Mechanism And Effects Of Grape Pomace On The Songliao Black Weaned Piglets

Grape pomace(GP)is the main by-product of the wine production,including grape skins,seeds,pulp and other ingredients.GP is rich in dietary fiber,unsaturated fatty acids,phenolic compounds and beneficial bacteria,it is feasible to develop and use as a non-grain feed resource.Therefore,in this experiment,12 weaned piglets(28days old)of Songliao black pigs were selected and randomly divided into 2 treatment groups.Each treatment was designed with 3 replicates,and each replicate was 2 pigs.The feed of the experimental group was the normal feed fed by the control group with5% GP supplement.After 4 weeks of feeding,the growth,health status,and intestinal microflora of the piglets were tested.In order to clarify the mechanisms of GP,the phenolic compounds were extracted and analyzed.According to the existing literature,the specific functions of each component were analyzed,and the main effective components were tested in the porcine intestinal epithelial cell line through RNA-seq and cell biology technology.The test results are as follows:(1)Dietary grape pomace can promote the development of jejunum,improve the anti-inflammatory ability of intestinal tissue,and have a positive effect on piglet health.The addition of GP has no adverse effects on the growth and health of weaned piglets.The body weight gain,feed intake,and feed-to-meat ratio are analyzed,and there is no difference between the experimental group and the control group.In the process of analyzing serum biochemical indicators found that GP increased the content of high-density lipoprotein and Ig G,which promoted the health of piglets.After analyzing the intestinal microflora,it was found that GP significantly increased the content of Lactobacillus.delbrueckii,Olsenella.umbonata and Selenomonas.bovis in the intestines.Lactobacillus.delbrueckii can reduce virus replication and regulate inflammation;Selenomonas is a bovine rumen.Olsenella can ferment a variety of carbohydrates,and its increased content helps intestinal metabolism and increases the content of short-chain fatty acids(SCFA).After quantifying the expression of inflammation-related factors and short-chain fatty acid receptor genes in intestinal tissues,it was found that the expression of IL-1β,IL-6,IL-8 and TNF-α was significantly reduced(P <0.05),while the expression of IL-10 and short-chain fatty acid receptors did not change significantly.In addition,through the jejunum tissue section,it was found that the villus length/crypt depth(VCR)of the GP group increased significantly.This increase was due to the significant increase in villus length,and the crypt depth did not change.GP not only has no adverse effects on the growth and health of piglets,but also promotes intestinal development and reduces the expression of intestinal inflammatory factors.In the determination of phenolic compounds contained in GP,a total of 35 phenolic compounds were found,among which maslinic acid(MA)may be an important component in GP.(2)MA has no adverse effects on the IPEC-J2 cell line.Through RNA-seq,it was found that it’s closely related to multiple cell biological processes and pathways.Different concentrations of MA have different effects on the viability of IPEC-J2 cells.Low concentrations can promote cell viability,while high concentrations can inhibit cell viability.MA at a concentration of 0.5 μg/ml can promote IPEC-J2 cell viability significantly.And it has no adverse effects on cell cycle and apoptosis.The results of MA in IPEC-J2 cells measured by RNA-seq found that MA mainly promoted the biological processes of neutrophils,the metabolism of various components,as well as the transmission of some biological signals in the IPEC-J2 cell;and promoted pathways such as body energy metabolism and material synthesis.