Screening Of Key Proteins Related To Hepatic Metabolism Of Weaned Piglets After Alfalfa Saponins Treatment

The objective of this study was to analyze the effects of alfalfa saponins(AS)on growth performance,immune status,antioxidant capacity,intestinal p H values,intestinal microflora,viscera indices and hepatic proteomics of weaned piglets.Exp.1: A total of 48 piglets(Landrace×Large white)weighing about 8.00 kg weaned at 25 d of age were randomly assigned to 4 treatments(3 replicate pen per treatment with 2 gilts and 2 castrated males per pen)according to variety,birth date,litter,and gender,using complete random single factorial design.Four different levels of AS(0% Control group,0.125% Group I,0.25% Group II and 0.5% Group III)were fed to piglets for 30 d.The results showed that:(1)Diarrhea ratio decreased after AS supplementation;Average daily gain of piglets in Group II were superior;The high addition of AS(0.5%)reduced average daily gain and daily intake,as well as increased f : G.(2)The number of red blood cell,white blood cell and hemoglobin content in AS groups were higher than that of Control group,Moreover,Group II had a higher white blood cell number than the other groups;Thrombocyte of blood in Group II was the lowest,and thrombocyte of blood in Group I and III were higher than that of Control group.(3)The content of TP in Group II,III was very significantly/ significantly higher than that of Group I and Control group;The content of ALB in Group II and III were higher than that of Control group;GLB content had a rising trend with the increasing addition of AS;ALB/GLB in Group II and III were very significantly lower than that of Control group,and Group I was significantly lower than Control group;The contents of ALT and AST in AS groups were lower than Control group;ALP contents in Group I and II were higher than that of Control group;Group II had higher GLU and BUN content than the other groups;The content of Ig G in Group II was the highest;Ig M content was higher in Group III compared with other groups,followed by Group II.(4)AS reduced serum MDA content in weaned piglets.MDA content in Group III,I was very significantly/significantly lower than Control group,;There was no obvious effects on total SOD activity in serum with AS additions;GSH-PX activity in Group II was the highest;AS increased serum T-AOC in piglets,but there was no significant difference among four treatments.Exp.2: At the end of the trial,six piglets(two piglets per pen)from Control group and Group II(0.25% AS)were slaughtered,and the antioxidant capacity of the tissues was detected.The results showed that:(1)AS reduced MDA contents in liver,kidney and spleen,while improved T-AOC;AS significantly increased SOD activity in spleen,but no obvious effects were found in liver and kidney;Group II had a significantly higher GSH-PX activity in kidney compared with Control group;Compared with Control group,CAT activity of Group II was very significantly higher in kidney,and significantly higher in liver.(2)AS improved m RNA expression of CAT in piglet liver,duodenum,jejunum and ileum,moreover,there were very significant differences occured in duodenum and ileum;AS significantly/very significantly enhanced m RNA expression of GSH-PX in piglet liver and jejunum.Exp.3: At the end of the trial,six piglets(two piglets per pen)from Control group and Group II(0.25% AS)were slaughtered,and the digestive physiology of piglets was detected.The results showed that:(1)AS significantly reduced p H values in duodenum and cecum,but no significant effects were found in jejunum and ileum.(2)Dietary AS reduced the numbers of E.coli in jejunum,ileum and cecum,while increased the numbers of Lactobacillus;AS significantly increased the number of Lactobacillus in cecum.(3)The thymus index of Group II was significantly higher than that of Control group;AS had a certain positive role in development of liver,pancreas and kidney.Exp.4: Liver samples from piglets were selected from Control group and Group II(0.25% AS),and three biological replicates were carried out for each group.Then the liver samples were sent to Beijing Proteome Research Center for protein detection.The results showed that:(1)According to our criteria for judging differentially expressed proteins,39 up-regulated proteins and 65 down-regulated proteins were picked out.(2)Via the biological process analysis,the differentially expressed proteins were mainly related to metabolic process,cellular process,biological regulation,multicellular organismal process,immune system process,localization and response to stimulus;Furthermore,they were mainly oxidoreductases,hydrolases,transferases,nucleic acid binding enzymes and ligases,etc.