Effect Of Fish Oil Supplementation On Sow Reproductive Performance,Immune Function And Fecal Flora In Late Pregnancy And Lactation

In animal husbandry production,females postpartum estrus recovery is strictly determined by the endocrine status of females,delay estrous or not estrous will reduce the production performance of female animals.For breeding farms,multiparous sows delayed estrus after weaning that will prolong the non-productive days of sows,reduce the annual number of weaned piglets in sows.Through nutritional intervention for sows in late pregnancy and lactation,the endocrine hormones can be effectively regulated,promote the sows to quickly enter the estrous period after weaning,and effectively improve the utilization efficiency of breeding sows.The purpose of this experiment is to study the effect of different doses of fish oil in late pregnancy and lactating sows on estrus recovery,immune function and fecal flora,and explore the application effect of fish oil in sow production.In the experiment,45 healthy Yorkshire × Landrace first fetal sows were selected and randomly divided into three groups:control,low-dose group(30g/d)and high-dose group(60g/d).Each treatment was 15 sows.The experiment began on day 90 of pregnancy and the end of lactation day 21(weaning),all sows were kept under consistent management conditions.The effect of fish oil on the sow reproductive performance,immune index and fecal microbial microflora were analyzed,and the main results are as follows:1.Daily diet was added in late gestation and lactating sows with fish oil,significantly increased EPA and DHA content in sow serum and colostrum.There was no significant effect on feed intake,body weight,and backfat loss in sows.It will not adversely affect the total number of piglets,live piglets,initial weight of piglets and labor process of sows.Fish oil had also no significant effect on colostrum composition in sows.Laclactation power of sows was significantly improved(P<0.05).There is a tendency to increased in lactation volume(0.05≤P< 0.10).Fish oil can shorten the weaning estrus interval of sows by about 1.7d,and the difference reaches a significant level(P<0.05).The serum concentrations of Estradiol、Prolactin and Prostaglandin E2 significantly increased in 60g/d fish oil group(P<0.05).2.Daily diet was added in late gestation and lactating sows with fish oil,there was no significant difference in the conventional serum biochemical indexes of sows.Compared with the control group,the serum Ig A concentration was significantly increased in the 60g/d fish oil supplemented group(P<0.05),Ig G and Ig M concentrations tended to increase(0.05≤P <0.10).Fish oil has significantly increased serum Malondialdehyde content and Superoxide Dismutase and Catalase vitality(P<0.05).Serum Glutathione Peroxidase vitality significantly increased and serum Cortisol concentration significantly decreased in 30g/d fish oil group(P<0.05).3.Daily diet was added in late gestation and lactating sows with fish oil,the serum zonulin expression of sows in the 60g/d fish oil group was significantly lower than that in the control group(P <0.05).Analysised of 16 S r RNA sequencing of sow fecal bacteria found that the microbial Simpson index of fish oil supplementation was significantly higher than that of the control group(P<0.05).The addition of fish oil significantly increased the abundance of the Lactobacillus(P<0.05),and the relative abundance of Ruminococcaceae＿UCG-014 was significantly higher in the 30g/d fish oil-added group than in the control group(P<0.05).Analytical correlation findings,Lactobacillus showed a significant positive correlation with serum Estradiol and Prolactin concentrations(P<0.05),and Ruminococcaceae＿UCG-014 also showed a significant positive correlation with serum Estradiol and Prostaglandin E2concentration(P <0.05).The above results shown that fish oil supplementation in late pregnancy and lactation can shorten the emitotic interval of weaning.It improved the immunity and stress resistance,regulates the gut microbiota structure in sows,and improved the health of sows.The daily addition of 60g/d is more beneficial for the health and production of sows.This study provides a reference for the application of adding different doses of fish oil in the regulation of reproductive performance in sows.