Effect of supplementation of rumen protected choline and methionine on milk yield and composition of early lactating dairy cows
Neelima Jayaraj, Sajith Purushothaman, K. Ally, Deepa Ananth and Shibu Simon
An experiment was conducted on early lactating dairy cows to study the effect of rumen protected choline (RPC) and methionine (RPM) on milk yield and composition. Fifteen crossbred dairy cows in early lactation (within 10 days of calving) were selected and randomly allotted to any one of the following three dietary treatments, T1 (Control)- with compound feed mixture containing CP- 20% and TDN- 68% , T2- T1+20g RPM and 20g RPC, T3- with compound fed mixture containing CP- 17%, TDN- 68% + 20g RPM and 20g RPC. All the experimental animals were fed as per ICAR feeding standards (ICAR, 2013). Results revealed no significant difference (p>0.05) in milk yield and 4 per cent fat corrected milk (FCM) yield between the three treatment groups. Among the milk constituents, animals in T3 had significantly higher milk fat (p<0.05), SNF (p<0.05), protein (p<0.05) and total solids (p<0.01) compared to those in T1 and T2. Milk urea nitrogen levels did not differ significantly among the three treatments and were within the normal range. The study showed that milk composition could be effectively improved by supplementing feed with rumen protected forms of choline and methionine in combination at lower dietary protein level without any reduction in milk yield.
Key words: Rumen protected choline, rumen protected methionine, early lactating dairy cows