Evaluation of rice straw — poultry droppings based rations supplemented with graded levels of rice bran in fistulated buffaloes

The effect of supplementation of deoiled rice bran (DORB) at catalytic levels of 500 (D-1), 750 (D-2), 1000 (D-3) and 1250 (D-4) g along with a caged poultry droppings (CPD)-molasses-mineral mixture of 810 g and ad lib rice straw (0.704% nitrogen) was evaluated with four rumen fistulated graded Murrah (Bubalus bubalis) bull calves (176.5 ± 0.2) in a 4 × 4 latin square design using criteria such as in sacco degradability of rice straw, voluntary dry matter (DM) intake, apparent digestibility of nutrients and rumen parameters. Rumen degradation characteristics of DM and neutral detergent fibre (NDF) of rice straw were described by fitting the data to the exponential equation P = a + b[1 − e(−ct)]. men environment created by supplementation of DORB at 1000 g day−1 (D-3) to a rice straw-based diet increased (P < 0.05) the potential degradability (a + b) and rate of degradability (c) of DM and NDF of rice straw over those diets with 500 (D-1) or 750 (D-2) g day−1 of supplementation. mentation of DORB up to 1000 g (D-3) along with 500 g CPD and 250 g molasses to a rice straw-mineral diet significantly increased the DM intake of basal rice straw and total feed and digestibility of DM, crude protein (CP), NDF and acid detergent fibre (ADF) (P < 0.05) and organic matter (OM) (P < 0.01). The digestible crude protein (DCP) and total digestible nutrients (TDN) of diets 1, 2, 3 and 4, respectively, were 3.37, 50.47%; 3.75, 52.49%; 4.11, 56.47% and 3.88, 56.06% which were significantly (P < 0.05) influenced by the supplementation. The rumen parameters (averages of 0, 2, 4, 6 and 8 h postfeeding) revealed that pH and ammonia nitrogen (NH3N) of D-3 were conducive to rumen fermentative digestion of feed and total volatile fatty acid (TVFA) concentrations were positively correlated with the DM intakes of the animals. It is concluded that supplementation of DORB at 1000 g day−1 along with a poultry droppings-molasses-mineral mixture to rice straw maximizes the utilization of rice straw in buffaloes and thus paves the way to develop an economic feeding system.