Effect of different levels of acacia nilotica pods on in-vitro digestibility of total mixed rations

Total mixed rations (TMR) containing 0, 4, 6, 8, 10, 12% tannin using Acacia nilotica pods were assessed in vitro for nutrient digestibility and gas production. In vitro DM digestibility ((VDMD) and OM (IVOMD) was not affected by tannin up to 8% level, but reduced (P<0.05) thereafter. In vitro CP digestibility (IVCPD) depressed (P<0.05) with increased levels of tannins in TMRs and depression was much more pronounced at 4% tannin level and thereafter reduction was stable up to 10% tannin. In vitro gas production (IVGP) was also reduced (P<0.05) with increased levels of tannins during first 24h of incubation and tended to increase (P>0.05) during 24-48h of incubation. Phloroglucinol and resorcinol were the major end products of tannin degradation while gallate and catechin was produced in traces. It was concluded that tannins of Acacia nilotica pods reduced the in vitro nutrient digestibility; however,uminal microbes of buffalo were capable to degrade the tannin of Acacia nilotica pods without pre exposure to this diet.