The aim of this study was to investigate the effects of dietary rumen-protected choline (RPC) on the live weight and body condition score (BCS) of dairy cows during the transition period. A total of 30 Holstein dairy cows were allotted to one control group and two experimental groups (10 animals per group) that were fed different diets from 3 weeks prior to the expected calving date until 21 days postpartum, namely, 1) control group: basic diet; 2) treatment Group 1: basic diet supplemented with 60 g/animal/day of RPC; and 3) treatment Group 2: basic diet supplemented with 120 g/ animal /day of RPC.
The mean body weights of the control group and treatment Groups 1 and 2 at parturition were 593.17 kg ± 29.211b, 672.060 kg ± 23.744a and 584.86 kg ± 25.300b, respectively. The differences between the groups in terms of weekly mean live weight were significant at parturition (P=0.0124), whereas they were not significant in the weeks post-partum. The time-dependent changes for intragroup x group interactions were also not significant for live weight (P>0.05). The mean body condition scores of the control group and treatment Groups 1 and 2 at the end of the research period were 2.58±0.163, 2.90±0.158 and 2.79±0.125, respectively (P>0.05). Rumen protected choline supplementation did not have a significant effect on the BCS of dairy cows during the transition period. Therefore, RPC is not required when proper rumen fermentation is occurring and isocaloric and isonitrogenous rations are provided. However, in order to better understand the effects of RPC on dairy cows during the transition period, there is a need for further studies on animals with known metabolic profiles, malnourished animals, those producing high milk yields and those with metabolic disorders.
Transition period, Rumen-protected choline, Dairy cow, Body condition score