Urea treated cocoa pod as barley grain substitution in ruminant ration on microbial metabolism and feed degradation (Rusitec Study)

Abstract

Limited sustainable supply of high quality feedstuff is the major constrain in ruminant production in most of tropical countries. Aim to convert underutilized cocoa pod to quality feedstuff and its inclusion in ruminant ration have been done. Cocoa pod was treated with 20 g urea per kg fresh material. The effects of replacing barley grain by urea treated cocoa pod on methane release, SCFA production as well as the amount and efficiency of microbial-N fixation in Rusitec have been studied. The experiment included six different rations (T1 = 10 g/d hay; T2 = T1 + 4 g/d barley-soybean mixture (barley); T3 = T1 + 3 g barley + 1 g cocoa pod); T4 = T1 + 2 g barley + 2 g cocoa pod; T5 = T1 + 1 g barley + 3 g cocoa pod and T6 = T1 + 4 g cocoa pod) and three running of Rusitec in a block random design. Substitution of barley by urea treated cocoa pod up to 100% in hay based rations did not decrease the rate of ration DM disappearance, and fiber degradation even tended to be increased. Microbial N-fixation decreased with the inclusion of cocoa pod in the rations, but the efficiency of microbial N-fixation was increased in line with the cocoa pod level. Methane release per unit NDF disappearance decreased inversely to the cocoa pod level. Urea treated cocoa pod cannot replace barley/soybean meal-mixture equivalently, but can be used as a feedstuff for low performance ruminants.