, the severity of diarrhea was appreciably lower in the oregano-oil-treated calves. This was the result of a lower number of days with diarrhea, lower diarrhea index, shorter duration of sickness, and fewer calves requiring treatment (antibiotic and supportive therapy).

The researchers speculated that reduced severity of diarrhea in calves treated with oregano oils was due to inhibition of coliform bacteria overgrowth in the small intestine of diarrheic calves, leading to lower incidence of bacteremia.

The second study , conducted at the Gansu Academy of Agricultural Sciences in China, examined the potential of replacing monensin with oregano essential oil in the grower diet of weaned Holstein bull calves. The research team speculated that oregano could provide the same benefits to rumen fermentation as monensin, modulating rumen fermentation and potentially lowering acidosis.

One of four treatments was assigned to three calves each, for a total of 12 calves in the study. Starting at 70 days of age, calves were followed for the next 240 days, receiving (1) no treatment (control); (2) oregano essential oil at 36 mg/kg of dry matter (DM)in the TMR; (3) monensin at 25 mg/kg of DM; and (4) a combination therapy including both the same dose of oregano oil and monensin.

Both the oregano essential oil group and the monensin group had significantly higher weight gain than the other two groups. Interestingly, the lowest weight gain was in the combination therapy group, leading the researchers to believe that the two treatments had an antagonistic effect on one another.

They concluded that using oregano essential oil alone could be a valid alternative to monensin, providing a non-antibiotic alternative that still yielded growth promotion benefits.

Top 10 Veterinary Colleges Announced

Thu, 26 Sep 2024 21:29:40 GMT

If you and friends enjoy bantering about which college of veterinary medicine is best, a new report will simply add more fuel to your conversational fire.

London-based Quacquarelli Symonds (QS) announced its inaugural ranking of the world’s best veterinary colleges in March. At No. 1 globally is the University of California-Davis. Two additional U.S.-based schools round out the top 10, with the remaining seven located in Canada, Denmark, Netherlands, Switzerland and the United Kingdom (UK), respectively. See the complete listing below.

QS says the rankings are based on four factors: academic reputation, employer reputation, research citations and H-index. The latter, QS says, “is a way of measuring both the productivity and impact of the published work of a scientist or scholar.”

QS bills itself as the “world’s leading provider of services, analytics and insight to the global higher education sector.” The rankings were announced in partnership with Elsevier, a Dutch publishing and analytics company. More information on the methodology is available at topuniversities.com.

Top 10 Veterinary Colleges
#1. University of California-Davis

#2. University of London-UK

#3. Cornell University

#4. Utrecht University-Netherlands

#5. University of Guelph-Canada

#6. University of Edinburgh-UK

#7. University of Cambridge-UK

#8. Michigan State University (tie)

#8. Vets Faculty-Switzerland (tie)

#10. University of Copenhagen-Denmark

Other U.S. schools QS says are of interest:

The Ohio State University
University of Minnesota
University of Pennsylvania
Colorado State University
North Carolina State University
University of Wisconsin-Madison
Iowa State University

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Health Traits Have Genetic Heritability in Calves

Mon, 19 Aug 2024 17:32:06 GMT

In the quest to raise healthy, productive, profitable calves comes an emerging element: genetics.

Along with the myriad factors dairy producers embrace to raise the healthiest potential offspring, there is growing evidence that calves can inherit disease resistance from their parents. Thus, traits for resistance to diseases like pneumonia and scours may become an increasingly important factor in dairy genetic selection, according to Dr. Isaac Haagen, Assistant Professor of Animal Science at the University of Minnesota.

Haagen shared his thoughts on dairy calf genetic health traits on a recent episode of The Dairy Podcast Show. He discussed data that he gathered during his graduate studies at Pennsylvania State University, which encompassed 15 organic dairy herds from across the United States, ranging in size from about 30 cows to several thousand.

Specifically, he merged the calf health data from those herds, which was gathered via a variety of herd software platforms. Then, using traditional pedigree analysis and a limited amount of genomic data, he was able to determine that, based on that data set, health traits in calves are heritable to a degree similar to more widely monitored traits like Daughter Pregnancy Rate (DPR) and Productive Life – generally, about 5-10%.

Haagen said that rate is similar to the heritability reported by Zoetis for the Calf Wellness Index^TM (CW$^TM) in their Clarifide® Plus genomic test. The Clarifide Calf Wellness Index encompasses traits for respiratory disease, scours, and calf livability.

