Evaluation Of Protein Feed Quality From Different Sources And Its Effects On Intestinal Microflora Structure Of Weaned Piglets

The amount and quality of dietary protein can decide the quantity of protein which enter into the hindgut of piglets for fermentation,and then affect the growth and intestinal health of piglets.Effects of protein level on the growth and gut microbes of piglets have been demonstrated by other people,however,only several studies about the sources of protein were reported.In view of the unclear effects of different sources of dietary protein on serum immunity and gut microbes in weaned piglets,these following two experiments were conducted.Experiment 1: Comparative analysis of nutritional components,anti-nutritional factors and in vitro digestibility of soybean meal and fermented soybean meal.In total,10 representative samples of soybean meal and fermented soybean meal from different sources were collected.Then contents of main nutrients such as crude protein,amino acid,acid soluble protein,and anti-nutrients factors such as glycinin,β-conglycinin,trypsin inhibitor,oligosaccharide were determined.Four kinds of fermented soybean meal were selected by cluster analysis and the in vitro digestibility of dry matter,energy,crude protein,amino acid were measured.Compared with soybean meal samples,the average contents of crude protein and acid soluble protein in fermented soybean meal increased by 7% and 2.69%,and the average content of glycinin and β-conglycinin decreased by 67% and 62%,respectively.It indicated that the nutritional value of fermented soybean meal and soybean meal from different sources were different and the quality of fermented soybean meal was better than soybean meal.Experiment 2: Effects on different sources of dietary protein feed for serum immunity and intestinal microflora in weaned pigletsA total of 24 weaned piglets with a body weight of 8.58 ± 0.44 kg were used in the experi ment.Piglets were randomly divided into three dietary treatments with eight replicates of one per cage.The level of dietary protein was 16% and fermented soybean meal(FSBM)which were obta ined by comparative analysis in the previous chapter,fish meal(FM)or fermented soybean meal + fish meal(FSBM + FM)were applied as protein sources.On day 28,compared with the FSBM and FM groups,the FSBM + FM group significantly increased average daily gain,immunoglobuli n A(IgA),IgG,IgM(P < 0.05),and significantly reduced the content of Interleukin-1β(IL-1β),I L-6,tumor necrosis factor-α(P < 0.05).In colonic digesta,relative abundance of unidentified_Clos tridiales and Terrisporobacter in the FSBM + FM and FSBM groups increased significantly(P < 0.05),relative abundance of unidentified_Enterobacteriaceae in the FM group was higher than in t he FSBM and FSBM + FM groups(P > 0.05).Furthermore,the microbial abundance has a certai n correlation with immune indicators.In addition,the contents of acetic acid and butyric acid in t he FSBM + FM group were significantly higher than those in the FSBM and FM groups(P < 0.05).In summary,compared with the single dietary protein source,the combination of fermented soybean meal and fish meal as dietary protein sources can improve the serum immunity and regulate the intestinal microbiota of weaned piglets.In addition,the research results can provide theoretical basis for the rational use of different protein resources in livestock production,and can also provide technical support for improving the utilization efficiency of existing protein resources in China.