Effect of Fat Content in Various Oil Cakes on Rumen Fermentation

Degradable nitrogen, methane production and fermentation end-product profiles from fat variable substrates constituted by expeller and solvent extracted oil cakes in five ratios were estimated using in vitro rumen fermentation. In vitro degradable nitrogen, total gas and methane production declined (P<0.05) -with an increase In fat content of substrates. The mean nitrogen degradation was highest (75.6%) in groundnut cake and least (64.9%) in cotton seed cake. Methane production was highest with groundnut cake substrate (18.1 ml/200 mg DM) followed by cottonseed cake (17.1),sunflower cake (15.7) and mustard cake (15.5). Methane production increased by 21.1 per cent (mustard cake), 31.5 per cent (cotton seed cake), 38.2 per cent (sunflower cake) and 40.5 per cent (groundnut cake) wlien expeller cakes were wholly replaced by solvent extracted oil cakes. Rnmtnal acetate and butyrate production linearly increased with the level off solvent extracted oil cakes while propionate production declined with an increase in the contents of such supplements.