Effect of Heat Treatment on Rumen Degradability of Gliricia sepium leaves

Abstract

An experiment with the objective to investigate the effect of different temperature regimes during heat treatment of Gliricidia sepium leaves was conducted following a completely randomized design with 4 treatments and 3 replications. Gliricidia leaves were exposed to three temperature regimes namely oven heating at 60oC (T60), 90oC (T90), and 120oC (T120) respectively and followed by sun-drying compared to sun drying as control (Con). The dry matter and protein degradation were measured using In Sacco method in three fistulated Bali cows fed a standard diet. Protein solubility (a) and the insoluble but potentially degradable fraction (b) were linearly reduced (P<0,001) by the increased temperature in the oven as compared to sun drying. The degradation rate (c) of protein in the rumen was increased at all heating treatments. The effective dry matter and protein degradation of gliricidia leaf was significantly (P<0,01) reduced by heat treatment in T90 and no further reduction in T120. The solubility fraction of DM was significantly reduced (P<0.05) when heated in the oven at 120oC, meanwhile the b value for DM linearly decline with the increasing heating temperature. Heating also increased the lag time required for the degradation to commence. It, therefore, can be concluded that oven drying at 90oC is a simple effective means to reduce ruminal protein degradation of gliricidia leaves.