The Effect of Corn-Expressed Carbohydrase on Performance and Digesta Viscosity of Broilers Fed a High Non-Starch Polysaccharide Diet

Abstract

Study objectives were to determine the effects of a corn-expressed recombinant carbohydrase (AC1) on broiler performance and digesta viscosity in high non-starch polysaccharide (NSP) diets through 21 d of age. One day-old Hubbard × Cobb 500 chicks were assigned to 6 dietary treatments. Each treatment consisted of 12 replicate pens of 10 birds. The positive control diet (PC) was a corn and soybean meal formulation. The negative control diet (NC) included 10% wheat and 10% corn distiller's dried grains with solubles (DDGS). The NC contained 100 kcal/kg less ME than the PC. Increasing inclusions of AC1 were applied to the NC to contain 50, 100, 200, and 400 U β-glucanase (β-Glu-U) per kg of feed. Preliminary experiments demonstrated AC1 homogeneity and stability post pelleting. Live weight gain (LWG) was the highest for PC fed birds from 1 to 14 d; however, birds fed NC with 400 β-Glu-U/kg had similar LWG as PC (P > 0.05). Day 1 to 21 FCR was lowest for PC fed birds; however, birds fed NC with 400 β-Glu-U/kg had similar FCR as PC (P > 0.05). Birds fed NC had lower LWG and higher viscosity than birds fed PC on day 14 (P < 0.05), but not on day 21 (P > 0.05). Birds fed NC with 200 or 400 β-Glu-U/kg had similar 14 d digesta viscosity as birds fed PC (P > 0.05). These data indicate that NSP ingredients may have a greater impact on digesta viscosity early in broiler growth and that AC1 at 200 and 400 β-Glu-U/kg produced similar results to PC.