PSVII-42 Growth performance, gut health, and immune responses of Escherichia coli-challenged weaned pigs fed probiotic-supplemented diets

Abstract

Abstract To evaluate the effects of probiotics on performance and gut health of Escherichia coli-challenged weaned pigs, a total of 28 weaned pigs (initial BW = 8.25 kg) were housed individually in pens and fed 4 experimental diets for 21 d in a completely randomized design. The 4 diets were corn-soybean meal-based basal diet without or with 0.25% antibiotics (neomycin + oxytetracycline), 0.05% Bacillus subtilis DSM 32540, or 0.05% Bacillus pumilus DSM 32539. All pigs were orally challenged with K88 strain of E. coli on d 3. Feed intake and BW data, and blood samples were collected on d 3, 7, 14, and 21. Fecal scores were recorded daily. On d 21, pigs were sacrificed to determine gastrointestinal histomorphology, pH and organ weights. Supplementation of the basal diet with antibiotics or B. pumilus did not affect the overall (d 0 to 21) ADG and G:F. The B. subtilis supplementation did not affect the overall ADG, but tended to increase (P < 0.1) the overall G:F by 15%. Fecal score was unaffected by dietary treatment. Supplementation of the basal diet with either probiotic, but not antibiotics increased (P < 0.05) jejunal villous height and reduced (P < 0.05) cecal digesta pH. Supplementation with B. pumilus tended to increase (P < 0.1) colon weight relative to BW; however, antibiotics or B. subtilis supplementation did not affect colon weight. The addition of B. subtilis to basal diet tended to increase (P < 0.1) serum immunoglobulin A concentration on d 21 of the study; however, such effect was not observed with the addition of antibiotics or B. pumilus. In conclusion, dietary B. subtilis improved G:F and jejunal villous height and reduced cecal digesta pH, indicating that dietary supplementation with B. subtilis at 0.05% could improve growth performance and gut health of weaned pigs.