The Dynamic Influence Of Probiotics On The Growth Performance And Gut Microbiota Of Wuliangshan Black-bone Chickens

Wuliangshan black-bone chicken is one of the most famous local chicken breeds of Yunnan and one of the key agricultural products in the development of Yunnan plateau-characteristic agriculture.Relevant studies have shown that the intestinal microbiota plays an important role in the feed digestion,nutrient absorption and pathogen resistance of chickens,and the early stage after hatching is a key established stage of intestinal microbiota in the chicken intestine.Based on one-way ANOVA analysis using SPSS statistic software,this experiment measured the growth capacity,the immune indexes with traditional measuring methods,measured the activity of anti-oxidant enzymes with kits.This experiment measured the microbiota in different intestine parts（duodenum,jejunum,cecum,ileum and rectum）of Wuliangshan black-bone chickens at 9 time points of brooding stage(1^st42ⁿdd day)with high-throughput Miseq sequencing technology.Finally,this experiment tries to research the relationship between microbiota and growth capacity etc.indexes,and then provide some basic theory for selection of intestinal probiotics and promotion of healthy development of chickens.This experiment divided 180 Wuliangshan black-bone chickens into 3 groups evenly and randomly,and measured the growth capacity,immune organ indexes,anti-oxidant enzyme activities and dynamic change of microbiota under three different feeding conditions,which is added with Enrofloxacin（antibiotic group）,probiotic liquid（probiotic group）and clean water（control group）separately into the drinking water during the brooding period(1^stto 42^ndday).It is shown that,for the Average daily gain（ADG）,the most significant difference appears during 35^thh to 42ⁿdd day,in which the ADG of probiotic group is 26.31%higher than that of the control group（p<0.05）and the ADG of antibiotic group is 52.65%higher than that of control group（p<0.01）.Thus it could be seen that both the usage of probiotics and the antibiotic promoted the increase of body weight of chickens,while the promotion of the antibiotic is more significant.It is shown that,for the Ratio of Feed to Gain（F/G）,the most significant difference appears during 35^thh to 42ⁿdd day,in which the F/G ratio of the antibiotic group is the lowest（2.803）,the F/G ratio of the probiotic group is in medium（3.416）,while that of control group is the highest（4.397）.Therefore,the antibiotic group is better than the probiotic group,while the probiotic group is better than the control group in terms of F/G ratio.It is shown that,for the genus level,Lactobacillus,Pseudomonas,Bacteroides,Enterococcus and Ruminococcus are dominant microbiotas.It is shown that,from 1^stt day to 42ⁿdd day,the average ratios of Lactobacillus in cecum,duodenum,rectum and jejunum of the probiotic group are higher than the corresponding ratios of the other two groups;from 1^stday to 42^ndday,the average ratios of Bacillus in cecum,duodenum,rectum and jejunum of the probiotic group are higher than the corresponding ratios of the other two groups.It is shown that,Ruminococcus and Bacillus may be relevant to the Average daily gain（ADG）and Ratio of feed to gain（F/G）.It is shown that the microbial diversity of cecum is relatively high in the three groups on 28^thh day or 35^thh day;the total abundance of the three groups is 1816 OTUs till the 42ⁿdd day;to some extent the probiotics we used could inhibit the Actinobacteria;the probiotic group is better than the antibiotic group in terms of the inhibition effect on Elizabethkingia.In conclusion,compared to the antibiotic group,the probiotic group is better in increasing the T-SOD level of liver,promoting the microbiota diversity of rectum,increasing the ratio of Lactobacillus and Bacillus in different parts and inhibiting the growth of Elizabethkingia,thus more beneficial to the health of chickens.