Calfhood Vaccination

Winter Herd Health: Optimizing Cow-Calf Vaccination for Spring Success

Wed, 07 Jan 2026 17:12:31 GMT

Winter often brings renewed focus on vaccination — not because disease risk suddenly appears, but because management decisions make it more visible. Calving preparations, breeding plans, housing changes and closer observation of cattle prompt producers to ask a familiar question: Are we covered on vaccines?

It’s a reasonable place to start, but not where effective planning ends. Vaccines are a critical part of herd health, yet their success depends on how well they align with animal condition, management practices and disease risk. On a recent episode of “ Cattlemen and Veterinarians ,” Dr. Jason Banta of Texas A&M spoke on the opportunity for veterinarians to reframe vaccination as strategy, not just product choice.

The Role of Vaccination in Herd Health Programs

“The vaccine protocol is going to vary a little bit depending on the risk level of the operation and where you’re located, but I do think there are some core vaccines that all cow-calf producers probably need to think about including in their operations,” Banta says.

These include clostridial vaccines that protect against pathogens that persist in the environment and viral respiratory vaccines that play a key role in reducing clinical disease, reproductive loss and downstream performance impacts.

“Spores from those clostridial organisms are in the environment, and so our animals are typically always exposed to that,” Banta says. “When we think about clostridial vaccines, we’ll see either a seven way clostridial vaccine, an eight way clostridial vaccine or a nine way clostridial vaccine. It’s important to read the label to see exactly what’s in there.”

Usually, the difference between a seven- and eight-way vaccine is coverage for Clostridium hemolyticum, which causes redwater disease. The nine-way vaccine often includes tetanus, which may or may not be relevant to an operation.

Banta also emphasizes the importance of vaccinating the cows along with the calves, as antibodies can be passed on in the colostrum. This is especially important when it comes to infectious bovine rhinotracheitis and bovine viral diarrhea as these can cause reproductive losses.

Geographic Threats are Important for Herd Vaccine Plans

“One that we deal with in my area is lepto, so that’s a routine pathogen that we vaccinate for,” Banta says. “It’s important because it causes reproductive losses in the cow herd, but it can also cause the death of younger calves.”

Above all, Banta encourages open discourse between producer and veterinarian to discuss which vaccines are most relevant to their operation, noting that these could change over time.

“As a minimum, I would think about the clustered organisms and then the viral respiratory organisms, and then if you need lepto or anything else, that would be a herd specific situation,” Banta says.

Vaccine recommendations are most effective when matched to the conditions cattle will face, not simply the diseases producers want to avoid.

Immune response is reduced in cattle experiencing nutritional deficiencies, stress or concurrent disease. Winter conditions — changes in forage quality, weather stress and closer confinement — can amplify those challenges.

Strategic Planning for Spring Herd Health

As winter management transitions into spring preparations, the goal shifts from maintaining the status quo to building a foundation for the upcoming production cycle. While Banta’s advice provides a technical road map of core versus situational vaccines, the true value lies in timing and execution. Winter provides a window for producers and veterinarians to conduct a herd health audit together.

To ensure your vaccination strategy is effective, consider these key pillars of a winter health audit:

Assess nutritional status: Verify that cattle have the energy and mineral reserves necessary to mount a robust immune response.
Review regional risks: Discuss whether local pressures require specific additions to the core protocol.
Evaluate management stress: Identify environmental challenges or handling practices that could compromise the efficacy of the health program.
Audit records and timing: Review previous disease challenges to ensure the timing of vaccine protocols align with the herd’s peak periods of risk.

Ultimately, a general vaccination schedule is a starting point, but a strategic plan is a competitive advantage. By focusing on the why and the when during the winter months, you ensure the investment in animal health yields the highest possible return when the spring calving season arrives.

Managing Endotoxin Load in Cattle Vaccination Programs

Wed, 21 Jan 2026 17:14:13 GMT

Calves that look rough the day after processing are a familiar sight in both cow-calf and feedlot systems. While infection, handling stress and weather are often blamed, another contributor is increasingly part of veterinary conversations: endotoxin load associated with vaccination.

“Think about if you got the stomach flu and you’re sitting on the couch all day and you just don’t feel good. Same thing with these calves,” says Dr. Jeremi Wurtz, beef cattle technical consultant for Elanco Animal Health, when describing vaccine sweat from endotoxin stacking.

Endotoxin exposure is neither new nor is it inherently harmful. The challenge arises when cumulative exposure overwhelms an animal’s ability to respond appropriately. Understanding how endotoxin stacking occurs and how vaccine design influences that risk gives veterinarians another tool to fine-tune herd health programs.

