In Vitro Methane Production Potential of Cereal Brans

The present study was undertaken to assess in vitro methane production potential and in sacco degradability of rice bran (RB), deoiled rice bran (DORB) and wheat bran (WB). The net gas production (NGP), true OM and NDF digestibility, total volatile fatty acids (TVFAs) and individual VFAs production was the highest (P<0.01) in WB followed by that in DORB and the lowest (P<0.01) in RB. The methane production estimated at t½ was the highest (P<0.01) in DORB followed by that in WB and the lowest in RB. The ME availability was highest in WB and lowest in DORB. The digestion kinetic parameters for DM, assessed by in-sacco technique, revealed that WB had the highest (P<0.01) rapidly soluble fraction and the lowest insoluble but potentially degradable fraction. The WB had the lowest (P<0.01) undegradable fraction and the highest (P<0.01) effective degadability (ED). The DORB and WB had comparable rumen fill values but significantly (P<0.01) lower than RB predicting higher voluntary DM intake in WB and DRB as compared to RB. The digestion kinetic parameters for CP revealed that WB had the highest (P<0.01) amount of rapidly soluble fraction and the lowest (P<0.01) amount of insoluble but potentially degradable protein fraction. The RB had the lowest (P<0.01) amount of rumen undegradable protein (UDP) and ED protein. It was concluded that rice bran had the lowest methane production potential but considering all other parameters like digestibility of nutrients, VFAs production, ME availability and UDP content, wheat bran was considered as the best amongst the tested brans.