Effects of corn distillers dried grains with solubles and xylanase on growth performance and digestibility of diet components in broilers

The objective of this study was to investigate the effect of corn distillers dried grains with solubles (cDDGS) and xylanase in corn-based diets on growth performance and digestibility of diet components in broiler chickens. The experiment was a 3×4 factorial design with diets containing 3 levels of cDDGS (0, 100 and 200 g/kg) and 4 levels of xylanase (0, 1200, 2400 and 3600 U/kg). The diets were fed to 720 Cobb 500 chicks for 42 days. Excreta was collected at 18-21 days to measure coefficients of total tract apparent digestibility (CTTAD) and ileal digesta was collected at 42 days to measure coefficients of ileal apparent digestibility (CIAD). Dietary cDDGS caused poor (P<0.05) feed conversion ratio (FCR) of broilers from 1 to 21 and 22 to 42 days, but increased (P<0.05) feed intake (FI) at 1-21 days. Inclusion of xylanase increased (P<0.05) FI by 4-5% at 1-21 days, and did not affect (P≥0.05) FCR in either period. In the two growing periods, cDDGS decreased (P<0.05) the CTTAD of dry matter (DM), and the CIAD of DM and hemicelluloses, whereas xylanase increased (P<0.05) the digestibility of DM and hemicellulose by 5% and 20%, respectively. There were significant interactions (P<0.05) between cDDGS and xylanase for BWG and energy digestibility. In comparison with the 100 g/kg cDDGS diet, the inclusion of 200 g/kg cDDGS led to poorer (P<0.05) FCR at 22-42 days, and lower (P<0.05) CTTAD of DM at 18-21 days. There were no differences (P≥0.05) in most growth parameters between the doses of xylanase at 1200, 2400 and 3600 U/kg. Xylanase at 2400 U/kg increased (P<0.05) CTTAD of DM compared with the lower dose, but 3600 U/kg xylanase showed no further improvement (P≥0.05) on digestibility measurements. The results suggest that supplementing xylanase to diets containing cDDGS can improve growth performance and digestibility of diet components in broilers.