Effects of Bacillus on production performance,immunity and intestine development of broilers

This experiment was conducted to investigate the effect of Bacillus and antibiotics on growth performance,immune indices and intestine development of broilers.Nine hundred 1-day-old roosters were randomly divided into 3groups with 10 replicates of 30 each.The control group was fed basal diet and the others were fed basal diets supplemented with antibiotics(100 g/t)and Bacillus HB1(300 g/t) respectively.The experimental period was 36 days.The results showed as follows:(1)The average daily gain(ADG) of broilers fed basal diet added with Bacillus HB1 was increased,compared with the control group(P 0.05).And during the period of 22 ~ 35 days,feed conversion rate(FCR) of treatment 2 was 2.66% lower than that of control group(P 0.05).(2)Compared with the control group,the content of Ig G in Bacillus HB1 adding group was significantly increased by 226 percent(P 0.05),as well as the development of thymus was also improved.(3)Adding Bacillus HB1 significantly increased villus length/crypt depth(V/C)value in duodenum(P 0.05),jejunum(P 0.05) and Bacillus ileum of broilers(P 0.01).In conclusion,Bacillus could improve broilers growth performance,immunity function and intestinal development.