Association Analysis Between Intestinal Microbiota With Egg Laying Levels In Hens

Gut microflora as commensal microorganims exert a critical influence on host health ranging from animal digestion 、 immunity to disease resistance.Egg laying levels is an importance index which usually be used to reflect the hens health state.The study aimed to explore the intestinal microbial diversity and the relationship between intestinal microflora with different levels of laying hens during their egg-laying peak period.Experiment 1: Intestinal microbial diversity and the relationship with egg laying levels in hensHigh-throughput sequencing of V4~V5 variable regions of 16 S r RNA genes was utilized to detect the composition and distribution of microbes in the fecal samples among three levels of egg laying hens(n=6:6:3).As a result,the structure of intestinal microflora in different levels of egg laying hens were significant differences.There was a certain similarity between H group and L group,but there was a significant difference with VL.The major species of bacteria were Firmicutes,Bacteroidetes,Actinobacteria,Proteobacteria and they account for 99% of the total.However,the proportion of the four bacterial communities in three levels were obviously different.In bacterialphyla,the fecal microbiota was largely dominated by Firmicutes(over70%);and then the second was Bacteroidetes(L exception).On the bacterial genus level,the abundance of Lactobacillus in the H group(66.05%)was three times higher than that in the VL group(20.93%).The results of PCo A analysis showed that the microbial community structure in fecal samples of three egg laying levels of were different apparently.The analysis of KEGG demonstrated that the functional genes were mainly enriched in membrane transport pathway,amino acid metabolism and carbohydrate metabolism pathway,especially in VL group.As a results,the above supported the relationship between intestinal microbial and production levels in hens during egg-laying peak period.The gut dysbacteriosis may be one of the reasons for low production levels in laying hens.For the lower egg laying rate hens,their environment for microbiota growth in the intestine were destroyed,and the intestinal microbiota had to compensatorily adapt to the changed intestinal micro-environment.Experiment 2: Effects of fecal microbiota transplantation on the re-establishment of intestinal microflora and performance in different levels of laying hensFecal microbiota transplantation(FMT)in gut dysbacteriosis was a promising therapy,despite some adverse side effects.In this study,the fecal microflora structure were detected post-treatment with antibiotic in fecal transplant recipients(FMT)and the spontaneous recovery groups using PCR-DGGE technology.Forty 190-day-old hyline brown laying hens were selected and divided into 2groups according to their egg laying levels(>96% VS 30%~60%).Every group included fecal transplantation group(n=10)and spontaneous recovery group(n=10).Fecal microbiota transplanted to each other between two groups.Experimental animals were administered with antibiotic intra-gastrically for 3 days to disturb the stable flora.Thereafter,FMT were performed on antibiotic-treated hens for 3consecutive weeks to rebuild the intestinal ecosystem.PCR-DGGE was applied to detect dynamic variation of fecal microbiota structure in the four groups at different time points.We attempt to demonstrate the change and difference of microflora between pre and post-FMT.The results showed that:(1)After 2 weeks of recovery,increasing the dominant bands and Shannon index were observed in the HSR group.(2)The dominant bands were gradually increased,not changing significantly the patterns of microbial diversity were observed in the HFMT group.But the Shannon index decreased after 2 weeks of transplantation,and began to rise until third weeks in the HFMT whose egg production rate was significantly lower(P<0.05).(3)After 2 weeks of recovery,the patterns of microbial diversity that had recovered(defined as having no significant difference compared with pre-administration)in the LSR group.By the third week,there was no significant difference in the microbial diversity compared with antibiotic-induced.(4)Comparing with pre-administration,the number of dominant bands of transplantation after 2 weeks increased,the microbial diversity of transplantation after 3 weeks was increased in the LFMT group(P<0.05).The above results suggested that: after the short antibiotic treatment,no significant changes in the structure of the intestinal microflora were observed in the H group.But the intestinal microbial abundance decreased in the L group,it was not fully recovered even until 21 d.The results supported that FMT promote the re-establishment of intestinal microbial communities in L group hens with antibiotic-induced dysbiosis,and also contribute to the egg laying level.FMT had little effect on intestinalmicrobial communities of H group hens,but the rate of egg production was significantly lower(P<0.05).Intestinal microbiota of high yield of egg laying hens maintains intestinal homeostasis balance;low yield of egg laying hens exits the imbalance of bacteria phenomenon in intestinal.In conclusion,we speculated that there is a correlation between the composition of the intestinal flora and the egg production,and the correlation may be performed by intestinal flora and its metabolites.