Effects of Fructooligosaccharides,compared with Direct—Fed Microbial Bacteria,and Zinc Bacitracin on Cecal Microbial Populations and Performance of Broilers

An experiment was conducted to determine the effects of dietary fructooligosaccharides(FOS),compared with direct-fed microbial bacteria (DFM),and zinc bacitracin ,on cecal microbial populations and performance of broiler Chickens. One hundred and ninety-two broilers (Avian) were randomly assigned to four groups,with four replicates of 12 birds each. The control group was fed with the basal diet,without any drug additive. FOS,DFM and zine bacitracin was respectively added to the basal diet at the level of 1.5% ,800 mg@kg-1 and 300 mg@ kg-1 to form the experimental diets. Body weight ,feed intake and feed efficiency were measured weekly. The feeding trial started at 1 d and ended at 21 d. At day 14 and day 21 ,four broilers per group were killed and cecum waa taken to determined microflors and pH. The results showed that dietary FOS increased bifidobactrial concentration by 1. 75-fold( P ＜0. 05) at 14 d of age and 1.45-fold( P ＜0. 05) at 21 d of age compared with control. FOS had no effect on concnetrations of E. coli and pH. There were no dietary effects of FOS,DFM,and zinc bacitracin on weight gain,feed intake,feed conversion( P ＞0. 05).