Submitted to: Georgia Poultry Conference Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 9/30/2009
Publication Date: 9/30/2009
Citation: Hannah, J.F., Wilson, J.L., Cox Jr, N.A., Richardson, L.J., Cason Jr, J.A., Buhr, R.J. 2009. Potential for horizontal transmission of Salmonella & Campylobacter among caged & cage-free laying hens. Georgia Poultry Conference Proceedings. Interpretive Summary:
Technical Abstract: With an increasing number of table egg producers transitioning to cage-free housing systems, it is important to determine what effects housing systems may have on the spread of Salmonella and Campylobacter among hens. In each of five sequential trials, hens were inoculated with marker strains of Salmonella (S. Typhimurium or S. Enteritidis) and either a marker Campylobacter strain (C. coli) or field strain (C. jejuni) at 56-72 wk-of-age. Challenged hens were then comingled with non-challenged hens for two weeks post-inoculation, in either conventional colony cages, on all wire slats, or on all litter flooring systems all within the same room. In summary, the potential for horizontal transmission of Salmonella was not significantly influenced by housing system, but the potential for horizontal transmission of Campylobacter was significantly greater on the litter floors than in the cages, with the potential for horizontal transmission on slats being similar to that of both litter and cages. Residual S. Typhimurium was detected in the ceca of non-challenged hens from each housing system and when this data was included, the potential for horizontal transmission of Salmonella was significantly greater on the litter floors than in the caged and slat housing systems. This is most likely due to the fact that hens are separated from their fecal droppings in these two housing systems. S. Typhimurium and C. jejuni colonized within the intestinal tracts and translocated to other internal organs of challenged hens at a higher rate than S. Enteritidis and C. coli. From all of the organs sampled, S. Enteritidis was detected in only one LRT sample. The poorer colonization of S. Enteritidis in this experiment may be misleading as field strain may have higher colonization and therefore greater potential for horizontal transmission. As more table egg producers move to cage-free systems, it is essential to determine what effect the housing systems will have on the potential for horizontal transmission of Salmonella and Campylobacter among laying hens.