Effect of a beta-carotene supplementation to dry cows on IgG concentration in the blood of calves

The reduction in the use of antibiotics through alternatives is a current topic for farmers. A beta-carotene supply to dry cows might contribute to a better calves’ health due to a higher antibodies concentration in the calves blood. This hypothesis was verified through a feeding trial with 60 dry cows on 4 different farms in Switzerland. On each farm the dry cows were divided into two groups, one control group without beta-carotene and one test group that was supplied with 600 mg beta-carotene per cow per day during at least the last 14 days of gestation. Calves were fed with colostrum of their mother within 6 hours after birth. Between 24 and 72 hours after birth IgG concentration of the calves’ blood was measured using a semi-quantitative quick test (Fassisi Bovine IgG, Fassisi, Goettingen, Germany). Blood IgG concentration was analysed using a generalized linear mixed model with binominal distribution. The probability to attain an IgG concentration in the blood higher than 10 mg/l was 65% in the control group and 93% in the test group, respectively (P=0.012). A concentration higher than 10 mg/l is described in the literature as necessary to ensure an effective immunity transfer and good health of the calves during their first weeks. We conclude that a supply of beta-carotene to dry cows might be a possibility to support calves health during their first weeks of life and therefore reduce the use of antibiotics. Further research is required to identify the optimal amount of beta-carotene supplementation to dry cows.