Get the best ROI from calf vaccination

By Dr. Jonathan Townsend

Vaccination helps boost calves’ immune systems and prevent infectious diseases. However, selecting the right vaccine can be complicated — intranasal vs. injectable, bacterial vs. viral, live vs. killed, and other considerations. There’s also timing, boosters, handling and additional factors that affect immunization success.

Understanding the fundamentals of vaccination helps optimize the return on your vaccine investments and ensure calves are prepared for the challenges they’ll face.

Vaccination is the act of administering a vaccine. Immunization is achieving the desired immunological response. But a vaccine cannot do the job alone. Getting the best results from your vaccination program starts with healthy calves. To optimize vaccine effectiveness and return on investment (ROI), provide calves with a strong nutritional foundation and maintain clean and stress-free environments.

A calf looks through cattle equipment.

Nutrition: Prioritize colostrum

A solid nutritional foundation from birth is essential for the proper development of a calf’s immune system. High quality colostrum intake is crucial for passive transfer of antibodies to the calf. Failure of passive transfer reduces long-term performance in dairy cattle, including delayed time to first calving, decreased average daily gain, and decreased milk and fat production at first lactation.1-3

The quantity, quality and timeliness of colostrum consumption are what matter most.

Quantity: Depending on size, most large-breed calves should receive three to four quarts of good-quality colostrum (or 10% to 12% of birth weight for smaller calves) as soon as possible after birth. Give an additional two quarts (or 5% of birth weight) at a second feeding, within six to eight hours after the first feeding.

Quality: Colostrum is richer in nutrients than whole milk — it is higher in energy and vitamins, contains twice as much dry matter and minerals, and has five times as much protein.4 Plus, the colostrum has lower lactose content, reducing the incidence of diarrhea. If high quality colostrum is not available, only use products designed to replace colostrum. These contain more immunoglobulin and provide more antibodies than poor or moderate quality colostrum.

To boost colostrum quality, administer a scours vaccine like BOVILIS® GUARDIAN® to the dam during the dry period, which helps increase antibodies in colostrum to protect calves against scours.

Quickness: In the first few hours after birth, maternal antibodies (primarily IgG) in colostrum are absorbed into the bloodstream and IgG is slowly resecreted into intestines and lungs. IgG absorption declines rapidly after birth. To meet the passive transfer goal of greater than 10 mg/mL of IgG, calves should receive sufficient colostrum within six hours of birth to bolster their immune defenses.5

The Dairy Calf and Heifer Association publishes its “gold standards” for growing efficient, healthy and profitable animals. According to these benchmarks, the target growth rate for calves is 1.7-2 lbs. average daily gain (ADG).6 Use this as a guide for monitoring the success of your calf nutrition. Keep in mind that nutritional needs of beef x dairy crossbred calves have genetic potential for higher rates of gain and should be fed accordingly.

For all calves, introduce starter feed to encourage early rumen development and provide clean, fresh water for hydration and overall health.

Facilities: Minimize stress and disease exposure

Stress can prevent calves from building an optimal immune response to vaccination, making them more susceptible to infections. A stress-free environment is vital for successful immunization.

Airflow: Ensure good air circulation in calf housing to reduce the concentration of airborne pathogens, incorporating both natural ventilation and positive pressure ventilation.

Spacing: House calves individually or in small groups to help prevent disease spread, providing approximately 30 square feet or more of bedded space per calf, not including service alleys.

Comfort and cleanliness: Ensure pens have drainage underneath, with plenty of bedding in cool weather (50 F or less). Maintain clean and hygienic calf pens, equipment, feeding areas and surfaces.

Vaccination: Tailor to specific needs

Different herds may face varying disease challenges, so it pays to customize your vaccination program based on the specific needs of your farm — your veterinarian can help with this. A successful vaccination program must be effective in producing an immunological response and also efficient in improving clinical health and performance.

