Effects Of Dietary Bacillus Licheniformis On Growth Performance,Antioxidant Function And Cecal Microfloraof Broilers

With the continuous in-depth research on probiotics,there is increasing research on the characteristics and various applications of Bacillus licheniformis at home and abroad.Bacillus licheniformis is widely used as a competitive inhibitor of probiotics or pathogenic bacteria in livestock and poultry industry because of its high temperature resistance,acid and alkali resistance,strong stress resistance and easy storage.The purpose of this paper is to study the effects of adding Bacillus to the broiler’s growth performance,slaughter performance,blood index,anti-oxidation,intestinal tissue morphology and cecal microflora,and to explore the optimal recommended dosage of Bacillus licheniformis in broiler production.To provide a theoretical basis for its further promotion and application.728 1-day-old healthy AA broiler male chicks were selected and randomly divided into 8 groups,each with 7 replicates,each with 13 chickens.Divided into control group(basic diet)and experimental group(basic diet with 80mg/kg,200 mg/kg,400 mg/kg,700 mg/kg Bacillus licheniformis,250 mg/kg zinc bacitracin,250 mg/kg zinc bacitracin + 200 mg/kg Bacillus licheniformis).The experiment lasted for 42 days,divided into two stages,0-21 days old,22-42 days old,and were fed different diets.The results showed that:The 21-day average body weight of the 1.80mg/kg Bacillus licheniformis group was 1119.10g,which was significantly higher than that of the 400mg/kg Bacillus licheniformis group(P<0.05).The daily weight gain of the 80mg/kg Bacillus licheniformis group from 1 to 21 days was significantly higher than that of the 400mg/kg Bacillus licheniformis group and the mixed group of Bacillus licheniformis and bacitracin zinc(P<0.05).The average daily feed intake of the 80mg/kg Bacillus licheniformis group and the 200mg/kg Bacillus licheniformis group was significantly higher than that of the 400mg/kg Bacillus licheniformis group(P<0.05).The feed-to-body ratio of the bacitracin zinc group and the mixed group of Bacillus licheniformis and zinc bacitracin was significantly higher than that of the control group(P<0.05).The average body weight of the 80mg/kg Bacillus licheniformis group was 3205.40g for 42 days,which was significantly higher than the mixed group(P<0.05).The daily weight gain of the 80mg/kg Bacillus licheniformis group was 75.33g during 1-42 days,which was significantly higher than the bacitracin zinc group(P<0.05).The death rate of 200mg/kg and 750mg/kg Bacillus licheniformis was zero,and the EPI value was significantly higher than that of the control group and 400mg/kg Bacillus licheniformis group(P<0.05).2.There was no significant difference in IgA,IgG and IgM content among the Chlamydomonas group,the bacitracin zinc group and the mixed group(P>0.05).The serum GSH of the 400mg/kg Bacillus licheniformis group was significantly higher than that of the other groups(P<0.05).There were no significant differences in serum MDA content,GS,GSH-Px,CAT and SOD activities among the Chlamydomonas group,the bacitracin zinc group and the mixed group(P>0.05).There were no significant differences in liver MDA,GSH content,GS,GSH-Px,CAT and SOD activities between the Chlamydomonas group,the bacitracin zinc group and the mixed group(P>0.05).3.The slaughter rate of 200mg/kg Bacillus licheniformis group was significantly higher than that of 80mg/kg Bacillus licheniformis group(P<0.05).There was no significant difference in breast muscle rate and wing rate among the Chlamydomonas group,the bacitracin zinc group and the mixed group(P>0.05).The leg muscle rate of the 750mg/kg Bacillus licheniformis group was significantly lower than that of the 400mg/kg Bacillus licheniformis group and the mixed group(P<0.05).The abdominal fat rate of the control group,750mg/kg Bacillus licheniformis group and mixed group was significantly higher than that of 400mg/kg Bacillus licheniformis group(P<0.05).The hydraulic power of the 750mg/kg Bacillus licheniformis group and the 250mg/kg bacitracin zinc group is the highest,which is significantly higher than the control group,80mg/kg Bacillus licheniformis group,400mg/kg Bacillus licheniformis group and mixed group(P<0.05).The flesh color redness value of the 80mg/kg Bacillus licheniformis group was the highest,which was significantly higher than the other groups(P<0.05).4.The height of duodenal villi in the 750mg/kg Bacillus licheniformis group was the highest,which was significantly higher than that of the control group and the 400mg/kg Bacillus licheniformis group(P<0.05).The ileal crypt depth of the 750mg/kg Bacillus licheniformis group was significantly higher than that of the 80mg/kg Bacillus licheniformis group and the bacitracin zinc group(P<0.05),200mg/kg Bacillus licheniformis group,400mg/kg lichen The depth of intestinal crypts in the bacillus group was significantly higher than the bacitracin zinc group(P<0.05).The relative abundance of Stenotrophomonas in the 750mg/kg Bacillus licheniformis group was significantly higher than that of the 200mg/kg,400 mg/kg Bacillus licheniformis group and the bacitracin zinc group(P<0.05).The relative abundance of Lactobacillus in 400mg/kg Bacillus licheniformis group and Bacitracin zinc group was significantly higher than that of 80mg/kg lichen group,750mg/kg lichen group and mixed group(P<0.05).The relative abundance of Faecalibacterium in the mixed group was significantly higher than that of the 750 mg/kg lichen group(P<0.05)The growth of broilers and increase the height of duodenal villi and the depth of duodenal recess.The addition of 80mg/kg Bacillus is more effective,750mg/kg Bacillus licheniformis can improve the microbial diversity of the cecum;adding Bacillus or bacitracin zinc to the diet can promote broilers growth and development,improve the intestinal environment,but the combined effect of the two is not better than the effect of Bacillus alone.In summary,adding Bacillus to the diet can promote the growth of broilers to some extent,reduce the mortality of broilers and increase the EPI value,and improve the height of duodenal villus and the depth of cloaca,and improve the water binding rate and brightness of muscle,furthermore improve the microbial diversity of cecum.