Effects Of Fermentation To Hydrolyze Protein On Growth Performance And Changes Of The Intestinal Microflora Of Broiler Chicken

For studying conditions of Bacillus subtilis producing enzyme activity and adding exogenous enzymatic to hydrolyze protein.The effects of compound small peptide additive on the growth performance of the broiler chicken were investigated in the trial.Using PCR-DGGE to detect the changes in the broiler intestinal flora.In present study,we used a bacillus strain which was isolated and preserved by Animal Microecology Laboratory.The bacillus strain was identified as Bacillus subtilis by 16S rRNA method.For studying the optimal conditions of Bacillus subtilis producing enzyme activity, we used Folin-Phenol method to measure the main condition(temperature,initial pH,culture time,inoculum size) which could influence it.According to the results of four three-level orthogonal factor test,the optimal conditions for producing enzyme were:temperature at 30℃, the initial pH 7.5,culture time 18h,1%value of inoculum.Using Bacillus subtilis and exogenous proteinase,and optimizing the conditions for foreign-enzyme(Alcalase amount,flavourzyme amount,fermentation pH,fermentation time), according to single-factor result,we designed a four three-level orthogonal factor test for finding the optimal enzyrnolysis conditions.The results showed the optimal conditions were: the adding value 0.016AU/g of Alcalase protease,the adding value 25LAPU/g of flavourzyme, the temperature of enzymolysis 60℃,the enzymolysis time 5h.The production of enzymolysis contained 67.53%of small peptide,15.47%of amino nitrogen,the degree of hydrolysis 27.65%,the number of live Bacillus subtilis 1.825×10~8 CFU/g.The compound small peptide additive was added into the broiler chicken Diet as the dosage of 1.2%,0.8%,0.5%,and 0.3%.Then the production performance was detected.The results showed that,compared to the control group,the weight increased 31.04%in 0.8%test group,the difference was extremely significant(P＜0.01);feed conversion ratio reduced 17.29%,the difference was significant(P＜0.05);diarrhea rate was decreased 5.95%,the difference was extremely significant(P＜0.01).The results showed that the test 1 group and the control group weight gain were significant(P＜0.05);feed conversion was significant(P＜0.05);diarrhea rate was extremely significant(P＜0.01).The weight gain and feed conversion were changed in the test 3,4 group and the control group the difference was not significant(P＞0.05);diarrhea rate was extremely significant(P＜0.01).The best production performance test group 0.8%was chosen to analyze the changes and diversity of bacterial population in the intestines and compare to the control group.The results showed the number of bacterial population of was low and ruleless.The results showed the similarity of bacterial population at third week was rising and the diversity was increasing.At the sixth week,the number of bacterial population of test group increasing 18%and the specific band was showed up.We could infer from these results that compound small peptide could maintain the balance and increasing the diversity of bacterial population in the intestines.