Location: ESQRUTitle: Frequency and duration of fecal shedding of Salmonella serovars Heidelberg and Typhimurium by experimentally infected laying hens housed in enriched colony cages at different stocking densities
|Guraya, Rupinder - Rupa|
|ANDERSON, KENNETH - North Carolina State University|
|KARCHER, DARRIN - Purdue University|
Submitted to: Poultry Science Association Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 5/1/2017
Publication Date: 7/15/2017
Citation: Gast, R.K., Guraya, R., Jones, D.R., Guard, J.Y., Anderson, K., Karcher, D.M. 2017. Frequency and duration of fecal shedding of Salmonella serovars Heidelberg and Typhimurium by experimentally infected laying hens housed in enriched colony cages at different stocking densities. Poultry Science Association Meeting Abstract.
Technical Abstract: Eggs contaminated with Salmonella Enteritidis are leading sources of human salmonellosis, but S. Heidelberg and S. Typhimurium are also egg-associated pathogens. The management practices and housing facilities characterizing different systems for housing commercial egg flocks can influence Salmonella persistence and transmission. Although animal welfare aspects of poultry housing have been widely debated, the food safety ramifications are not thoroughly understood. The present study assessed the effects of 2 different bird stocking densities on the frequency and duration of fecal shedding of strains of S. Heidelberg and S. Typhimurium in groups of experimentally infected laying hens housed in colony cages enriched with perching and nesting areas. In separate trials, groups of laying hens were distributed at two stocking densities (648 and 973 sq. cm/bird) into enriched colony cages and (along with a group housed in conventional cages at 648 sq. cm/bird) orally inoculated with doses of 10e8 cfu of 2-strain cocktails of either S. Heidelberg or S. Typhimurium. At 8 weekly post-inoculation intervals, samples of voided feces were collected from beneath each cage and cultured to detect Salmonella. Fecal shedding of S. Heidelberg continued for 8 wk in all housing groups, but S. Typhimurium shedding ceased after as little as 5 wk (in enriched cages/low stocking density). Following S. Heidelberg infection, the overall frequency of positive fecal cultures for all sampling dates combined was significantly (P < 0.05) greater from either conventional cages (51.0%) or enriched cages/high stocking density (46.5%) than from enriched cages/low stocking density (33.3%). No significant differences in S. Typhimurium fecal isolation were identified between housing groups. The overall frequency of S. Heidelberg fecal recovery was significantly greater than the corresponding frequency of S. Typhimurium recovery from conventional cages (51.0% vs. 29.5%), enriched cages/high stocking density (46.5% vs. 25.3%), and enriched cages/low stocking density (33.0% vs. 22.2%). These results demonstrate that stocking density can affect intestinal colonization and fecal shedding in laying hens for some (but not necessarily all) Salmonella serovars or strains.