Submitted to: BARC Poster Day
Publication Type: Abstract only
Publication Acceptance Date: 4/7/2011
Publication Date: 4/18/2011
Citation: Lee, K., Lillehoj, H.S., Lee, S.H., Jang, S.I., Babu, U.S., Park, M., Kim, D., Chun, J., Song, W., Neumann, A.P., Siragusa, G.R. 2011. Effects of Bacillus subtilis-based direct-fed microbials on growth performance, immune characteristics and resistance against experimental coccidiosis in broiler chickens. BARC Poster Day. p.26. Interpretive Summary:
Technical Abstract: The present experiment was conducted to study the effects of dietary Bacillus-based direct-fed microbials (DFMs) on cytokine expression patterns, intestinal intraepithelial lymphocyte (IEL) subpopulation, splenocyte proliferation, macrophage functions and resistance against experimental coccidiosis in broiler chickens. Birds were fed diets containing one of eight Bacillus subtilis strains (designated Bs2084, LSSAO1, 3AP4, Bs18, 15AP4, 22CP1, Bs27, and Bs278) or one multiple-strain DFM product (AVICORRTM) for 21 days, and then the chickens were uninfected or orally infected with 5000 Eimeria maxima (EM) oocysts. DFMs did not significantly modify body weight gain, but altered intestinal morphometric measurements. At day 21 (before EM challenge), strong phagocytosis ability using BSA-coated fluorescent latex beads and GFP-labeled salmonella was seen in birds given Bs18, 15AP4, Bs27, or Bs278 compared with the no DFM control group. In addition, splenic lymphocyte proliferation, intestine IEL subpopulations, and cytokine mRNA levels in IELs were increased, decreased, or unchanged compared with controls depending on the DFM used. At day 27 (6 days post infection), EM-induced reduction of body weight gain and intestinal lesions were significantly decreased by adding 15AP4 or Bs27 into broiler diets compared with no DFM/EM inoculated control. All experimental diets increased concanavalin A-induced splenocyte mitogenesis in infected broilers compared with the no DFM/EM inoculated control. The present study provides the scientific evidence that Bacillus-based DFMs can modulate the host immunity and thus provide the protective immunity against enteric pathogens in broiler chickens.