Submitted to: International Poultry Scientific Forum
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/28/2010
Publication Date: 3/1/2010
Citation: Lillehoj, H.S., Lee, S.H., Siragusa, G.R., Neumann, M.A., Rehberger, T.G., Lee, K.W., Li, G.X., Jang, S.I., Park, S., Kim, D.K., Babu, U.S. 2010. Effects of direct-fed microbials on growth performance, gut morphometry, and immune characteristics in broiler chickens. International Poultry Scientific Forum, Atlanta, GA, January 25-26, 2010. P. 19. Interpretive Summary: Development of safe and effective alternative methods is becoming a priority for poultry industry due to increasing concerns about increasing drug-resistance of poultry pathogens. Although drugs have been traditionally used to control many diseases of poultry, the results of recent ARS study indicate a potential non-drug application of dietary strategy to control mucosal pathogens of poultry. In this report, ARS scientists in collaboration with scientists at Danisco, University of Maryland and U.S.FDA investigated immunostimulating effects of direct-fed microbial (DFM) food supplements. Feeding broiler chickens with DFM-supplemented diets altered intestinal morphometric measurements with increased villus height and crypt depth compared with non-DFM fed controls. Certain DFM supplementation enhanced innate immunity and improved various aspects of host intestinal immune response. These results provide a rational scientific basis to utilize DFMs as immunomodulating agents in poultry production to reduce the use of antibiotics.
Technical Abstract: This study was conducted to compare growth performance, gut morphometry, and parameters of local and systemic immunity in broiler chickens fed for 22 consecutive days with a diet supplemented with one of eight Bacillus spp. as a direct-fed microbial (DFM), a commercial product incorporating three DFMs , or a non-supplemented diet. DFM-fed birds showed altered intestinal morphometric measurements as revealed by increased villus height and crypt depth compared to non-DFM fed controls. In addition, serum levels of a-1-acid glycoprotein as an inflammatory marker were reduced in DFM-fed birds, while splenic lymphocyte proliferation, intestine intraepithelial lymphocyte (IEL) subpopulations, and cytokine mRNA levels in IELs were changes (increased, decreased, or unchanged) compared with controls depending on the DFM used. These results provide a rational scientific basis for future studies to investigate DFMs as immunopotentiating agents to enhance host protective immunity against enteric pathogens in broilers chickens.