Effects of wet feeding and enzyme supplementation on nutritional value of wheat screenings for broiler chickens

The effects of wet feeding and a multi-enzyme preparation on the nutritional value of wheat screenings (WS) for broiler chicks were investigated. In total, 540 1-day-old Ross-308 broiler chicks were fed a corn–soybean meal-based diet up to 29 days of age. At that time, the birds were randomly assigned to nine diets in a completely randomised design with a 3 × 3 factorial arrangement, including three levels of WS (0%, 25% and 50%, WS0, WS25 and WS50 respectively) and three processing methods (no processing, enzyme supplementation and wet feeding). The enzyme mixture contained endo-1, 4-β-xylanase (200 FXU/g), endo-1, 4-β-glucanase (50 FBG/g), endo-1, 8-β-glucanase (21 FBG/g), hemicellulase (3000 VHCU/g), α-galactosidase (3 GALU/g) and protease (260 U/g) and was supplemented at a level of 6 g/kg of diet. The inclusion of water in wet diets was in the extent of 1.2 kg/kg of diet. During the period from 29 to 49 days of age, feed intake was not affected (P > 0.05) by the inclusion of WS in the diet, whereas chicks fed the WS25 diet had a higher (P < 0.05) bodyweight gain than did those on WS0 diet. The feed conversion ratio (FCR) was improved (P < 0.05) by the inclusion of WS in the diet throughout the study. The feed intake was increased (P < 0.05) by enzyme supplementation to WS50 diet, while bodyweight gain was increased (P < 0.05) by wet feeding. Enzyme supplementation did not affect (P > 0.05) FCR, whereas wet feeding resulted in lower (P < 0.05) FCR over the entire study. The plasma concentration of glucose was increased (P < 0.05) by the inclusion of WS in the diet. The viscosity of the ileal digesta was higher (P < 0.05) in chicks receiving the WS50 diet than that in chicks receiving the other diets. The jejunal villus height was increased (P < 0.05) and the jejunal crypt depth was decreased (P < 0.05) by the inclusion of WS in diet. The jejunal crypt depth was greater (P < 0.05) in chicks receiving the wet diets than in chicks receiving the enzyme-supplemented diets (P > 0.05). In conclusion, the results from the present study indicated that broiler growth performance was improved by the inclusion of WS in the diet and also by wet feeding. These effects were largely compatible with the changes that occurred in the small intestine morphology, but not with those observed for ileal digesta viscosity.