The catalytic effect of supplementation of protein meals on utilization of rice straw poultry droppings rice bran diet in buffaloes

Four graded Murrah (Bubalus bubalis) bull calves (198.5 +/- 3.0 kg) fitted with permanent rumen cannulae were used in a 4 X 4 latin square design to study the effect of supplementation of protein meals viz., groundnut cake (D-2), soyabean meal (D-3) or fish meal (D-4) at 100 g each to caged poultry droppings (CPD)-molasses-deoiled rice bran (DORB)-mineral (1810 g) mixture (D-1) and ad lib rice straw on in sacco rumen degradability of rice straw, voluntary feed intake, nutrient utilization and rumen fermentation pattern. Rumen degradation characteristics of dry matter (DM) and neutral detergent fibre (NDF) of rice straw (RS) and DM and crude protein (CP) of protein meals were described by fitting the in sacco data to the exponential equation p = a + b(1 - e(-cl)). Rumen environment created by groundnut cake (GNC), soyabean meal (SBM) and fish meal (FM) supplementation increased (P < 0.10) the rate of DM degradability (c) of straw by 23.4%, 27.6% and 15.8%, respectively. Effective protein degradability of protein meals revealed that GNC protein was highly rumen degradable (93.2%) while FM protein was less degradable (49.2%) with SBM protein being intermediate (82.1%). Rates of protein degradability of GNC, SBM and FM were 0.1927, 0.2399 and 0.0720, respectively. Protein meal supplementation non-significantly increased rice straw and total DM intake (DMI) and significantly increased the DMI as a percentage of body weight (P < 0.05) and per kilogram of metabolic body size (P < 0.10). Voluntary DMI of buffaloes per kilogram W-0.75 was 81.9, 88.9, 89.6 and 91.0 g for D-1, D-2, D-3 and D-4, respectively. The apparent digestibilities of DM, OM, CP, NDF, acid detergent fibre (ADF) and cellulose were increased (P < 0.01) due to supplementation of protein meal. It further increased the consumption of digestible crude protein (DCP) (P < 0.01), metabolizable energy (ME) and DOM (P < 0.05) and N retention (P < 0.01) of buffaloes kept on RS diet. Animals fed FM diet had lower urinary N excretion and higher (P < 0.01) N retention. Rumen NH3-N concentration was significantly lower (P < 0.01) in animals fed D-4 while animals fed D-3 or D-4 had significantly higher (P < 0.01) total volatile fatty acid (TVFA) concentration. It is concluded that supplementation of RS-CPD based diet with various protein meals improved the performance of buffaloes with FM protein being superior in comparison with protein from GNC or SBM.