Indian Journal of Animal Nutrition

The present experiment was conducted to evaluate the effect of supplementing rumen protected choline (RPC) on milk yield, composition and milk choline content of crossbred cows. Twenty five crossbred cows (Bos taurus × Bos indicus) were selected on the basis of most probable production ability (MPPA; 4116 kg) and lactation number (2^nd to 4^th). The cows were divided into 5 groups of five animals each. Animals in control group (T₁) were fed chopped wheat straw (particle size: 1.5–2.0 cm), chaffed green maize fodder (particle size: 2.0–2.5 cm) and concentrate mixture as per requirements (NRC, 2001). Animals in second group (T₂) were fed with 54 g RPC (10 g intestinally deliverable), third group (T₃) with 81 g RPC (15 g intestinally deliverable), fourth group (T₄) with 108 g RPC (20 g intestinally deliverable), and fifth group (T₅) with 135 g RPC (25 g intestinally deliverable) per cow per day along with basal diet as fed to group T₁. The actual duration of the experiment was 7 days after an adaptation period of 21 days. It was observed that commercial RPC product contained 25.44% choline. The rumen escape potential (REP) of the product was 72.89% with effective degradability of 27.11%. Choline supplementation had no effect on milk yield and composition, however, milk choline content was higher (P<0.05) in RPC supplemented groups as compared to that of group T₁ but the level of RPC did not have any significant effect on milk choline content. Thus, the lowest dose of 54 g RPC/cow/d was considered best for feeding to animals because beyond that level there was no additional benefit in terms of increase in milk choline content in crossbred cows.