Effects On Growth Performance,nutrient Digestion And Fecal Microbes In Ningxiang Pigs By Transplanting Fecal Microbiota From Duroc×Landrace×Yorkshire Pigs

As one of the important local pig breeds in our country,Ningxiang pigs(NXP)have excellent characteristics of tender meat and delicious flavor;however,its slow growth rate and the low feed remuneration seriously restricts the breeding economy benefit.Recent studies have shown that fecal microbiota transplantation(FMT)may be an effective technique to improve the growth performance and gut microbiome of recipient animals.The purpose of this study was to investigate the effect on growth performance and other indicators of NXP by fecal microbiota transplantation from Duroc×Landrace×Yorkshire pigs(DLY),and to preliminarily reveal its rules through analyzing serum metabolomics and fecal microbes.The experiment adopted a completely randomized design.Thirty-six healthy Ningxiang boars weighing about 20 kg were selected and randomly divided into 2 groups,the control group(NXP＿CON)and the FMT recipient group(NXP＿FMT),with 3 replicates in each group and 6 NXP in each replicate.Six DLY with similar body weight to NXP were selected as the fecal microbiota donor group.All pigs are fed the same diet,the prefeeding period was 7 days,and the formal period lasted for 28 days.During the formal period,fresh feces were collected daily from DLY to make fecal microbiota suspension,and transplanted to NXP＿FMT.The feces were collected continuously 3 days before the end of the experiment.At the end of the experiment,all NXP were weighed on an empty stomach,and feces and blood samples were collected.The growth performance,apparent digestibility of nutrients,serum biochemical indexes,serum metabolomics and fecal microbial composition of NXP were analyzed.The test results are as follows:1)Compared with the NXP＿CON group,the average daily gain of NXP＿FMT group increased significantly(P<0.05);2)Compared with the NXP＿CON group,the digestibility of crude fiber,Ca and P of NXP＿FMT group were significantly increased(P < 0.05),and the digestibility of crude protein and ether extract showed an increasing trend(P=0.083).3)Compared with the NXP＿CON group,the serum LDL-C content in the NXP＿FMT group was significantly decreased(P < 0.05);the GLB and TP content was significantly increased(P<0.05).4)Compared with the NXP＿CON group,there were significant differences in serum metabolomics of NXP＿FMT group.The differential metabolites were mainly involved in amino acid metabolism,lipid metabolism and digestive system-related metabolic pathways.7 differential metabolites were related to amino acid metabolism;6 differential metabolites were associated with lipid metabolism;and 4 differential metabolites were associated with digestive system.5)Compared with the NXP＿CON group,the Ace index and Chao1 index of NXP＿FMT group were significantly decreased(P <0.05),the Sobs index showed a downward trend(P=0.058),suggesting that FMT might change the diversity of the fecal microbial community of NXP.FMT significantly increased the abundances of 5 bacterial genera including Terrisporobacter,Blautia,Agathobacter,Faecalibacterium and Escherichia-Shigella in NXP’s feces.The abundances of Lachnospiraceae＿XPB1014＿group and Treponema decreased significantly.In conclusion,FMT from DLY to NXP could improve the growth performance and apparent nutrient digestibility of NXP,and its mechanism might be related to the regulation of FMT on fecal flora and amino acid metabolism,lipid metabolism and digestive system-related metabolic pathways.