日粮添加蛹虫草缓解脂多糖诱导的仔猪肝损伤和骨骼肌蛋白质降解OA北大核心CSTPCD

[Objective]This study aims to explore the effect of cordyceps militaris on the growth and immune performance of early weaned piglets and the mechanism of regulating immune stress.[Method]A total of Duroc × Landrace × large 144 early-weaned piglets of the same age and similar initial weight were randomly divided into 4 groups:NC(basal diet),LPS(LPS+basal diet),LPS+500CM(LPS+basal diet+500 mg·kg-1 CM)and LPS+1000CM(LPS+basal diet+1 000 mg·kg-1 CM).Group NC and group LPS were fed with basal diet,while group LPS+500CM and group LPS+1000CM were fed by fully mixed basal diet with cordyceps militaris(CM)powder according to the proportion.After feeding,6 piglets in each group(half male and half female)were randomly selected and slaughtered.Group LPS,group LPS+500CM and group LPS+1000CM were intraperitoneally injected with LPS according to body weight 4 hoursbefore slaughter,and group NC was injected with the same amount of normal saline.After slaughtering,the longissimus dorsi,heart,liver,spleen,pancreas and kidney were collected for the next detection.[Result]Statistical analysis of body weight and feed intake showed that adding Cordyceps militaris to the diet of piglets had no notable effect on the average daily feed intake of piglets,while the weight of piglets supplemented with 500 mg·kg-1 CM and 1 000 mg·kg-1CM was respectively higher than that of the control group.8.58％(P＜0.05)and 9.08％(P＜0.05).Compared with the NC group,the spleen index of piglets in the LPS group was significantly lower(P＜0.05),while the spleen index of the piglets in the LPS+500CM group and LPS+1000CM group was significantly higher than that in the LPS group(P＜0.05).The detection of liver function biomarkers and total bile acids showed that the liver ALT level of piglets in the LPS group was significantly higher than that of the NC group(P＜0.05),and the levels of AST,LDH,and total bile acids showed an upward trend.The ALT,AST,LDH and total bile acid levels of the LPS+500CM group and LPS+1000CM group with Cordyceps militaris added to the feed were significantly lower than those of the LPS group.The detection of liver antioxidant indicators and inflammatory factor expression showed that the levels of MDA,LPO,T-AOC and the expression of inflammatory factors in the liver of piglets in the LPS group were significantly increased(P＜0.05),while the levels of CAT,GSH-Px and T-SOD were significantly higher.There was a significant decrease(P＜0.01),and feeding piglets with Cordyceps militaris could significantly alleviate the increase or decrease in these indicators.The crude protein and amino acid contents of skeletal muscle in the LPS group were significantly reduced(P＜0.01),and adding Cordyceps militaris to the diet could significantly alleviate the decrease in protein and amino acid contents caused by LPS(P＜0.01).Compared with NC,the expression of inflammatory factors in the LPS group was significantly higher(P＜0.05),while the expression of inflammatory factors after feeding Cordyceps militaris in the diet was significantly lower than that in the LPS group(P＜0.05).The levels of MDA and LPO in the longissimus dorsi muscle of piglets in the LPS group were significantly higher than those in the NC group(P＜0.01),while the levels of T-AOC,CAT,GSH-Px and T-SOD were significantly lower(P＜0.01),adding Cordyceps militaris to the diet can alleviate this abnormal increase or decrease.The phosphorylation levels of Akt,t-mTOR,4EBP1,and FOXO1 were detected and it was found that the LPS group had a decreasing trend compared with the NC group,while the protein expression levels of MAFbx and MuRF1 were significantly increased(P＜0.05).After Cordyceps militaris was added to the diet,the phosphorylation levels of Akt and FOXO1 in the longissimus dorsi muscle of piglets were significantly increased(P＜0.05),while the protein expression levels of MAFbx and MuRF1 were significantly decreased(P＜0.05).[Conclusion]The results show that adding CM to the diet can improve the growth and immune performance of weaned piglets;CM can inhibit the decrease in crude protein and total amino acid content of longissimus dorsi caused by LPS;CM can inhibit liver inflammation and excessive proliferation and apoptosis and hepatocytes and improve liver antioxidant capacity;CM can inhibit longissimus dorsi inflammation,oxidative stress and protein degradation in weaned piglets.Overall,adding CM to the deit can improve the growth and immune performance of weaned piglets,alleviate liver damage and protein degradation cause by LPS,and provide a theoretical basis for screening new feed additives and preventing immune stress in weaned piglets.