PSII-14 Supplementation of Bacillus Amyloquefaciens on Systemic Immunity of Weaned Pigs Experimentally Infected with a Pathogenic E. coli

Abstract

Abstract The objective of this experiment was to investigate the effects of dietary supplementation of Bacillus amyloquefaciens on total and differential blood cell count in weaned pigs experimentally infected with a pathogenic E. coli. A total of 50 weaned pigs (7.41 ± 1.35 kg) were individually housed in disease containment rooms and randomly assigned to one of the 5 treatments: sham control (CON-), sham B. amyloquefaciens (BAM-), challenged control (CON+), challenged B. amyloquefaciens (BAM+) and challenged carbadox (CAR+). The experiment lasted 28 days with 7 days’ adaptation and 21 days after the first E. coli inoculation. The doses of F18 E. coli inoculum were 1010 CFU/3 mL oral dose daily for 3 consecutive days. Whole blood samples were collected from all pigs on d -7, and d 0, 7, 14, and 21 post infection (PI) to measure total and differential blood cell count by complete blood count (CBC) analysis. Supplementation of BAM or CAR increased (P < 0.05) either the percentage or the number of lymphocytes on d 0 before E. coli inoculation. E. coli challenge increased (P < 0.05) white blood cell (WBC) count on d 7 and 21 PI, while supplementation of BAM tended (P < 0.10) to have low WBC on d 7 PI and had lower (P < 0.05) WBC on d 21 PI compared with CON+. Pigs in BAM+ also had lower (P < 0.05) neutrophil count on d 14 PI, pigs fed with CAR had lower (P < 0.05) neutrophil count on d 14 and 21 PI, compared with pigs in CON+. No difference was observed in red blood cell profile among all treatments throughout the experiment. In conclusion, pigs fed with B. amyloquefaciens have similar systemic immune response to pigs in antibiotic group and have relatively lower systemic inflammation caused by E. coli compared with control group.