PSII-19 Effect of dietary supplementation of xylanase alone or combination of xylanase and β-glucanase on growth performance and intestinal measurements in broiler chickens

Abstract Poultry feeds primarily comprise plant ingredients such as cereal grains and cereal by-products that are high in non-starch polysaccharides (NSPs). However, poultry has limited digestive enzymes to efficiently utilize NSPs, and therefore, exogenous NSP-degrading enzymes (NSPase) are typically supplemented to poultry diets. Xylanase is the most widely used as NSPase in poultry diets because xylanase degrades arabinoxylans which is in increased amounts in most feed grains like corn and wheat, thereby improving dietary nutrient utilization and subsequent productive performance. β-glucanase is another potential exogenous NSPase used to degrade β-glucans present in plant ingredients. Although the benefits of dietary xylanase are well-documented, limited information regarding effects of dietary xylanase and β-glucanase complex is available. Therefore, this study aimed to investigate the effect of dietary supplementation of xylanase alone or combination of xylanase and β-glucanase on growth performance and intestinal measurements in broiler chickens. A total of four hundred 8-d-old male and female Ross 308 broiler chicks were randomly allotted to 1 of 4 dietary treatments with 10 replicates. Each replicate had 5 male and 5 female birds. Dietary treatments included a positive control (PC) diet with adequate energy and nutrients, a negative control (NC) diet with high NSP-containing ingredients and less AMEn by 100 kcal/kg than PC diet, and 2 NC-based diets supplemented with 0.1% xylanase (4,000,000 units/kg) or 0.1% xylanase-glucanase complex (4,000,000 units/kg xylanase and 2,000,000 units/kg β-glucanase). The experiment lasted for 28 d. For intestinal measurements including jejunal morphology and ileal digesta viscosity, 1 male chicken per replicate was selected based on the body weight at the end of the experiment. Results indicated that birds fed PC diets had less (P < 0.05) FCR than those fed NC diets (Table 1). Birds fed diets supplemented with xylanase alone or combination of xylanase and β-glucanase had also less (P < 0.05) FCR than those fed NC diets. No difference in FCR was observed between birds fed PC diets and those fed diets supplemented with xylanase alone or combination of xylanase and β-glucanase. However, dietary treatments had no effects on body weight, body weight gain, and feed intake of broiler chickens. Jejunal villous height to crypt depth ratio (VH:CD) was greater (P < 0.05) for birds fed PC diets or diets supplemented with combination of xylanase and β-glucanase than those fed NC diets (Table 2). Feeding diets supplemented with xylanase alone or combination of xylanase and β-glucanase decreased (P < 0.05) ileal digesta viscosity as compared with feeding NC diets (Table3). In conclusion, feeding high NSP and low energy diets supplemented with either 0.1% xylanase alone or 0.1% xylanase and β-glucanase complex results in similar productive performance of broiler chickens as compared with feeding typical corn-soybean meal-based diets possibly due to improved intestinal structure and decreased digesta viscosity.