PS10-17. Effects of Fermented Pomegranate Pomace with Clostridium Butyricum on the Systemic Immunity of Weaned Piglets Challenged with F18 Enterotoxigenic Escherichia coli.

Abstract This study aimed to investigate the effects of fermented pomegranate pomace (FPP) with Clostridium butyricum on the systemic immunity in weaned piglets experimentally infected with F18 enterotoxigenic Escherichia coli (ETEC). A total of 50 piglets (6.66 ± 1.01 kg; 21 to 24 days of age) were individually housed and randomly assigned to five dietary treatments (10 replicates/treatment) in a randomized complete block design, with initial body weight and sex as random factors. The dietary treatments include: control, supplemented with 1% pomegranate pomace (PP), 2 × 109Clostridium butyricum (CB), a combination of 1% PP and 2 × 109 CFU/kg CB (PPCB), and 1% FPP. The FPP was prepared by fermenting pomegranate pomace with Clostridium butyricum, containing approximately 5.7 ×1010 CFU/kg and a final pH 5.7 to 6.0. The experiment lasted 28 days, including 7 days of adaptation and followed by 21 days post inoculation (PI). All pigs were orally inoculated with F18 ETEC (1010 CFU/3 mL) for three consecutive days from day 0 PI. Blood samples were collected on day 0 before ETEC inoculation, and on days 2, 7, 14, and 21 PI to analyze complete blood cells (CBC) count. Data were analyzed by AVOVA using PROC MIXED of SAS, with individual pig as the experimental unit. The counts of white blood cell, neutrophil, lymphocytes, and monocytes increased (P < 0.05) on days 2 and 7 PI, but decreased (P < 0.05) on day 21, suggesting ETEC infection induced systemic inflammation in pigs. ETEC infection also reduced (P < 0.05) red blood cell counts and hemoglobin levels. Throughout the experimental period, pigs supplemented with PPCB and FPP had the lowest (P < 0.05) neutrophil percentage among all treatments. Pigs supplemented with PPCB or FPP had a lower neutrophil percentage (P < 0.05) and neutrophil:lymphocytes (P = 0.08) compared with pigs in the control or CB on day 0 before inoculation. Pig supplemented with FPP had the lowest (P < 0.05) lymphocyte count and the highest (P < 0.05) platelet count on day 2 PI and the lowest (P < 0.05) mean platelet volume on day 7 PI among all treatments. On day 21 PI, pigs in the PP group had the lowest (P < 0.05) hemoglobin concentration and mean corpuscular volume among all treatments. In conclusion, F18 ETEC infection induced acute systemic inflammation. Dietary supplementation with PPCB or FPP may modulate systemic immune responses in weaned pigs before and after F18 ETEC inoculation. Serum inflammatory biomarkers will be further analyzed to better characterize the systemic immune responses of newly weaned pigs.