The Polymorphism Of Intestinal Microbe In Yunan Black Pigs And "Duroc×large White×Landrace" Three Breed Hybrid Pigs

As a symbiotic bacteria,intestinal microorganisms were closely related to the health of animals,and played an important role in promoting digestion and absorption,enhancing immunity and resisting pathogenic microorganisms.Pig quality was an important indicator of the pig industry.In this study,using high-throughput sequencing and PCR-DGGE gradient electrophoresis technology focused on two different varieties of pig,Three breed hybrid pigs and Yunan black pigs,explored the intestinal microflora and the proportions of the diversity characteristics,to find the relationship of intestinal microflora structure and pigs among different varieties.In order to understand the intestinal microbial differences of two pig breeds,to provide new ideas and directions for further reveal of the influence of gut microbes in the pig body and pig breeds improvement and optimization.Experiment 1: The diversity of bacterial flora in different intestinal segments This experiment analyzed the difference of intestinal bacterial community structure between jejunum,ileum,colon and cecum from three hybrid pig and Yunan black pig by using PCR-DGGE technology combined with similarity analysis method,and analyzed the dynamic changes of the intestinal bacterial community in different age of days(including the conservation period and the fattening period)on the time axis,attempt to reveal the changes and differences of intestinal microflora during varieties of ages and cultivars.The results show that: 1)Yunan black pig jejunum DGGE of differential bands could be identified respectively 23.00±0.6 in fattening pigs,23.00±0.6 in piglets,three yuan hybrid pig 21.67±0.3 in fattening pigs,14.33±2.6 in piglets.2)three yuan of hybrid pig ileum DGGE of differential bands were identified respectively 22.67±0.3 in fattening pigs,16.33±2.3 in piglets,Yunan black pig were 23.67±0.3 in fattening pigs,23.67±0.9 in piglets.3)Yunan black pig colon DGGE of differential bands were identified respectively 23.67±0.9 in fattening pigs,25.00±0.0 in piglets,three yuan hybrid pig 23.33±1.8 in fattening pigs,19.00±1.5 in piglets.4)Yunan black pig cecal DGGE fingerprint can identify bands respectively 25.00±0.6 in fattening pigs,22.00±0.6 in piglets,three yuan hybrid pig 24.67±0.9 in fattening pigs,22.00±1.0 in piglets.With the intestinal structure from near to far,dominant bands of DGGE gradually increased,intestinal microflora of fattening period was slightly more than piglets,the similarity results of jejunum,colon and cecum were the same that the intestinal microbial community structure diversity was maximum in corresponding section of intestine in different varieties of piglets.The results suggested that intestinal bacterial community structure changed with different age stages,while the corresponding variation tendency of different intestinal sections were not the same,and the main regular pattern was that the structure of intestinal flora were abundant in the nursing period.With the increase of age,the structure tended to be single.Based on the above,we speculated that there was a correlation between the composition of the intestinal microflora and the cultivated varieties of pigs.Experiment 2: The characteristics of intestinal microflora in different pig breeds The research applied high-throughput sequencing and bioinformatics analysis technology to research microbial diversity in contents of small intestine and big intestine from "Duroc×large white×Landrace" three hybrid pig and Yunan black pig,analyzed microbial community differences associated with genetic characteristics of pigs.The results showed that 208737 sequences were obtained effectively,high-quality sequences for the highest percentage of sample BB,reached 98.04%;the lowest for the sample BS,only 93.96% species;the average of each sample of 46863 valid sequences,43888 high quality sequences,2971 specific sequences,1018 OTUs;group BB group WS the highest species abundance,species richness the lowest species abundance high two pig large intestine samples,good uniformity;group BB high evenness,diversity was higher in BS group,the highest abundance of flora;microbial species in small intestine in three yuan more,the hybrid pig intestine microbial species were the least.Species mainly including Firmicutes,Bacteroidetes,Proteobacteria and Tenericutes,the total proportion of these four strains was as high as 97.94%,but the proportion of these 4 dominant bacteria in each group was different.At the level of phyla,Firmicutes was absolutely dominant bacteria in the three groups,except for WS group;in the two large intestine groups,Bacteroidetes took the second dominant bacteria;at genus level,Lactobacillus sp.was the main bacteria in BS group and significantly higher than the other 3 groups.PCA detection showed that there were differences in intestinal microbial diversity in different breeds of pigs.Phylogenetic analysis showed that the Firmicutes mainly existed in three hybrid pig small intestine,Bacteroides mainly existed in three hybrid pig big intestine,Lachnospira mainly existed in Yunan black pig small intestine,Lactobacillus mainly existed in Yunan black pig large intestine.The results showed that the different intestinal environment might lead to the migration of microbial flora.