More farmers are checking the quality of colostrum they feed to calves, with new survey findings highlighting growing awareness of the role colostrum plays in supporting calf immunity.
The survey of 142 GB dairy farmers by MSD Animal Health found that 66.2% now test colostrum quality, up from 48.8% in a comparable 2022 survey of 248 dairy farmers.
However, the findings also highlight an opportunity to strengthen monitoring of passive transfer, with the proportion of dairy farmers testing calves for failure of transfer of passive immunity (FTPI) falling from 41.1% in 2022 to 31.7% in 2026.
Dr Katie Denholm, senior university clinician in Farm Animal Clinical Sciences at the University of Glasgow, who was involved in the survey and analysis, said the findings highlight the importance of measuring both colostrum quality and the outcome in the calf.
“Testing colostrum quality is a really positive step, but it is only part of the picture. We also need to know whether calves have successfully received and absorbed enough immunoglobulin.
“Poor-quality colostrum, bacterial contamination or delayed feeding can affect absorption, so testing calves for passive transfer can help identify where management protocols may not be working as expected.”
Dr Denholm said farmers should work with their vet to routinely monitor IgG levels. “It’s a quick and relatively straightforward blood test, but it remains underutilised. It can tell farmers a great deal about whether their colostrum and calf management protocols are actually working.”
Transition milk
The survey also suggests a shift towards extended transition milk feeding, with 70.4% of dairy farmers reporting that they feed transition milk for four days or more. This compares with the 2022 survey, when 77.4% of farmers reported feeding milk replacer instead of transition milk from the third feed onwards.
This may indicate growing recognition of the benefits of extending colostrum-derived nutrients and immune factors beyond the first few feeds.
“Transition milk contains a range of bioactive components, so continuing to feed it for several days after birth can be a valuable part of a calf-rearing programme,” said Dr Denholm.
Areas for improvement
The survey also highlights opportunities to improve colostrum management.
While 82.4% of farmers now report feeding between 2.5 and 4 litres, compared with approximately 74% in 2022, the lower end of this range may not provide sufficient immunoglobulin for an average 40kg Holstein calf unless a second feed is given.
In 2002, 84% of farmers reported feeding colostrum within one hour of harvesting. In the latest survey, 66.2% reported feeding it within two hours of calving, suggesting that speed of feeding remains an important area of focus.
In addition, only 11.3% of farmers reported carrying out hygiene checks on their colostrum.
Calf rearers
The survey also highlighted the importance of colostrum management for farms buying in calves. Of the 18 farms identifying as calf rearers, five did not know about colostrum management on the farm of origin, while 14 identified poor colostrum management at the farm of origin as a risk factor for calf health.
“For bought-in calves, the first farm’s colostrum management can have consequences long after that calf has left the farm,” said Dr Denholm.
“Better communication between the farm of origin and the calf rearer around colostrum management, vaccination and disease status could therefore be extremely valuable.”
Dr Kat Baxter-Smith, veterinary advisor at MSD Animal Health, supported Dr Denholm’s point about regularly testing calves for IgG concentration, adding: “It is really encouraging to see the increase in farmers testing colostrum quality. However, the reduction in calf testing is something we should not overlook.
“Ideally, dairy farmers should be looking to monitor calf bloods regularly, ideally monthly, rather than testing just once and assuming everything is fine. IgG concentrations can be influenced by changes in farm management and risk factors, including staffing pressures and increased pressure on calf-rearing facilities during busy periods.
“Testing the colostrum tells us about the input, while testing the calf tells us about the outcome. We need both to understand whether a colostrum management programme is working effectively.”
Good colostrum management is particularly important where cows have been vaccinated to provide passive protection to their calves. Vaccines that help manage key scour pathogens in calves, such as Bovilis Rotavec Corona and Bovilis Cryptium, increase the levels of specific antibodies available in the dam’s colostrum. These antibodies are then transferred to the calf through colostrum and transition milk.
Dr Baxter-Smith added: “When farmers are investing in vaccination to help protect their calves, it is important that the management protocols are in place to allow calves to receive this antibody-rich colostrum effectively.
“Vaccination is only one part of the protection strategy. Calves need to receive sufficient antibody-rich colostrum quickly and hygienically to benefit from the passive immunity the vaccination programme is designed to provide.”
