Effect of dietary fiber on intestinal morphology and performance of broiler chickens

In this experiment، 560 day old male broilers (Ross 308) in a completely randomized design were used to study the effect of two fiber sources (processed fiber and corn hull) at inclusion levels of 3، 4، and 5 g/kg of diet on the performance and intestinal morphology. In all three sections of small intestine the maximum number goblet cells، villus height and ratio of villus height to crypt depth and minimum crypt depth were observed in processed fiber groups especially at 5 g/kg of processed fiber. Growth rate and feed efficiency were improved when diets contained 5 g/kg of processed fiber (P<0. 01). It was shown that there were an increasing linear regression between levels of processed fiber inclusion in the diet and goblet cell numbers، villus height and ratio of villus height to crypt depth in all intestinal sections and body weight gain. A similar but decreasing linear regression was observed for feed efficiency. There was an increasing linear response between corn hull levels and crypt depth، feed efficiency and feed intake. A decreasing linear response was evidenced for villus height and ratio of villus height to crypt depth. In conclusion، the processed fiber behaves in a different manner from conventional fiber in terms of small intestinal morphology and performances. The superior performance of processed fiber fed birds could be attributed to healthier small intestine، especially at supplementation level of 5 g/kg.