Effects of Different Levels of Resistant Starch on Growth Performance and Ileum Morphology in Broilers: A Comparison to Fructooligosaccharide and Zinc Bacitracin

This study was conducted to examine effects of resistant starch compared to fructooligosaccharide (FOS) and zinc bacitracin (ZnB), on performance and ileum morphology in broilers. The experiment groups in-cluded a control (basal diet with no additive; CON), four groups receiving different levels of resistant starch type 2 (1, 2, 3, and 4% added to basal diet; RS), a group receiving fructooligosaccharide (0.4% in basal diet; FOS), and a group receiving Zinc bacitracin (50 mg/kg basal diet; ZnB). The findings on the day 35 indi-cated that the groups that received 2% and 3% RS were not significantly different from the FOS group and the ZnB group in terms of feed intake. The largest body weight and the smallest feed conversion ratio was found in the ZnB group (P<0.05). Body weights in the groups treated with 3% and 4% RS were not signifi-cantly different from the FOS group. The 3% and 4% RS groups had a greater villus height (P<0.05) and a smaller crypt depth compared to the FOS group. These results demonstrated that while the ZnB group had a better performance than other groups, it seems that adding 3% and 4% RS resulted in a performance similar to adding FOS.