This year we blood tested over 100 calves to test their antibody levels and see their range of passive transfer. The results were quite mixed, the majority were very good however, there were a few that were surprisingly lower.
Calves are born without their own immune system which does not kick in until 2-4 weeks of age. They rely entirely on the passive transfer of antibodies via good quality colostrum to fight infections, illness, and disease in the first few weeks of life. Failure of passive transfer can cost plenty in treatments for ill calves, they have a much higher likelihood of dying and their growth rates will be lower.
Here are some of the results from a few of the farms we tested, the lowest individual result we had was 2.6 and there were plenty on the 3-4 scale. Anything less than 4.7 is considered a failure of passive transfer. These levels are affected by colostrum management. Quickly; Quantity; and Quality are the ‘3 Q’s’ of good colostrum management.
>5.2 indicates good antibody levels
4.7 to 5.2 indicates marginal antibody levels
<4.7 indicates poor antibody levels or failure of passive transfer