Effect of non-conventional dietary insoluble fiber on growth, nutrient digestibility, intestinal morphology, and carcass traits of male broilers

The effects of including wheat bran (WB), corn bran (CB), and corncobs (CC) (as sources of insoluble fiber) at two levels (2 and 4%) in the diet on growth performance, nutrient digestibility, carcass traits, and intestinal morphology were examined in male broilers from1 to 42 days (d) of age. A total of 294 one-day-old male Cobb-500 chickens were assigned to seven dietary treatments (a control diet and six diets containing WB, CB, or CC at 2 or 4%) with six replicates per treatment in a completely randomized design. The six fiber-containing diets were also analyzed as a 3 × 2 factorial arrangement to evaluate the effects of fiber source and inclusion level. From 1 to 42 days of age, FI for birds fed CC was statistically lower than for birds fed WB, CB, or control (P < 0.001). In the same period when CB was used as a source of insoluble fiber, growth traits, the ratio of villus height to crypt depth (VH: CD), apparent digestibility of the ether extract and crude protein improved significantly, which was more noticeable at the 4% level (P < 0.001). Birds that used fiber diets had more extended villus height than the control, and the highest VH: CD was observed at 4% WB, followed by 4% CB diet (P < 0.001). Growth traits, nutrient digestibility, and VH: CD increased with increasing fiber levels from 2 to 4% (P < 0.05). The CB-containing diet showed superior performance to the other sources, and its moderate inclusion maintained bird performance comparable to the control.