Identification And Analysis Of Gut Microbes Affecting Semen Quality And Sexual Behavior In Breeding Ducks

It is very important to improve the reproductive performance of male ducks for improving the breeding efficiency of high-quality meat ducks and reducing the cost of breeding ducks.Many studies have shown that gut microbes or beneficial bacteria affect the growth,development and production performance of the host,but there is no report that gut microbes affect the semen quality of breeding birds in poultry.In this study,the sexually mature Wuqin 10 meat duck supporting line male duck population was used as the experimental object,and the genera associated with semen quality and reproductive physiological indicators were screened by gut microbial sequencing to provide a basis for the screening of beneficial bacteria that can be used to improve the semen quality of breeding ducks.This research mainly results are as follows:1.The population of male ducks was divided into sexually sensitive and insensitive groups(DN)by the lure stimulation method.The semen quality of the sexually sensitive individuals was high(DH)and low(DL).The measurement and statistical results showed that the sperm motility and sperm motility rate of the DH group were significantly higher than those of the DL group(p<0.001),and the sperm deformity rate was significantly lower than that of the DL group(p<0.0001).Compared with DN group,the proportion of normal testicular lumen was significantly higher in DH and DL groups(p<0.001),and the thickness of testicular lumen seminiferous epithelium in DH group was significantly higher than that in DL group(p<0.001).2.The measurement results of serum biochemical indexes of different groups of male ducks showed that the contents of blood glucose,Gn RH,LH,FSH and T levels were significantly higher in the DH group than in the DL group,while TNF-α in the DL group and IL-1β in the DN group levels were significantly higher than in the DH group(p<0.01,p<0.05).The correlation analysis results of serum biochemical indexes and semen parameters showed that the contents of T,LH and Gn RH were significantly positively correlated with sperm motility rate,blood glucose was significantly negatively correlated with sperm abnormality rate,and IL-1β was significantly positively correlated with sperm abnormality rate.3.The intestinal morphology of male ducks of different fecundity groups was analyzed by HE staining.DH group of duodenum,jejunum and ileum villus height and crypt depth ratio was significantly higher than that of DL and DN group(p<0.01),DH group had a significantly higher muscle layer thickness of the cecum DL and DN group(p < 0.01).Through PAS staining and toluidine blue staining,it was found that the content of goblet cells in the duodenum of the DH group was significantly higher than that of the DL and DN groups(p < 0.01),and the content of goblet cells in the jejunum and ileum in the DH and DL groups was significantly higher than that in the DN group(p < 0.01).Its number was significantly lower than that of the DH group and the DL group.4.Through the sequencing and analysis of gut microbes,it was found that the dominant and secondary bacterial phyla in the duodenum,jejunum,ileum and rectum of the three groups of DH,DL and DN were Proteobacteria and Firmicutes,the dominant bacteria in the cecum are Bacteroidetes and Firmicutes;The dominant genus in duodenum,jejunum,ileum and rectum is Pseudomonas,and the dominant genus in cecum is Bacteroides.The microbes of each intestinal segment of drakes in different fecundity groups were significantly different at the genus level.For example,in the jejunum,Enterococcus was significantly enriched in DH group,Ruminococcus was significantly enriched in DL group,and Helicobacter and Bacteroides was significantly enriched in DN group,etc.5.Correlation analysis found that the microbes in each intestinal segment had consistent correlations with individual semen quality and serum biochemical indicators.In general,Bacillus,Enterococcus,Leucobacter,Bifidobacterium,Prevotella and Mycobacterium spp.were significantly positively associated with semen quality.Alistipes was significantly positively correlated with reproductive hormones and significantly negatively correlated with pro-inflammatory factors;Helicobacter,Oscillospira,Ruminococcus and Streptobacter were significantly negatively correlated with semen quality Streptobacillus,Clostridium,Blautia and Ochrobactrum were significantly negatively correlated with reproductive hormones and significantly positively correlated with pro-inflammatory factors.From the above results show that the morphological development of testis is closely related to spermatogenesis and semen quality.Intestinal microorganisms such as Lactobacillus,Bacillus,Bifidobacterium and Prevotella can improve the intestinal morphology and are beneficial to the improvement of intestinal barrier function.It can maintain the reproductive hormones in the body at a certain level,which is conducive to the occurrence of sperm;and the harmful bacteria represented by Helicobacter,Oscillobacter and Ruminococcus can reduce the reproductive hormones in the male duck and the energy required for sperm movement.Promoting the production of inflammatory factors affected normal spermatogenesis,and combined with the accumulation of metabolites disrupted signaling in the nervous system,reducing the sexual sensitivity of male ducks.