Effect of feeding red gram stalks based complete diets on nutrient utilization and plane of nutrition in buffaloes

Three iso-nitrogenous complete diets in a roughage concentrate ratio of 50:50 were formulated with ground red gram stalks (RGS) at 30, 40 and 50% level in complete diets and were compared with a complete diet containing 50% sorghum stover as sole conventional roughage source (control diet). These diets were evaluated in 4 adult male graded Murrah buffaloes in a 4x4 Latin square design. In each trial, the buffaloes were fed the respective diets for 30days, followed by 7 days metabolism trial and a switch over period of 10d between each trial. The RGS had 4.11% crude protein (CP), 0.64% ether extract (EE) and 60.4% crude fibre (CF). The dry matter (DM) intake by buffaloes was comparable among all the groups, indicating that the diets containing RGS up to 50% were palatable. The DM, organic matter (OM), CF (P< 0.05), neutral detergent fibre (NDF)(P< 0.05) and cellulose digestibilities in buffaloes fed diets containing up to 40% RGS was similar to those fed control diet, but further increase in proportion of RGS (50%) depressed (P< 0.01) the digestibilities. The digestibility of EE, nitrogen free extract (NFE) and hemicellulose remained comparable among all the diets. The CP digestibility was lower (P< 0.01) in all RGS based diets compared to control diet, resulting in lower (P< 0.01) digestible crude protein (DCP) content in RGS diets. The total digestible nutrient (TDN) content of 30 or 40% RGS based diets was comparable to control diet. The calcium (Ca) balance was comparable but phosphorus (P) balance was lower (P< 0.01) in buffaloes fed 50% RGS diet. The intakes (g/kgW^0.75) of DCP and TDN were comparable among the groups and were higher than the standard Kearl (1982) requirements. The results of this study indicated that RGS could be incorporated in complete diets up to 40% level in buffaloes, while incorporation at 50% level depressed the nutrient digestibility and lowered the nutritive value.