Effects of Different Sources and Particle Size of Dietary Fiber on Performance, Small Intestine Morphology, Secum Bacteria and Digestive Enzymes in Broiler Chickens

Inorder to evaluate the effects of four sources of fiber (soy hulls, barley hull, rice husk and corn husks) each with two particle size (with 1 and 2- mm of geometric mean) on performance, nutrient digestibility, some blood parameters, small intestine morphology and secum bacteria in broiler chicken, 540 Ross308 broiler male chicks from 1 to 42 days were used in a completely randomized design with a factorial arrangement 2×4, with nine treatments (one control treatment), four replications and 15 broilers in each replicate.Weight gain in the starter and finisher periods, feed intake during the finisher and the whole period, and feed conversion ratio in the growr, finisher and the whole period of breeding were affected the entire fiber source. The treatment with coarse barley hull had more weight gain, lower feed intake, and less conversion ratio (P<0.05). The most unfavorable feed conversion ratio observed in treatment containing rice husk. Crude protein (P<0.0493) and ether extract (P<0.0004) digestibility in corn husks fed diets was higher than other treatments. In duodenum, jejunum and ileum, the highest and lowest villus height were observed in barley hull treatment and control group, respectively (P <0.05). The depth of crypt was affected only in the jejunum and crypt diameter in all three parts of the intestine (P<0.05). The number of intestinal Lactobacilos in the chiks fed diets containing corn and barley hulls was significantly more than those fed with diets containing soya and rice hull. The fibers particle size had significant effect on E.Coli and coliform bacteria (P<0/007). However, with adding a fiber source such as barley or corn hull, to broiler diets would have beneficial effects in yield, health and welfare of the bird.