Effects Of Fermented Cotton Meal Rich In Cottonseed Peptide On Growth Performance,immune Function And Protein Metabolism Of Broilers

Objective:The purpose of this experiment was to research the effects of cottonseed peptide-rich fermented cotton meal on the growth performance,immune function and protein metabolism of AA broilers by the fermentation of Bacillus subtilis-1,Saccharomycopsis fibuligera Su 2019 and combined.Method:(1)By using laboratory-screened solid-state fermented cotton meal of Bacillus subtilis-1,Saccharomycopsis fibuligera Su 2019 and composite bacteria,the conventional nutrient components,cottonseed peptide content and molecular weight distribution of cottonseed peptide were measured before and after fermentation,respectively.(2)240 1-day-old healthy AA broiler hens and were randomly divided into 4 groups,with 4 replicates in each group and 15 birds per replicatein.6% unfermented cottonseed meal(cottonseed peptide content 1.926g/kg)was added to the diet of the control group,and 4%,6%,and8% of cottonseed peptide-rich fermented cottonseed meal(cottonseed peptide content 8.136g/kg,12.204g/kg,16.272g/kg,respectively)was added to the diet of the test group,determination of growth performance and immune function related indicators of broilers.(3)To determine the protein deposition,apparent digestibility of nutrients,hormone content in serum,intestinal enzyme activity and small intestinal peptide transport vector Pep T1,the expression of upstream and downstream effector factors of protein metabolism m TOR signaling pathway,and to study the effect and mechanism of fermented cottonseed meal rich in cottonseed peptide on protein metabolism in AA broilers.Results:Experiment1:After Bacillus subtilis-1,Saccharomyces fibuligera Su2019 and compound fermentation can reduce the content of ADF,NDF,EE in cotton meal,increase the content of DM,CP,Ash,Ca and P,total free Amino acid and cottonseed peptide,effectively degrade large protein into small molecule peptide and free amino acid in cotton meal.Experiment 2: Adding 6% and 8%(cottonseed peptide content of 12.204 g/kg and 16.272g/kg)to the AA broiler diet can increase the ADG and ADFI of broilers,and the 6% group were reduced F/G.1 to 21 days,adding 6% and 8% of cottonseed peptide-rich fermented cotton meal to the diet,was extremely significantly increased the content of Ig M in serum(P<0.01),adding 8% fermented cottonseed meal rich in cottonseed peptide was extremely significantly rised the content of IL-6 and Ig A in serum(P < 0.01),and were increased the thymus index,macrophage phagocytosis index,content of IL-2,IL-1β(P<0.05).22 to 42 days,adding 6% fermented cottonseed meal rich in cottonseed peptide to the diet,was extremely significantly improved of broiler bursal index,Ig M and Ig A levels in serum(P< 0.01),and were increased macrophage phagocytosis index and content of TNF-α in serum(P < 0.05).Experiment 3:(1)Adding 6% and 8% of cottonseed peptide-rich fermented cottonseed to AA broiler diets for 1 to 21 days,was extremely significantly improved the enzyme activity of trypsin and chymotrypsin in duodenum,jejunum,and ileum(P<0.01),were increased the expression of Pep T1 in duodenum(P < 0.05).Adding 6% fermented cottonseed meal rich in cottonseed peptide was extremely significantly rised feather and carcass protein deposition,apparent digestibility of EE and metabolic energy,and the expression of Pep T1 in the jejunum and ileum,the expression of PI3 K in pectoral muscles(P < 0.01).Adding 8% fermented cottonseed meal rich in cottonseed peptide was extremely significantly improved the content of T4 in serum,the expression of Pep T1 in the ileum and PI3 K in the pectoral muscle(P<0.01),were improved the apparent digestibility of metabolic energy and the content of GH,INS in serum(P<0.05).(2)Adding 6% and 8% of cottonseed peptide-rich fermented cottonseed to AA broiler diets for 22 to 42 days,was extremely significantly increased the enzyme activity of duodenum,jejunum,and ileal trypsin,feather deposition and content of GH,INS.Adding 6% fermented cottonseed meal rich in cottonseed peptide was extremely significantly improved the enzyme activity of chymotrypsin in duodenum,jejunum,and ileum,were increased the expression of Pep T1 in duodenum,jejunum,and ileum and m TOR in pectoralis and AKT in leg muscles(P<0.01).Significantly increased the apparent digestibility of EE,the expression of AKT in pectoral muscles,and PI3 K in liver and leg muscles(P<0.05).Adding 8% cottonseed peptide-rich fermented cotton meal was extremely significantly rised the expression of AKT in pectoral muscle and S6K1 in leg muscle(P<0.01),and significantly increased the expression of S6K1 in the liver(P<0.05).Conclusion:By solid state fermentation Bacillus subtilis-1 and Saccharomycopsis fibuligera Su 2019,which can improve the nutritional value of cotton meal and increase the content of free amino acids,and produce 21.44% cottonseed peptid,and effectively degrade macromolecular protein into free amino acid and cottonseed peptide.The growth performance and immune function of AA broilers were improved by adding cottonseed peptide-rich fermented cotton meal to the diet,and increase the broiler protein metabolism related indicators and the expression of small intestine small peptide transport vector Pep T1,upregulate the expression of genes related to protein metabolism in the m TOR pathway.