Viscosity and growth response of broilers fed high fiber diets supplemented with a corn-produced recombinant carbohydrase

Feed ingredients containing high levels of non-starch polysaccharides (NSP), such as wheat and corn distillers’ dried grains with solubles (DDGS), can form viscous digesta in the gastrointestinal tract, limiting broiler performance. A study was conducted to determine efficacy of a corn-produced recombinant carbohydrase (AC1) on dietary and intestinal viscosity and broiler performance with a high NSP diet. Hubbard × Ross 708, a day old, male broiler chicks (n = 960) were fed 1 of 8 dietary treatments for 21 d. Diets included a corn–soybean meal based diet (PC_1) and a diet of similar essential nutrient density, but with a 10% inclusion of both wheat and DDGS (PC_2) and a negative control (NC) with similar ingredients as PC_2, but with ME reduced by 125 kcal/kg. Additional treatments had varying levels of AC1, supplying 50, 100, 200, 400, or 600 U β-Glucanase (β-Glu-U) per kg of feed, mixed into the NC diet. Dietary and digesta (d14) viscosity and weekly bird performance were measured. The inclusion of wheat and DDGS increased d1–7 feed conversion ratio (FCR) and supplementing AC1 at 50–400 β-Glu-U/kg reduced FCR equivalent to PC_1. Intestinal viscosity correlated with d1–21 FCR and inversely correlated with d1–21 live weight gain (LWG). When analyzed categorically, dietary viscosity inversely correlated with d1–21 LWG (P < 0.05). This study demonstrates that AC1 can reduce intestinal viscosity and improve early FCR in birds fed high viscosity diets and that in vitro viscosity can correlate to broiler performance.