Location: Egg and Poultry Production Safety Research Unit
Title: Frequency and persistence of fecal shedding of Salmonella Enteritidis by experimentally infected laying hens housed in enriched colony cages at different stocking densitiesAuthor
Gast, Richard | |
Guraya, Rupinder - Rupa | |
Jones, Deana | |
ANDERSON, KENNETH - North Carolina State University | |
KARCHER, DARRIN - Purdue University |
Submitted to: International Poultry Scientific Forum
Publication Type: Abstract Only Publication Acceptance Date: 12/2/2016 Publication Date: 1/20/2016 Citation: Gast, R.K., Guraya, R., Jones, D.R., Anderson, K., Karcher, D.M. 2016. Frequency and persistence of fecal shedding of Salmonella Enteritidis by experimentally infected laying hens housed in enriched colony cages at different stocking densities. International Poultry Scientific Forum. Interpretive Summary: Technical Abstract: Human Salmonella Enteritidis infections are often linked with consuming contaminated eggs, so the prevalence of this pathogen in egg-laying poultry is an important risk factor for public health. Salmonella persistence and transmission in commercial egg producing flocks are influenced by the complex environmental influences exerted by management practices and housing facilities. In recent years, alternatives to traditional cage-based housing for laying flocks have been developed in response to the animal welfare implications of poultry housing systems, but the food safety consequences of poultry housing are not completely understood. The present study determined the effects of different bird stocking densities on the frequency and persistence of S. Enteritidis fecal shedding in groups of experimentally infected laying hens housed in colony cages enriched with perching and nesting areas. In replicate trials, groups of laying hens were placed at two stocking densities (648 and 973 sq. cm/bird) in enriched colony cages and (along with a group housed in conventional cages at 648 sq. cm/bird) orally inoculated with doses of 1.0 × 10e8 cfu of S. Enteritidis. At 10 weekly intervals after inoculation of the hens, voided fecal samples were collected from trays beneath each cage and cultured to detect S. Enteritidis. Fecal shedding of S. Enteritidis was detected for up to 10 wk post-inoculation by hens in all three housing treatment groups. The overall frequency of positive fecal culture results was significantly (P < 0.05) higher in conventional cages than in enriched colony cages (at the lower stocking density) for all sampling dates combined (45.0% vs. 33.3%) and also for samples collected at 4-9 wk post-inoculation. Similarly, the frequency of S. Enteritidis detection in feces from conventional cages was significantly greater than from enriched colony cages (at the higher hen stocking density) for all samples combined (45.0% vs. 36.7%) and at 6 wk post-inoculation. Moreover, the frequency of S. Enteritidis fecal recovery from enriched colony cages at the higher hen stocking was significantly greater than from similar cages at the lower stocking density for all 10 sampling dates combined (39.4% vs. 33.3%). These results suggest that stocking density can significantly affect S. Enteritidis intestinal colonization and fecal shedding in laying hens, but some other difference between conventional and enriched colony cage systems appears to exert an additional significant influence. |