136 Awardee Talk: Effects of Monoglycerides on Intestinal Morphology and Immune Responses of Weanling Pigs Experimentally Infected with a Pathogenic Escherichia Coli

Abstract

Abstract This study aimed to investigate the effects of monoglycerides on intestinal morphology and immune responses of weanling pigs experimentally infected with Escherichia coli (E. coli) F18. Weaned pigs [n = 60; body weight (BW) = 6.49 ± 0.74 kg; around 21 d old] were individually housed and fed with one of four diets (15 replicates/diet): 1) control diet (CON); 2) CON+0.3% monoglycerides; 3) CON+3000 mg/kg ZnO; and 4) CON+50 mg/kg antibiotics (carbadox). The experiment lasted 28 days with 7 days before and 21 days after first inoculation (d 0). All piglets were orally challenged with E. coli F18 (1010 CFU/3 mL) for 3 consecutive days. Serum samples were collected on d 2, 5, and 21 post-inoculation (PI) to measure the concentration of tumor necrosis factor (TNF) -α, C-reactive protein, and haptoglobin. Duodenum, jejunum, and ileum segments were collected on d 5 PI (6 pigs/treatment) and on 21 PI (9 pigs/treatment) to measure intestinal morphology. Jejunal and ileal mucosa were also collected to measure the mRNA expression of immune responses related genes. Data were analyzed by ANOVA using PROC MIXED of SAS with randomized complete block design. Supplementation of high dose ZnO tended (P = 0.056) to reduce serum haptoglobin on d 0, reduced (P < 0.05) serum haptoglobin on d 2 and 5 PI, and reduced (P < 0.05) serum C-reactive protein on d 21 PI. Pigs fed with monoglycerides had less (P < 0.05) serum haptoglobin on d 5 PI, compared with CON. Pigs supplemented with high dose ZnO had more (P < 0.05) goblet cell numbers per villus, greater (P < 0.05) villi area and villi height, and greater (P < 0.05) villi height:crypt depth ratio in duodenum than pigs in other treatments on d 5 PI. Supplementation of monoglycerides, high dose of ZnO, or antibiotics reduced (P < 0.05) ileal crypt depth compared with CON on d 5 PI. Pigs in high dose ZnO group tended (P = 0.064) to have the largest villi height:crypth depth ratio in the ileum, followed by pigs in monoglycerides and antibiotics groups on 5 PI. Consistently, pigs fed with high dose ZnO expressed less (P < 0.05) TNF α, IL6, IL10, IL12, IL1A, IL1B, and PTGS2 in ileal mucosa, compared with other treatments on d 5 PI. However, no difference in the expression of listed genes was observed between pigs fed with monoglycerides vs. high dose of ZnO. Pigs supplemented with monoglycerides expressed least (P < 0.05) PTGS2 in ileal mucosa compared with other treatments on d 21 PI. In conclusion, dietary supplementation of 0.3% monoglycerides reduced intestinal and systemic inflammation of weaned pigs infected with E. coli F18, although the efficacy was not comparable to high dose ZnO.