A Canadian study recently published in the Journal of Dairy Science further supports the notion that calf diseases can be controlled in part via genetic selection. In that study, records from more than 62,000 dairy calves from 1,617 Canadian herds spanning 2006-2021 were evaluated.

The Canadian researchers found that heritability for respiratory disease and diarrhea ranged from 2-7%. They also discovered that calves born to the bottom 10% of sires for the traits were 1.8 times more likely to develop respiratory disease, and 1.9 times more likely to develop diarrhea, compared to daughters born to the top 10% of sires.

That group advocated for a national recording system to allow for national genetic evaluation, a concept that Haagen also supports in the United States. He said the evidence is strong enough to make the argument for a calf health specific index among the national traits evaluated by the Council for Dairy Cattle Breeding.

“While 5-10% heritability is a relatively small number, we know from other health traits that even that small number can have an impact over many generations,” Haagen stated.

He added that with any selection index, “we’re really selecting for profitability. With heifer replacement costs generally running as the second or third highest expense on farms, there is value in selecting for healthier animals that are expected to live longer.”

An interesting and related factor in Haagen’s research was an analysis he ran on serum total protein (STP) as a health measure. His findings indicated that, in addition to crucial factors like colostrum delivery, STP also is a heritable trait in calves.

“We found that calves differ in their ability to acquire passive immunity,” he stated. When he and his colleagues separated animals according to breeding value for STP, they found that 4-6% more of the heifer calves in the top quartile would remain in the herd at one year of age compared to the worst calves.

Haagen is continuing his research on calf health genetic traits using 20 years’ worth of data on more than 6,000 calves from commercial Minnesota dairy herds. He hopes the longer range of that data will help him extrapolate lifetime performance evidence related to genetic factors for calves, providing yet more proof of the link between the two.

The Vital Role of Veterinarians in the Future of Dairy Farming

Thu, 27 Jun 2024 13:57:15 GMT

This article was written by Maggie Cronk, a 2027 Iowa State University Doctor of Veterinary Medicine Candidate. In addition, she is serving as the 2024 Iowa Dairy Ambassador.

As a dairy ambassador, veterinary student, and daughter of dairy farmers, I care deeply about the future of the dairy community. Veterinarians are vital to a dairy farm’s success, but there are still dairy producers who see them as an additional cost rather than a valued asset. As the dairy community is continually adapting to the ever-changing world, so is veterinary medicine.

The Evolving Role
Traditionally, dairies call veterinarians primarily for essential procedures like pregnancy checks or to save a sick cow. However, the role of veterinarians in dairy farming is expanding far beyond just these emergency interventions. Today, veterinarians play a crucial role in helping farms identify areas of opportunity, leading to more profitable and sustainable operations.

For example, a veterinarian may notice an issue with the sand bedding being too wet, which could lead to increased cases of mastitis and a decrease in overall milk production. Addressing these seemingly minor issues can yield significant improvements on an already successful farm.

Leaning into Technology
Based on the recent Farm Journal State of the Dairy Industry Report, more than 50% of farmers either currently utilize or plan to implement technology that can record rumination, activity and other health parameters within the next few years. This data, while immensely valuable, can be overwhelming for farmers who are already stretched thin with their daily responsibilities.

Bridging the Gap with Expertise
Many farmers may not have the time to comb through all the data or may not know how to maximize an opportunity it presents. This is where trained veterinarians can also add immense value. By helping to analyze and manage this data, veterinarians can explore areas for improvement and underscore current successes.

A Community Effort for Future Stability
In these trying times, where labor and other input costs are increasing while milk prices remain stagnant, finding every way to be profitable is essential. It’s clear that to maintain and enhance the way of life as dairy farmers, the community must lean on each other and the professionals around them, so farms can thrive, prosper and prepare for the next generation to continue the legacy.

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Liver Biopsies Could Replace “Bugs and Drugs” Approach

Wed, 05 Oct 2022 18:44:12 GMT

What was once a relatively invasive and tedious procedure has become a potentially standard method of monitoring the health and nutritional status of dairy cows.

A liver biopsy extracts a tiny sample of a cow’s liver tissue, which can be evaluated for levels of trace minerals like zinc, selenium, copper, and manganese. Liver biopsies as a nutritional monitoring tool were discussed at length on a recent Dairy Cattle Reproduction Council webinar by Dr. Craig Louder, Technical Service Veterinarian for Axiota Animal Health.

