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Pneumonia, or bovine respiratory disease (BRD), accounts for more than 24% of preweaned heifer deaths and 58.9% of weaned heifer deaths on U.S. dairies, but there are ways to boost calf immunity and fight back against BRD.1

“Producers are starting to really dig into calf health, from the time they are in utero until they are bred,” said Linda Tikofsky, DVM, Boehringer Ingelheim. “They’re raising stronger calves that are more resilient to BRD.”

Building immunity from the start

Colostrum is the first step to getting calves started on the right hoof. “Calves should receive high-quality colostrum within one to two hours of birth,” stressed Dr. Tikofsky. “We recommend feeding 10 to 12% of the calf’s body weight in colostrum in that first feeding.”

This initial colostrum provides calves with antibodies that fight against the most common viral and bacterial infections found within their environment, since calves are born with minimal natural immunity. However, not all colostrum is created equal.

“Producers can take action to ensure high-quality colostrum is being produced for calves, starting with the health of the mother,” explained Dr. Tikofsky. “Vaccinating the dam at the correct time, maintaining a 45- to 60-day dry period, and collecting colostrum immediately after the calf is born will help ensure that we are providing the best passive immunity to the calf.”

Producers can also set up a colostrum testing procedure to monitor the quality of the colostrum dams are producing. Colostrum can be evaluated by using on-farm measurement tools such as a colostrometer or refractometer. The ideal level to aim for is an immunoglobulin (IgG) concentration higher than 50 g/L or 22%.2 “But don’t discard colostrum that tests less than 22%,” recommended Dr. Tikofsky. “Lesser quality colostrum can be used as a second or third feeding and provide that calf with more nutrients and additional bioactive factors to enhance immunity and growth.”3

Follow up with effective vaccines

As passive immunity from colostrum begins to wane, vaccinating calves against BRD is the next step in ensuring the health of your future herd. For best results, calves should receive vaccines at least two weeks in advance of high-stress events such as weaning or commingling in group housing.

“A comprehensive injectable modified-live virus vaccine that induces both local and systemic immunity is the best choice for producers to stimulate calves’ acquired immunity,” emphasized Dr. Tikofsky.

Local immunity (IgA antibodies) provides protection on the mucosal surface of the respiratory tract, where pathogens initially enter the calf’s body. Meanwhile, systemic immunity (IgG antibodies) is critical for building long-term protection, as those antibodies circulate in the bloodstream. A vaccine stimulating multiple types of immunity gives calves comprehensive BRD protection.

Dr. Tikofsky recommends that producers consult their local veterinarian and nutritionist. These experts can identify and implement strategic protocols to protect the health of cows and their calves.


1 USDA 2018. APHIS, Veterinary Services, NAHMS. Health and management practices on US dairy operations, 2014. February 2018. Available at: Accessed May 15, 2023.

2 Godden SM, Lombard JE, Woolums AR. Colostrum management for dairy calves. Vet Clin North Am Food Anim Pract 2019;35(3):535–556.

3 van Soest B. et al. Short communication: Effects of transition milk and milk replacer supplemented with colostrum replacer on growth and health of dairy calves. J Dairy Sci 103: 12104-12108.

About Boehringer Ingelheim Animal Health USA

Boehringer Ingelheim Animal Health is working on first-in-class innovation for the prediction, prevention, and treatment of diseases in animals. For veterinarians, pet owners, producers, and governments in more than 150 countries, we offer a large and innovative portfolio of products and services to improve the health and well-being of companion animals and livestock.

As a global leader in the animal health industry and as part of the family-owned Boehringer Ingelheim, we take a long-term perspective. The lives of animals and humans are interconnected in deep and complex ways. We know that when animals are healthy, humans are healthier too. By using the synergies between our Animal Health and Human Pharma businesses and by delivering value through innovation, we enhance the health and well-being of both.

Boehringer Ingelheim Animal Health has deep roots in the U.S. From a start in St. Joseph, Missouri, more than 100 years ago, it has grown to encompass seven sites. Boehringer Ingelheim Animal Health’s portfolio contains widely used and well-respected vaccines, parasite-control products and therapeutics for pets, horses and livestock.

Learn more about Boehringer Ingelheim Animal Health USA at