Investigation on the Effect of Supplementing Rumen-Protected Forms of Methionine and Choline on Health Situation and Reproductive Performance of Holstein Dairy Cows

Abstract

Twenty Holstein dairy cows in their first and second lactation were used from 4-week prepartum through 20-week postpartum. The aim was to investigate the effect of feeding different levels of ruminally protected methionine and choline on health situation and reproductive indices of Holstein dairy cows. Cows were randomly assigned to receive one of the following treatments: 18 g day(-1) of rumen protected methionine (RPM), 60 g day(-1) of rumen protected choline (RPC), 18 g day(-1) of RPM + 60 g day(-1) of RPC and neither supplement (control). The treatments significantly affected services per conception and open days of lactating dairy cows, but did not significantly affect on days to first estrus and number of pregnant cows. RPM + RPC-fed cows had the lowest open days, days to first estrus and services per conception compared with other groups. Although no statistical differences were noted for any given health category, the overall incidence of health-related disorders was numerically lowest for cows fed RPM + RPC. Results indicate that the supplementation of RPM and RPC have been improved reproductive performance and health situation of dairy cows.