Common feed resources were evaluated by chemically and in vitro gas production method. The rumen mixed microbe inoculums source was taken from fistulated native steers. The cumulative gas volume 24h after incubation was highly significant (p<0.01) and estimated Metabolizable Energy (ME) ranged 6 to11, 4 to 11 and 9 to 11 mega jule (MJ) kg-1 dry matter (DM) for legume, non-legume and concentrate feedstuffs respectively. Oil cake and whole grain maize and khasari possessed significantly higher (P<0.01) ME than bran. Crop residue, rice straw contained very low ME reflecting high acid detergent fiber (ADF). The non-legume grasses exhibited moderate gas volume and estimated comparatively medium ME. Similarly legume grasses exposed the greatest gas production and estimated highest (6-12 MJ kg-1). Concentrates showed the great potentiality for crude protein (CP), digestible energy (DE) content and organic matter digestibility (OMD). The lowest ME value (3.8 MJ kg-1 DM) was found in rice bran among concentrates. Non legume grasses contained 38-48 % ADF, 52-54% neutral detergent fiber (NDF), 6-7.5 MJ kg-1 DM. The jamboo grass showed higher OMD, contained significantly higher ME (MJ kg-1) followed by napier grass while maize and oat contained lower ME. All non-legume fodder contained 7-9.5% CP which was the highest CP (9.51%). Albeit, legume contained less ADF (30-46%) and NDF (34-55%) but higher CP (9.51%). The dhaincha was rich in CP content (26%) than bean or French bean and the ipilipil contained the lowest CP (16.71%). Concentrate feed stuffs maize, mustard oil cake, khasari and anchor husk had higher ME values (11.41, 11.54 and 10.92 MJkg-1 DM respectively). The difference of ME of various feedstuffs reflected different contents of fermentable carbohydrates and available nitrogen in cereals and protein supplements. The CP contents were 7 to 9.5, 17 to 26 and 11 to 35.5 % for non-legume roughage, legume roughage and concentrate feedstuffs respectively. The khasari bran, jamboo fodder, alfalfa had the highest NDF and ADF values. The OMD ranged from 52 to 83 % for concentrate except rice bran; 46-56% for non-legume roughage, 50-80% for legume roughage. Results of the present study suggest that a wide nutritional variation are existing among feed sources and potential sources might be considered prior to feeding ruminants.
Key words: Feedstuffs, nutritive value, in vitro technique