Why does Endotoxin Load Matter?

Endotoxins, primarily lipopolysaccharides (LPS), are components of the outer membrane and cell wall of gram-negative bacteria. These can make their way into an animal’s system through natural pathogen exposure or through vaccination with killed gram-negative bacterial vaccines.

The concern is not exposure itself, but the cumulative physiologic response when multiple sources are introduced close together.

“Say we vaccinate a calf with a Mannheimia haemolytica vaccine, and then we also vaccinate that same calf with a somnus vaccine, and then we give him a Moraxella vaccine,” Wurtz says. “Sometimes there will be multiple different isolates in those vaccines, and so you’re really loading up the additive effects of those endotoxins.”

When this happens, the endotoxin load can pass a threshold causing that calf to react negatively.

What Endotoxin Load Looks Like in the Field

Clinically, endotoxin reactions can resemble early respiratory disease. Affected calves might be off feed, lethargic and slow to recover after vaccination. Timing is one of the most useful clues: Endotoxin-related responses typically appear about 24 hours post-vaccination.

“It’s usually the next day,” says Wurtz, noting the events surrounding vaccination also influence calf response. “The stress of handling those calves through the chute, maybe going from one pen to another, maybe there was a shipping event, these stressors can cause calves to have more sensitivity to endotoxins.”

The overlap in presentation with other ailments explains why endotoxin effects can go unrecognized or be attributed solely to handling or disease pressure.

Endotoxin Stacking

Endotoxin stacking most often occurs when multiple gram-negative vaccines are administered at the same time. Each product contributes its own endotoxin load and the effects are additive.

“If one vaccine has 80,000 endotoxin units, and the other has another 80,000, and another 80,000, all of a sudden you are now going to really push that calf into a susceptible state,” Wurtz says. “Any time we can minimize the stacking or loading of endotoxins is pretty important.”

In practice, spacing vaccines is not always feasible. Labor, chute time and cattle flow frequently dictate protocol designs, making vaccine selection an important variable.

Is there a Magic Number for Endotoxin Load?

There is no single endotoxin threshold that predicts clinical response.

“To say ‘oh, you have to be under 180,000 endotoxin units’ is not a real proper thing to say because it’s relative,” Wurtz says. “A 900-lb. yearling calf is going to be more tolerant to endotoxin loads than a 300-lb. calf that just got weaned.”

This variability underscores why endotoxin management is best viewed as risk reduction rather than strict compliance. Along with stress, immune and nutritional status also play a role on the endotoxin load a calf can handle.

Vaccine Handling Mistakes can Increase Endotoxins

Vaccine handling plays a critical role in endotoxin release. Freezing, thawing and aggressive agitation can damage cellular components, increasing the amount of free endotoxin delivered at injection.

“A lot of times a vaccine will say shake before using. That doesn’t mean to take it and shake it like crazy, because that can damage the antigens in there and release a lot more free endotoxin as well,” Wurtz advises. “You want to just lightly turn and rotate those vaccines so you don’t overagitate and damage those antigens.”

Proper refrigeration and storage is also important for optimizing antigen delivery by avoiding damage and minimizing free endotoxins within the vaccine.

How Low-Endotoxin Vaccines are Designed

Low-endotoxin vaccines aim to reduce exposure by limiting unnecessary bacterial components. Recombinant and subunit approaches use only the specific antigen required to stimulate immunity, avoiding much of the LPS contained in whole-cell vaccines.

The Nuplura PH and Nuplura PH+5 vaccines from Elanco are examples of these low-endotoxin vaccines. They use recombinant technology to produce and isolate leukotoxin proteins for vaccine incorporation instead of including the whole bacterial cell.

“Any time you have a full cell or cellular components in a vaccine, you’re going to have the risk of having additional endotoxin,” Wurtz says.

Practical Takeaways

Low-endotoxin vaccines are not a replacement for sound herd health planning. They are one component of risk management, alongside careful product selection, realistic stacking decisions and proper handling.

“There’s no magic number to be under for endotoxin load, but anytime we can lower it is a good opportunity,” Wurtz says.

By matching vaccine design to calf risk, veterinarians can reduce unnecessary inflammatory stress while preserving protective immunity, especially when conditions are less than ideal.

