Growth performance and macronutrient digestion in goats fed a rice straw based ration supplemented with fibrolytic enzymes

Supplementation of rice straw based rations (30% rice straw, dry matter basis) with fibrolytic enzymes is of potential interest to improve nutrient utilization and hence animal performance, but its efficacy is not yet demonstrated in growing goats. In a parallel design, eighteen young goats were fed a total mixed ration (TMR) based on rice straw either with or without supplemental fibrolytic enzymes. Addition of fibrolytic enzymes to the TMR increased the apparent digestibility of neutral and acid detergent fiber by 10.0 and 9.1%, respectively. Enzyme supplementation raised concentrations of total volatile fatty acids in rumen fluid with an associated increase in the proportion of acetate and total bacteria counts. Fortification of TMR with fibrolytic enymes increased average daily weight gain by 34.7% and the efficiency of feed utilization by 28%. It is concluded that the nutritive value of rice straw based rations can be upgraded by supplementation with fibrolytic enzymes, leading to enhanced ruminant production.