Effects of Fruit By-product Extracts on Blood Characteristics, Antioxidant Activity, and Immune Response in Pigs

This experiment was conducted to determine the effects of extracts from fruit by-products on the blood characteristics, antioxidant activities, and immune response to Escherichia coli lipopolysaccharide (LPS) in growing pigs. A total of 96 pigs [(Landrace ${\times}$ Yorkshire) ${\times}$ Duroc] with an initial BW of $27.94{\pm}0.92kg$ were used in a 6-week feeding trial. The pigs were randomly placed into one of four treatment groups with six replications (four pigs per replication) per treatment according to their initial BW. Treatments were: 1) CON (basal diet), 2) PRO (CON + 0.5% procyanidin), 3) HES (CON + 0.5% hesperetin), 4) TAN (CON + 0.5% tannin). At the end of the sixth week, five pigs (total 20 pigs, $BW=27.94{\pm}0.92kg$) were selected from each treatment and injected with LPS ($100{\mu}g/kg$ of BW). Blood samples were collected 3 h after LPS injection to assess anti-oxidative and inflammatory responses. After the LPS challenge, the concentration of serum cholesterol decreased with fruit by-product treatment compared with CON (p<0.05). The administration of TAN increased the concentration of blood total protein compared with the CON group 3 h after LPS challenge (p<0.05). The albumin concentration was also higher with PRO treatment compared to HES treatment (p<0.05). The concentration of IgM was increased by fruit by-product supplementation at 0 and 3 h (p<0.05). In addition, IgG concentration was higher in PRO, HES, and TAN treatments compared to CON treatment at 0 h, and IgG concentrations were also higher in the HES group compared to the CON group at 3 h (p<0.05). The concentration of IgA also increased with fruit by-product treatments at 3 h (p<0.05). In conclusion, dietary supplementation with fruit by-products may moderate the immune response after a LPS challenge in growing pigs.