Managing Disease Risk Before It Arrives

Wed, 24 Dec 2025 14:33:17 GMT

As cattle move more frequently across regions and production systems, veterinarians are increasingly tasked with helping clients prevent the introduction of infectious disease that can persist silently and erode herd performance over time. In many cases, the greatest risk is not an outbreak, but the gradual establishment of a pathogen that is difficult or impossible to eliminate once introduced.

While biosecurity includes people, equipment and environmental considerations, animal movement remains the most important driver of infectious disease risk. This was the central topic of discussion on a recent episode of Dr. Dan Thomson’s “DocTalk.”

Why Animal Movement Drives Disease Risk

“Our biggest risk is going to come from the animal itself,” said Dr. Dustin Loy, director of the Veterinary Diagnostic Center at the University of Nebraska-Lincoln. “This is going to be something that’s going to move with the animal and be transmitted from that animal to the rest of the herd.”

Transport and commingling represent peak risk periods for disease transmission. The stressors associated with hauling, dietary change and social disruption can suppress immune function and allow latent or subclinical infections to emerge. When cattle with different exposure histories mix, pathogens can spread rapidly through immunologically naive groups.

“If we can make sure that those animals we’re sourcing have a herd health program, they’ve had those calfhood vaccines and the boosters, that they have a high level of immunity to the common diseases, that’s going to really help us prevent some amount of problems,” Loy says.

However, while vaccination programs reduce risk, they are insufficient for a number of diseases of biosecurity concern. Performing diagnostic testing before animals are purchased or moved can help identify infected animals before they enter herds.

Diseases That Define Biosecurity Risk

Several diseases are consistently central to cattle biosecurity planning due to their transition dynamics, diagnostic challenges, and long-term herd impact.

Johne’s Disease

Johne’s disease remains one of the most difficult infections to control as clinical signs don’t appear until years after the animal has been infected.

“The challenge with Johne’s is that those calves are infected when they’re a month or less in age,” Loy says. “We’re not able to test those calves until they’re at least a year and a half, and usually we want to wait until they’re two or three years old just to know if they’re infected. And so that’s a real diagnostic challenge: being able to identify those animals early.”

Due to this prolonged subclinical phase, infected animals can shed Mycobacterium avium subspecies paratuberculosis, contaminating the environment and exposing young calves. Clinical signs include progressive weight loss, decreased production and chronic diarrhea, with no effective treatment. Because diagnostic sensitivity improves with age, Loy says fecal testing at pregnancy checks provides a practical surveillance point for identifying infected adults and limiting further transmission.

Anaplasmosis

Anaplasmosis is increasingly detected outside historically endemic regions, likely due to cattle movement. Caused by Anaplasma marginale, this disease is transmitted mechanically by ticks, biting flies and contaminated instruments. Calves exposed early often develop immunity with minimal clinical disease, but infection in naive cattle can cause severe anemia, abortions and sudden death.

Importantly, vectors can only transmit the organism if infected animals are present, making the testing of incoming cattle a key biosecurity step to prevent establishing a persistent reservoir within a herd.

“If we don’t have animals with anaplasmosis coming into the area, the ticks don’t transmit anaplasmosis,” Thomson says.

Bovine Viral Diarrhea (BVD)

Despite routine vaccination, BVD remains a biosecurity concern due to persistently infected (PI) animals.

“You get cows that are infected when they’re pregnant, they infect the fetus, and then the fetus does not have an immune response to the virus, so that calf is born infected. It never clears the virus and continues to shed that throughout its life,” Loy explains.

PI animals serve as powerful sources of infection, contributing to reproductive failure, immunosuppression, respiratory disease and poor performance, even in vaccinated herds. Ear-notch testing is a practical, cost-effective method for identifying PI animals prior to commingling.

Bovine Leukosis Virus (BLV)

BLV transmission occurs through blood transfer, including needles, equipment and biting insects. While many infected cattle remain asymptomatic, a subset develop lymphoma later in life, reducing longevity and productivity. Screening animals intended for long-term retention, such as breeding stock or embryo recipients, can help prevent gradual spread within expanding herds.

Core Biosecurity Questions for Veterinarians

When advising clients on cattle purchases or movements, consider asking the following questions:

Where are the animals coming from and have they been commingled with cattle from other sources?
Are these animals being moved between groups, pastures or regions with different disease exposure histories?
Do the source animals have an established herd health program, including appropriate core vaccinations and boosters?
Can diagnostic testing be used before or shortly after movement to reduce quarantine time and uncertainty?

Effective biosecurity does not eliminate all disease risk. Instead, it allows for the identification of the most consequential threats early, before they become entrenched, expensive and difficult to control.