Effects Of Dietary Apple Polyphenols Supplementation On Antioxidant Capacity And Intestinal Health In Finishing Pigs

In recent years,plant extracts have been widely used in animal production,in which apple polyphenols(APs)are ideal antioxidants.The intestine is responsible for the digestion and absorption of nutrients and plays an important immune barrier function,which is the most important organ of humans and other animals.There are many studies on apple polyphenols in improving antioxidant capacity and lipid metabolism,but they are mainly based on mouse models or in vitro tests.In addition,there are few studies on the intestinal health of finishing pigs.The purpose of this study was to investigate the effect of dietary apple polyphenols supplementation on the antioxidant capacity and intestinal health of finishing pigs.The experiment adopted a single factor design.36 castrated DLY finishing pigs with initial body weight of 71.25±2.40 kg were selected.They were randomly divided into 3 treatments according to the principle of similar body weight,which include the basal diet group and the basal diet supplemented with 400 mg/kg APs or 800 mg/kg APs treatment groups.There are 6 replicates for each treatment,with 2 pigs per replicate.The test period was 49 days.The results showed that:(1)Compared to the control group,the capacity of total antioxidant in serum was increased in APs groups(P<0.05),and the activity of catalase(CAT)in serum was increased in APs groups(P<0.05).The total antioxidant capacity of the jejunal mucosa was increased in 800 APs group(P<0.05),and the content of malondialdehyde(MDA)in the jejunal mucosa was decreased in APs groups(P<0.05).The activity of CAT in the ileal mucosa was increased in APs groups(P<0.05),and the content of MDA in the ileal mucosa was decreased in APs groups(P<0.05).Compared with the control group,the expression of jejunal SOD1 m RNA was significantly increased in 800mg/kg APs group(P<0.05),the expression of jejunal Keap-1 m RNA was decreased in 800mg/kg APs group(P<0.05),and the expression of jejunal CAT m RNA had a tendency to rise(P=0.05).The expression of ileal CAT and Nrf2 m RNA was increased in APs groups(P<0.05),and the expression of Keap-1 m RNA in the ileum was significantly reduced in APs groups(P<0.05).(2)Compared to the control group,the morphology of intestinal villi was changed in APs groups,the crypt depth of ileum was significantly reduced in APs groups(P<0.05),and the ratio of pile height and crypt depth was remarkably enhanced in APs groups(P<0.05).Dietary apple polyphenols supplementation had no significant effect on the content of DAO,D-LA and I-FABP in the serum(P>0.05).(3)Compared to the control group,the activities of trypsin,maltase and invertase in the jejunal mucosa were significantly increased in 400 mg/kg APs group(P<0.05).The activity of invertase in the ileal mucosa was increased in APs groups(P<0.05).The pH of the ileum was reduced significantly in APs groups(P<0.05).(4)Compared to the control group,the numbers of Lactobacilli and Bifidobacteria in the cecal chyme were increased in 800 mg/kg APs group(P<0.05).The number of Bifidobacteria in colon chyme was increased in 800 mg/kg APs group(P<0.05).The number of Escherichia coli in the colon chyme was reduced in APs groups(P<0.05).(5)Compared to the control group,the content of secretory immunoglobulin A(SIg A)in the ileum was increased in APs groups(P<0.05),and the contents of IL-6 and IL-8 in the jejunum were increased in APs groups(P<0.05).The content of immunoglobulin A(Ig A)in serum was increased in APs groups(P<0.05).In summary,dietary apple polyphenols supplementation can improve the antioxidant capacity of finishing pigs.Apple polyphenols can improve the structure of the intestine villi of finishing pigs and affect the pH and the activity of digestive enzymes to maintain the intestinal morphology and digestion.Apple polyphenols can improve the internal environment of the intestine by increasing beneficial bacteria and reducing pathogenic bacteria.Apple polyphenols can increase the resistance by affecting the immune factors in the serum and intestine of finishing pigs.