Enzyme supplementation of low or high crude protein concentration diets for broiler chickens

Abstract

ABSTRACTPrevious investigations have established that supplementing broiler chicken diets with appropriate endosperm cell wall degrading enzymes can improve nutrient digestion, and indicated that this could allow lower protein diets to be used. In this study the effect of enzyme supplementation on the productive value of low (192 g/kg dry matter (DM)) and high (227 g/kg DM) protein diets was studied. The diets employed were based on barley, wheat and rye, and the two enzyme preparations used, Glucanase GP 5000® and Novozym-343®, contained β3-glucanase and arabinoxylanase activities.The high protein diet gave a higher incidence of sticky droppings, but resulted in a higher growth rate and improved food conversion ratio than the low protein diet. Enzyme supplementation reduced the incidence of sticky droppings and also improved growth rate, food intake and food conversion efficiency for both diets, with the Glucanase GP 5000 preparation generally being more effective. Enzyme supplementation improved growth rate on the low protein diet to a level equal to or better than that on the high protein diet, although this was achieved by a better food intake and an inferior food conversion ratio. This study demonstrated that supplementation with appropriate enzymes could allow a reduction in dietary protein level without affecting broiler growth rate.