Use of protease and xylanase in broiler diets containing distillers' dried grains with solubles

Abstract

Individual or combined effects of xylanase and protease on nutritive value of diets containing sorghum distillers dried grains with solubles (sDDGS) and fed to broiler chickens were investigated. A total of 480 day-old male broiler chickens were assessed in a 3 x 2 x 2 (0, 150 or 300 g sDDGS/kg diet, with or without xylanase, and with or without protease) factorial design. Each of the 12 treatments was replicated 5 times accommodating 8 birds per replicate. Feed intake (FI) and body weight gain (BWG) of the birds were increased by inclusion of sDDGS to the diets independent of enzyme supplementation. Feed conversion ratio (FCR) deteriorated as sDDGS was incorporated into the diets at both levels. Regardless of sDDGS and protease, xylanase significantly improved FCR. Digestibility of protein and most amino acids were adversely affected by inclusion of 150 and 300 g/kg sDDGS. While protease, individually, improved amino acid digestibility in birds offered diets containing the highest amount of sDDGS (300 g/kg), an admixture of xylanase and protease did not result in further improvement in amino acid digestibility. Addition of xylanase reduced the concentration of insoluble non-starch polysaccharides (NSP) in the ileum. Noticeably, the response of birds to xylanase supplementation on the concentrations of arabinose, xylose and total insoluble NSP was compromised when xylanase and protease were added to the diet simultaneously. To conclude, xylanase and protease in combination were effective for the growth performance of the birds on sDDGS, in particular improving FCR.