The effects of supplementation of rumen-protected choline on some blood and milk metabolites in the transition period of dairy cattle
Özet
The aim of this study was to investigate nonesterified fatty acid (NEFA), beta-hydroxy butyric acid (BHBA), and milk urea nitrogen (MUN) profiles for dairy cows fed with rumen-protected choline (RPC) during the transition period. A total of 30 dairy cows were allocated to one control and two experimental groups (10 animals per group) and were fed from 3 weeks before calving to 21 days in milk. The control was fed only the basal diet. Treatment groups 1 and 2 were fed a basal diet containing 60 and 120 g/head/day RPC, respectively. The differences between groups were insignificant for MUN levels of colostrum and milk. There were no significant differences (P > 0.05) between the groups in terms of serum NEFA or BHBA levels. RPC supplementation did not have a significant effect on energy or protein metabolism of dairy cows during the transition period. The main effects of the periods without group effects in the model were highly significant (P < 0.01) for NEFA and BHBA. There is no need to add RPC to rations formulated as isocaloric and isonitrogenic for optimal rumen fermentation in dairy cows during the transition period. To better understand the effect of RPC on dairy cows during the transition period, there is a need for further studies of animals with known metabolic profiles, and those having high milk yields or metabolic disorders.