“When cows aren’t doing well, I think we too often take a ‘bugs and drugs’ diagnostic approach – ‘What bug does she have and what drug can I use to fix it?’” Louder noted. “By proactively monitoring liver status, we can solve health problems at a more fundamental level, and pre-empt some of them from occurring at all.”

Louder said if liver biopsies show trace mineral levels that fall out of an anticipated range, those minerals may need to be adjusted via ration changes and/or supplementation to support transition-cow health, reproductive cyclicity, uterine health, embryo viability, and calf vitality.

That helpful information once was rather challenging to capture, but the process has recently changed for the better. “We used to do liver biopsies with an instrument called a ‘punch biopsy,’” Louder explained. “It was fairly invasive and took a sample from the liver using a tool about the size of an ink pen. It sometimes led to bleeding, clostridial disease, and peritonitis, and it scared a lot of people off.”

Now the process is safer and simpler with an instrument called the “Tru-Cut.” A Michigan State University veterinary bulletin said liver samples can be extracted via the Tru-Cut method “quickly, conveniently, and with little or no risk to the animal.”

Louder said the liver tissue sampled in this manner is about ½-inch long and the width of a piece of mechanical pencil lead. The 14-gauge needle used to extract it is the same size that would deliver IV calcium for a case of milk fever, only longer.

“It’s a 6-inch needle, and we make a small incision on the right side of the cow, between the 10th and 11thribs,” Louder explained. “We insert the needle through the muscle wall and withdraw about 10-15 mg of tissue from the liver.” The Michigan State authors noted some evaluations require 20 mg of tissue, so two samples may be required.

According to Louder, hepatic trace mineral levels in adult dairy cows are not static. They wax and wane through the pregnancy cycle, and will be lowest at the time of calving, when the dam has transferred a good share of her reserve to her fetus via the bloodstream. Levels then will rebuild in the liver with the next pregnancy, reaching their peak at about 6-7 months gestation.

“The timing of the sample is not as important as knowing the stage of pregnancy at which it was taken,” explained Louder. “If we’re having a high incidence of ketosis, metritis, or retained placentas, there would be great value in screening 10-12 fresh cows and checking their levels. Dry-off is another excellent time to check because those cows will have been on the lactating herd ration for a long time. But the expected levels will vary at those two sampling points.”

He also noted the merits of taking liver biopsies of calves to check their trace mineral status -- as either an ongoing monitoring metric, or a diagnostic tool during health challenges such as a pneumonia outbreak.

Liver biopsies are widely used in New Zealand for dairy animal monitoring, and Louder would like to see the practice expanded in the U.S. In a poll taken during the webinar, about 75% of the audience had never had a liver biopsy performed on their animals.

“I think they has a lot of potential for proactive health monitoring in dairy animals,” he stated. “The more we know what’s going on physiologically in the herd, the more we can help those cows and their calves maximize their potential.”

For more on herd health, read:

National DHIA Seeks Veterinary Student Scholarship Applicants

Wed, 11 Nov 2020 02:12:15 GMT

National Dairy Herd Information Association (DHIA) is providing $1,500 scholarships to third-year or fourth-year college of veterinary medicine students. Applicants must be enrolled at a college that is accredited by the American Veterinary Medical Association Council on Education.

Judges will evaluate applicants based on overall interest as a veterinarian planning to work in dairy, involvement in dairy medicine and extra-curricular activities, and interest in using dairy software and dairy records to aid in dairy management and in improving animal health.

To apply for a National DHIA Scholarship for Veterinary Students, applicants must submit a letter of application and two reference letters. The letter of application requires applicants to submit information regarding their area of interest/specialty, academic background, experience using DHIA data, career plans, issues challenging dairy veterinary medicine and solutions to address those challenges. For more information, contact Elizabeth “Liz” Straw, National DHIA scholarship chair, at efarrow@purdue.edu.

Specific application requirements are posted on the National DHIA website. Applications are due Dec. 31, 2020. Recipients will be announced at the 2021 National DHIA Annual Meeting, being held in March.

National Dairy Herd Information Association, a trade association for the dairy records industry, serves the best interests of its members and the dairy industry by maintaining the integrity of dairy records and advancing dairy information systems.