Unravel The Difference In Gut Microbiota And Milk Metabolite And Their Regulation On Reproduction And Lactation Performance Of Sows

The reproductive and lactation performance of sows is the key factor that determines the production and economic benefit of pig industry.Previous studies reported that gut microbiota and milk functional molecules play an important regulatory role in metabolize of maternal and growth of offspring.But the effect of gut microbiota and functional milk molecules on reproduction and lactation performance of sows has not been reported.The aim of this research is to investigate the difference in gut microbiota and milk metabolites in sows with different stillbirth rate and lactation performance,and elucidate the mechanistic about gut microbiota or milk composition regulates the reproduction performance of sows.In total,168 multiparity Yorkshire sows were included in the study,the model of sows with different stillbirth rate and lactation performance based the stillbirth rate and litter weight of piglets.Experiment 1.20 sows were divided separately into a high stillbirth group(stillbirth rate > 11.11%)and a low stillbirth group(stillbirth rate < 11.11%)according to parity,average piglet weight and total born piglet number.The performance,oxidative stress status and structure of the gut microbiota of sows were analyzed.The results showed that the low group had a shorter farrowing(P<0.05)as well as higher concentration of serum total antioxidant capacity and hydroxyl radical scavenging capacity(P < 0.05).The gut microbiota composition of the tested sows,6 genera differed between the two groups(P<0.05),7 genera were correlative with stillbirth rate(P<0.05),and 2 genera were correlated with farrowing duration(P<0.05).The relative abundance of Lachnospiraceae＿UCG-001,Marvinbryantia and Ruminococcaceae＿UCG-004 were negatively correlated with antioxidant capacity(P<0.05),but positively correlated with the stillbirth rate of sows(P<0.05).Furthermore,the microbiota functions in the polyketide sugar unit biosynthesis(P<0.05)and nitrotoluene degradation(P<0.05)were found to be different between the two groups by phylotypic investigation of communities by reconstruction of unobserved states analysis.Experiment 2.66 sows were divided separately into a high lactation performance group(H,weaning weight >57.01kg)and a low lactation performance group(L,weaning weight <46.15kg)according to parity,backfat thickness and the number of piglets,litter weight,average birth weight of piglets after cross-foster.The litter performance,milk metabolites,oxidative stress status and gut microbiota composition of sows were analyzed.The result showed that the oxidative stress was higher in L group at farrowing(P < 0.05).The concentration of lactose in the milk is lower in the L group(P<0.05).The carbohydrate metabolites and amino acid metabolite in the milk were significant different between two groups(P<0.05),there were 13 carbohydrate metabolites(P<0.05)and 12 amino acid metabolites(P<0.05)were significant different between two groups,respectively.16S r RNA sequencing were used to detected the difference between high or low lactation performance sows.The result showed that there were 12 genera in the gestation(P<0.05)and 13 genera in the duration(P<0.05)were identify as marker for distinguishing the sows with different lactation performance.The relative abundance of Cyanobacteria in gut microbiota(P < 0.05)and the mannitol in milk(P < 0.05),which is a marker of Cyanobacteria,was higher in the L group.The creatine in the milk,which could contribute to the recovery of the damaged brain tissue of sucking offspring,was higher in the H group(P<0.05).The total antioxidant capacity and litter weight of sows at weaning were positive correlation with the relative abundance of Bacteroides＿f＿＿Bacteroidaceae(P<0.05)and negative correlation with the relative abundance of Phascolarctobacterium and Streptococcus(P<0.05).In summary,the prolong of farrowing duration in high stillbirth rate sows was closely related to the disorders of gut microbiota.The milk functional molecules and gut microbiota composition were key regulatory targets to determine the lactation performance of sows.