Core vaccines protect against common and severe diseases that can pose significant threats to calf health. Examples include vaccines for clostridial diseases, bovine respiratory syncytial virus (BRSV), bovine viral diarrhea virus (BVDV) and infectious bovine rhinotracheitis (IBR). Additional vaccines may be necessary based on regional disease prevalence and individual farm circumstances, such as diseases like salmonellosis, rotavirus or coronavirus.

Intranasal vaccines are not affected by maternal antibody interference, which may impede certain injectable vaccines from inducing an immune response.7,8 Other benefits of intranasal vaccines include:

  • No risk of injection site reactions — easier on the calf.
  • Less likely to induce systemic inflammation compared to injectable vaccines.9
  • Reduces effects of bacterial endotoxins contained in injectable Mannheimia haemolytica and Pasturella multocida vaccines.10
  • Initiates a relatively rapid immune response.11

BOVILIS® NASALGEN® 3-PMH is the first and only intranasal BRD vaccine offering protection against IBR, BRSV, PI3, Pasteurella multocida and Mannheimia haemolytica. It’s safe to use in calves one week of age and older for a strong, healthy foundation. And a unique BluShadow® diluent means there’s no second-guessing which animals have been vaccinated.

Vaccines must be handled, stored, mixed and administered correctly to be effective. Use vaccines that have been stored out of sunlight, at the proper temperature and within their expiration dates.

Work closely with your veterinarian to develop a vaccination strategy that best suits the unique requirements of your farm.


  1. Waltner-Toews D, Martin SW, Meek AH. The effect of early calfhood health status on survivorship and age at first calving. Can. J. Vet. Res. 1986;50(3):314-317.
  2. Robison JD, Stott GH, DeNise SK. Effects of passive immunity on growth and survival in the dairy heifer. J. Dairy Sci. 1988;71(5):1283-1287. doi:10.3168/jds.S0022-0302(88)79684-8. Retrieved Aug. 8, 2023.
  3. DeNise SK, Robison JD, Stott GH, Armstrong DV. Effects of passive immunity on subsequent production in dairy heifers. J. Dairy Sci. 1989;72(2):552-554. doi:10.3168/jds.S0022-0302(89)79140-2. Retrieved Aug. 8, 2023.
  4. Davis CL, Drackley JK. The Development, Nutrition, and Management of the Young Calf. Iowa State University Press. 1998.
  5. Modified from: The Compendium 15:335, 1993.
  6. Dairy Calf and Heifer Association. Gold Standards. Third Edition. Setting the benchmarks for your herd’s future. Production Standards. 9-12. Retrieved Aug. 8, 2023.
  7. Osman, R., Malmuthuge, N., Gonzalez-Cano, P., Griebel, P. Development and Function of the Mucosal Immune System in the Upper Respiratory Tract of Neonatal Calves. Annual Review of Animal Biosciences. 2018.
  8. Merck Animal Health Study MS-N3PMH-3-19: Efficacy of vaccination in colostrum fed 7-day old calves when using multivalent intranasal vaccine in the face of maternal antibody.
  9. Engelken, T. J., Roth, J. A., Renter, D. G., Meyer, B. D., Burdett, W. W., Hill, K. L. The Effect of respiratory vaccine components and route of delivery on weight gain and inflammatory response in suckling beef calves. Bovine Prac. 2016. 50(2), 165-174.
  10. Spire, M. (2014). Vista®: Endotoxin Load. Merck Animal Health Technical Bulletin.
  11. Kesl, L., Saltsman, R., Burdett, B., Nordstrom, S., Xue, W. Determination of the Number of Days from Vaccination to Challenge Required for Protection from Infectious Bovine Rhinotracheitis (IBR) Virus Challenge Following Vaccination with Onset 5 IN and Vista 5 SQ in 13–30 Day Old Colostrum Deprived Calves. Publication pending. World Buiatrics. 2022.

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About the author

Dr. Jonathan Townsend

Jonathan Townsend

D.V.M., Ph.D.,
Dairy Technical Services,
Merck Animal Health