†National Dairy Research Institute, Bangalore-560 030.
College of Veterinary and Animal Sciences, Mannuthy, Trichur-680651 (India)
*Part of the research work ccaried out ffo rte eequirement of Ph.D. degree eourse of Kerala agricultural University, Mannuthy, Trrchur by the first author.
In situ dry matter and protein disappearance of groundnut cake, gingelly cake, rubber seed cake and coconut cake in the rumen of cattle were studied by nylon bag technique. Groundnut cake, gingelly cake and rubber seed cake were highly susceptible to rumen microbial degradation but coconut cake was more resistant. The protein disappearance data were used to derive the constants ‘a’, ‘b’ and ‘c’ of the exponential equation p—a+b (1—e-ct). The rate of degradation was then linked to the outflow rate from the rumen (k) to arrive at the effective protein degradability (P) using the formula p=a+bc/c+k. The effective protein degradability of each cake was calculated over a range of rumen outflow rates varying from 0.01 to 0.10/h. The effective protein degradability of groundnut cake, gingelly cake, rubber seed cake and coconut cake at an outflow rate of 0.05/h was 66.76, 85.12, 68.61 and 19.09 per cent respectively. The coconut cake was a good source of bypass protein for ruminants.
