Document Type : Research Paper
Assistant Professor, Department of Animal Science, Faculty of Agriculture and Natural Resources, Razi University, Kermanshah, Iran
Former M.Sc. Student, Department of Animal Science, Faculty of Agriculture and Natural Resources, Razi University, Kermanshah, Iran
Monogastric Research Center, School of Agriculture and Environment, Massey University, Palmerston north 4442, New Zealand
This study was conducted to evaluate the effect of corn particle size and different insoluble fiber sources on performance and carcass and gastrointestinal tract characteristics of broilers from 1 to 21 days of age. A total of 660 male broilers were used in a 2×3 factorial arrangement with 6 treatments and five replicates per treatment. The factors of interest were two corn particle sizes (2 and 6 mm) and three insoluble fiber sources (lignocellulose, rice hull, RH and sunflower hull, SFH). The main effect of fiber source was significant for the body weight gain (P<0.01) and feed conversion ratio, with SFH inclusion improved BWG (P<0.01) and FCR (P<0.01) compared to OH and lignocellulose. The supplementation of lignocellulose (P<0.05) and fine particles (P<0.01) resulted in higher carcass weight compared to other fiber sources and coarse particles, respectively. Feeding lignocellulose increased (P<0.01) the weight of the small intestine than the other two fiber sources. The Experimental treatments had no significant effect on the relative length of small intestinal segments. Coarse grinding of corn and SFH inclusion reduced gizzard pH when compared to fine grinding and lignocellulose inclusion, respectively (P<0.05). The Gizzard weight of birds fed a diet containing lignocellulose and SFH was significantly higher (P<0.01) those fed RH. Generally, the dietary inclusion of 3% SFH improves growth performance through improved weight and reduced pH of gizzard and can be practically used in the broiler industry.