Feeding dietary non-starch polysaccharides supplemented with xylanase could improve the performance of broilers
The impact of dietary non-starch polysaccharides (NSP) on performance and carcass traits of broilers fed wheat-bran substituted into corn-soybean meal-based diets supplemented with xylanase was investigated. A total of 280 (7-day-old) Ross 308 broilers were randomly allotted to one of five dietary treatments with 8 replicates, 7 chicks per pen. Treatments were; i) CON: Control diet, ii) CON-X (CON + 3,000 U/kg xylanase), iii) L-X: low NSP (2% wheat bran in CON + 3,000 U/kg xylanase), iv) M-X: medium NSP (4% wheat bran in CON + 3,000 U/kg xylanase), v) H-X: higher NSP (8% wheat bran in CON+ 3,000 U/kg xylanase). Birds fed the H-X diet increased (<italic>p</italic> < 0.05) daily gains, and average daily feed intake and had marginally improved body weights (<italic>p</italic> = 0.074) on day 35. Relatively, the H-X diet tended to increase the average daily gains (<italic>p </italic>= 0.053; <italic>p</italic> = 0.073) of birds during the grower phase (d 24-35) and the entire experimental period (d 8-35), respectively. Moreover, there were no significant differences among treatments in the feed conversion ratio of birds throughout the entire experiment period. Birds fed diets CON-X, L-X, and M-X had improved (<italic>p </italic>< 0.05) the ileal digestibility of energy on d 24 and 35 compared to those fed the H-X diet. Furthermore, birds fed diet CON-X improved (<italic>p</italic> < 0.05) N digestibility on d 24. Improved carcass moisture content and lowered crude fat of leg meat (<italic>p</italic> < 0.05) were noted in birds fed the diet M-X and H-X on d 35, respectively. The intestinal viscosity was reduced (<italic>p </italic>< 0.05) in xylanase-supplemented treatments CON-X, L-X, M-X, and H-X diets when compared to CON. Our results suggest that supplementing 3,000 U/kg xylanase in a higher NSP (8% wheat bran substituted level) diet could improve the intestinal viscosity and growth performance of broilers.