In vitro Methane Production Potential and in sacco Degradability of Energy Feeds

The present study was undertaken to assess the in-vitro methane production potential and in-sacco degradability of conventional (wheat, maize, barley, jowar/sorghum and bajra/pearl millet) and non conventional (waste bread) energy feeds. Maize grains had the lowest CP content while wheat grains had the highest CP (12.9%), which was comparable with waste bread (12.4%). In vitro gas production studies revealed that net gas production was highest (P<0.01) from wheat grains and lowest from sorghum. The methane production (expressed as ml/100mg DM) was the lowest (P<0.01) in case of bajra (4.79 ml/100mg DM) and highest in barley (5.59 ml/100mg DM). When methane production was expressed as ml/100mg digestible OM at t½, significantly lowest methane production was observed from waste bread (0.55ml/100mg DOM at t½) comparable with that of barley followed by that from bajra and sorghum. The partitioning factor (PF) was highest in waste bread indicating proportionally more of the degraded matter will be incorporated in microbial biomass. Sundried waste bread produced the highest (P<0.01) TVFAs, acetate and propionate as compared to other energy supplements. The in sacco studies revealed that the sundried waste bread possessed the highest (P<0.01) amount of true degradability, apparent and potential extent of digestion of DM as compared to other energy supplements. The sundried waste bread had the lowest (P<0.01) rumen fill values, predicting higher DM intake potential as compared to all other energy supplements. The rumen undegradable protein (UDP) as well as UDP as percent of CP was highest (P<0.01) in sorghum followed by that in waste bread. Sundried waste bread, barley and bajra were considered as promising energy supplements for livestock. Further, utilization of sundried waste bread will economize the dairy rations and costly cereal grains could be spared for more vulnerable animal species.