The influence of inclusion of pellet binder on physical pellet quality, growth performance, carcass characteristics and total tract apparent retention of nutrients was examined. Broiler starter (Days 1–21, pellet diameter: 2.5 mm) and finisher (Days 22–42, pellet diameter: 4 mm) diets were formulated and then allocated to one of the seven treatments including control diet, and diets including sodium bentonite (10 and 20 g/kg), wheat gluten (10 and 20 g/kg) and wheat (100 and 200 g/kg). All ingredients used as a pellet binder significantly (P < 0.05) increased the pellet-durability index compared with control diet. Wheat gluten and wheat at both inclusion rates were significantly (P < 0.05) more efficient than was sodium bentonite in improving pellet hardness. From Day 1 to Day 42, chickens fed 10 g/kg wheat gluten and 100 and 200 g/kg wheat gained significantly (P < 0.05) more weight than did control. During starters, birds fed 200 g/kg wheat showed the highest feed intake (P < 0.05). On Day 42, all the pellet binders resulted in a heavier heart weight than in the control (P < 0.05). At Day 21, the length of ileum was significantly (P < 0.05) higher in birds fed 10 and 20 g/kg sodium bentonite, 10 g/kg wheat gluten and 200 g/kg wheat, but at Day 42, it was greater in birds fed 20 g/kg wheat gluten and 200 g/kg wheat than in those fed the control diet. Inclusion of wheat gluten (10 and 20 g/kg) and wheat (100 and 200 g/kg) increased (P < 0.05) fat apparent retention. Birds fed 20 g/kg wheat gluten had a significantly (P < 0.05) higher total tract apparent retention of crude fibre, also calcium apparent retention improved by wheat gluten inclusion at concentrations of 10 and 20 g/kg compared with control (P < 0.05). Overall, inclusion of 10 g/kg wheat gluten, and 100 and 200 g/kg of wheat improved physical pellet quality and weight gain in broilers.
Dietary soybean meal on growth and intestinal morphology of South American catfish, Rhamdia quelen, larvae
