Ruminal and post ruminal digestion of protein supplements

Conventional (groundnut (GNC) and mustard cake (MC) and non-conventional protein supplements (castor oil seed cake (COSC), neem seed cake (NSC), corn gluten meal (CGM) were evaluated by in sacco technique. The degradability of DM and CP of all the protein supplements increased with the increase in incubation period in the rumen of buffaloes. The COSC was highly susceptible, whereas NSC and CGM were highly resistant to microbial degradation in the rumen. The digestion kinetic parameters worked for DM and CP revealed that GNC had the maximum and CGM had the minimum rapidly soluble fraction. The slow degradation rate of NSC and CGM was responsible for their high rumen un-degrad-able fraction and poor effective degradability in buffaloes. The in vitro intestinal digestibility of rumen un-degradable protein (irrespective of protein supplement) decreased with the advancement of rumen incubation time. The GNC and MC had higher (P<0.05) intestinal digestion as compared to rumen un-degrad-able fraction of these supplements. However, no such differences were observed between ruminally exposed or unexposed samples of NSC and CGM, indicating higher potential of these non-conventional protein supplements as rumen bypass proteins. The COSC and CGM had considerably higher intestinal absorbable protein as compared to other protein supplements. The CGM was observed to be the best protein supplement, which may be incorporated in the ration of high yielding ruminants.