Study On Physical And Chemical Characteristics Of Bacillus Licheniformis And Effect Of It On Performance Of Laying Hens

In this study,the stress resistance and characteristics of Bacillus licheniformis were evaluated through the vitro trials. The mechanism of the effect of B.licheniformis on layer performance were studied by feeding experiment. Results were as follow. Study on stress resistance and probiotic characteristics of Bacillus licheniformis in vitro.The stress resistance and characteristics of Bacillus licheniformis were investigated . Five trials were conducted to evaluate the thermostability, acid and bile tolerance, antibacterial activity and the adhesion properties of Bacillus licheniformis . The trial results were as follows: Viable cell counts of B. licheniformis showed no notable difference in the pelleting process(P>0.05). The viable count of the high-temperature treatment group for 5 and 7.5 min was 0.63%(P>0.05), 1.26%(P >0.05) less than that for 2.5 min. The viable count in the high-temperature treatment group for 2.5 min was 2.25% higher than that of the control(P>0.05). In the acid tolerance trial, the viable count in the treatment group increased by 0.77%(P>0.05), 1.54%(P>0.05), and 1.34%(P >0.05) respectively for pH 2, 3and 4 gastric fluid treatment groups compared with that of the control. In the bile salt treatment, the viable counts of B. licheniformis was 2.06% less than in the control(P<0.05). The bacteriostasis circle of B. licheniformis culture to Bacillus coli and Staphylococcus aureus was 0 and 16.16 mm respectively. In the adhesion trial, the number of adhesive B. licheniformis to the intestinal epithelia was 27 cfu/100 cell. These results indicated that the pelleting process and artificial stomach juice have no affect on B. licheniformis viable counts.The B. licheniformis have strongly inhibit capability to Staphylococcus Aureu.The B. licheniformis can not plant in layer digestive tract permanently.Research on the mechinsm of B. licheniformis on the performance of laying hens. Different number of B.licheniformis were added to layer diets at different level.The effects of B.licheniformis were assessed through performance,egg quality, serum biochemical index, Intestinal flora, Intestinal morphology. The results showed that (1)B. licheniformis has no affected on average egg weight, laying percent,daily feed intake and FCR(P>0.05).(2) B. licheniformis decreased cholesterol content in eggs(P>0.05).(3) B. licheniformis improved the immunity of laying hens (P>0.05). (4)Adding B. licheniformis decreased the number of E. coli and increased the number of Lactobacillus and Bifidobacterium in layer ileum content(P>0.05).(5) The effect of adding B. licheniformis increased the Villous Height and V/C while reduced the Mucosal Thickness in the layer duodenum and jejunum(P>0.05). In this experiment , B. licheniformis has no affected on product performance and has improvement trendency on egg quality, immunization performance, intestinal flora, intestinal morphology.