The effect of kefir by-product supplemented to whole milk during the suckling period on the growth and health parameters of holstein calves

The effects of the orally administered kefir by-product on the growth and health parameters of Holstein calves during the suckling period were investigated. In the study, 21 Holstein calves were used, and the calves were divided to the groups by considering their live weight averages. The calves were given 4 L/day whole milk as two meals (2 L in the morning-2 L in the evening). Kefir by-product was supplemented to the experimental groups as 0, 20 and 40 mL/d/calf and commercial feed additive was supplemented to milk as 15 g/d/calf. The calves were4 weaned when they consumed 800 g/d of starter for three consecutive days. The calves were given starter ad libitum, and alfalfa hay was given after the weaning. The results obtained in the study showed that the kefir by-product significantly increased the total and daily live weight gains of the calves and improved their growth performance. However, there was no significant effect on the weaning age of calves. 20 mL/d kefir by-product significantly increased the total and daily feed consumption of the calves and significantly improved the feed conversion ratio. Kefir by-product affected the calves' pulse and respiratory rate, respiratory score, rectal temperature, general appearance, the number of illness days, fecal score and the number of days with diarrhea insignificantly. The concentration of immune and antioxidant markers of calves increased insignificantly with the supplementation of kefir by-product, and the concentration of oxidant markers decreased insignificantly. As a result of the current study, it is thought that the kefir by-product has the potential to be used in the healthy calf rearing, but it will be useful to clearly demonstrate the potential by studying in different environmental conditions and at different doses.