Effect of (Leucaena leucocephala) Leaves as Tannin Source on Rumen Microbial Enzyme Activities and in Vitro Gas Production Kinetics

Leucaena leucocephala has become one legume most commonly used in ruminant feeding practices and which contains CT with potential to reduce CH4 emissions, improve feed protein utilization. This study was aimed to determine the effect of L. leucocephala leaves as a tannin source on rumen amylase, CMC-ase, β-glucosidase, protease activity and kinetic of gas production. The study began with tannin protein-binding capacity evaluation. The levels of L. leucocephala leaves which used were 0, 10, and 25. Feed fermentation was conducted using Menke and Steingass gas production technique for 48 hours. Kinetic of gas production was analyzed using the Fit Curve programme. Data obtained were analyzed using one way ANOVA, and continued by DMRT. The results of this study showed that the tannin protein-binding capacity was 1.2680 mg BSA/mg DM of L. leucocephala leaves. Amilase, CMC-ase, β-glucosidase, and protease activity decreased significantly (P<0.01) at 10 and 25 L. leucocephala. Gas production from soluble fractions (a) was not affected by the treatment. Gas production from the potentially degraded fraction (b) decreased significantly (P<0.05) at 10 and 25 L. leucocephala . The potential extent of gas production (a+b) decreased significantly (P<0.05) at 25 L. leucocephala. The gas production rate (c) increased significantly (P<0.05) at 25 L. leucocephala. Inclusion up to 25 of L. leucocephala leaves in the diet reduce rumen hydrolytic enzymes activity, the soluble and the potentially degraded fraction (a+b) and gas.