Effect of feeding single-dam or pooled colostrum on maternally derived immunity in dairy calves.

Discipline: calf rearing; Keywords: survival, health, immunoglobulin, heifer, birthweight.

Colostrum management to provide adequate immunological protection to new born calves has been well investigated, and thresholds for colostrum quality, as well as optimum volume and timing for colostrum feeding have been established. However, less is known about the effect of colostrum from a single dam versus pooled colostrum from several cows on passive immunity, as well as the subsequent antibody survival in the calf. This was the topic of the study by Dr J Barry and colleagues; the aim being to assess the effect of feeding single-dam colostrum (own and other dam) or pooled colostrum on transfer of passive immunity, and also to investigate the rate of depletion of disease-specific antibodies among dairy calves. The results were published in the Journal of Dairy Science, Volume 105 of 2022, page 560 to 571. The title of the paper is: Effect of feeding single-dam or pooled colostrum on maternally derived immunity in dairy calves.

Three hundred and twenty cows and 119 heifer calves were enrolled in the study. Blood was sampled from the calves immediately after birth before they received either own-dam, other-dam, or pooled colostrum. Blood was then also sampled at 24 hours to assess serum immunoglobulin (IgG) concentration and at monthly intervals thereafter to establish disease-specific antibody survival.

The results showed that the mean colostrum IgG concentration was higher for the other-dam treatment group, whereas the own-dam and pooled treatments were similar. For all treatment groups, the mean IgG concentration was more than 80 mg per mL, which exceeds the quality threshold of 50 mg per mL. The mean calf serum IgG concentration was lower for calves fed the pooled colostrum compared with those that received colostrum from a single cow. Furthermore, there was a negative association with 24-hour serum IgG and calf birth bodyweight; calves weighing less than 30 kg at birth had the highest 24-hour serum IgG concentration. Survival of antibodies to bovine viral diarrhea, Salmonella infection, leptospirosis, bovine parainfluenza 3 virus, bovine respiratory syncytical virus, rotavirus, and coronavirus was not associated with colostrum source; however, antibodies to infectious bovine rhinotracheitis had a greater period of survival among calves fed the own-dam colostrum.

In conclusion, the results showed that feeding colostrum from a single dam (own or other dam) resulted in a higher passive immunity among calves, relative to those that received the pooled colostrum. However, it may suggest that immune exclusion occurs with pooled colostrum. Providing pooled colostrum may be a good practice as long as it can be ensured that enough antibodies are absorbed into the blood stream to deal with pathogens calves may encounter because different dams may have antibodies against different strains of viruses and bacteria, resulting in cross protection. However, this needs to be confirmed. Maternal antibody survival has been documented in this study and indicated that once calves receive a sufficient amount of high-quality colostrum, they achieve comprehensive immunity to a range of diseases. Although there were differences across treatments in terms of antibodies to respiratory viruses, which require more investigation, the study did show that respiratory diseases were associated with colostrum treatments.