|Lee, Kyung Woo|
Submitted to: Avian Diseases
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/29/2012
Publication Date: 5/20/2012
Citation: Lee, K., Lillehoj, H.S., Lee, S.H., Jang, S.I., Ritter, D.G., Bautista, D.A., Lillehoj, E. 2012. Impact of fresh or used litter on the post-hatch immune system of commercial broilers. Avian Diseases. 55:539-544. Interpretive Summary: Lack of information on how different types of litters used in poultry production affect developing immune system of young broiler chickens hinders the development of effective litter control strategy for poultry industry. In this report, ARS scientists collaborated with field veterinary scientists to investigate the effect of different types of litters on host innate immune system. For this purpose, fresh wood shavings or used litter obtained from commercial poultry farms were used and various immune parameters were assessed for innate immunity status. At 43 days post-hatch, chickens raised on used litter showed more active immune system compared to those grown on fresh litter. These results provide evidence that the exposure of growing chickens to used poultry litter stimulates antibody and cell-mediated immune responses. This new information will help industry scientists to design a more effective strategy to manage poultry litter.
Technical Abstract: This study was carried out to investigate the effects of exposure of growing broiler chickens of commercial origin to used poultry litter on intestinal and systemic immune responses. The litter types evaluated were fresh wood shavings or used litter obtained from commercial poultry farms with or without a history of gangrenous dermatitis (GD). Immune parameters measured were serum nitric oxide (NO) levels, serum antibody titers against Eimeria or Clostridium perfringens, mitogen-induced spleen cell proliferation, and intestinal intraepithelial lymphocyte or splenic lymphocyte subpopulations. At 43 days post-hatch, birds raised on used litter from a GD farm had higher serum NO levels and greater Eimeria or C. perfringens antibody levels compared with chickens raised on fresh litter or used, non-GD litter. Birds raised on non-GD and GD used litter had greater spleen cell mitogenic responses compared with chickens raised on fresh litter. Finally, spleen and intestinal lymphocyte subpopulations were increased or decreased depending on the litter type and the surface marker analyzed. While it is likely that the presence of Eimeria oocysts and endemic viruses varies qualitatively and quantitatively between flocks and, by extension, also varies between different used litter types, we believe that these data provide evidence that exposure of growing chicks to used poultry litter stimulates humoral and cell-mediated immune responses, presumably due to contact with contaminating enteric pathogens.