IN VITRO EVALUATION OF DIETS OF BUFFALOES CONTAINING DRIED DISTILLERS GRAINS WITH SOLUBLES AS A SUBSTITUTE FOR SOYBEAN MEAL

In vitro studies were carried out to investigate the effect of using dried distillers grains with solubles (cereal milling by-product) as a substitute for soybean meal (SBM) in the diet of buffaloes. SBM comprising 6% of the whole diet (total mixed ration; TMR) was substituted by rice dried distillers’ grains with solubles (RDDGS) at five levels (0, 25, 50, 75 and 100%) on N basis. In vitro dry matter disappearance (IVDMD), organic matter disappearance (IVOMD), net gas production (NGP), methane production and fermentation efficiency of TMRs was studied. RDDGS substitution at 25, 50 and 75% significantly increased (P<0.05) IVOMD and IVDMD. The NH3-N decreased (P<0.05) with the increasing level of RDDGS in the TMRs. The relative proportion (%) of acetate declined (P<0.05) and that of propionate increased (P<0.05) with the increasing level of RDDGS in the TMRs and subsequently the A: P ratio declined (P<0.05) with RDDGS inclusion beyond 25% level replacing SBM in the TMR. No significant effect of RDDGS inclusion was observed on methane production. The fermentation efficiency increased (P<0.05) with the increasing level of RDDGS in TMRs. In conclusion, RDDGS could replace up to 75% of the soybean meal in the TMR of buffaloes which is equivalent to 4.5% of the whole dietary DM