STRESS EFFECTS ON IMMUNITY AND PHYSIOLOGY OF POULTRY
Location: Egg Safety and Quality
Title: The Impact of Different Housing Systems on Egg Safety and Quality
Submitted to: Poultry Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: March 26, 2010
Publication Date: May 14, 2010
Citation: Holt, P.S., Davies, R.H., Dewulf, J., Gast, R.K., Huwe, J.K., Jones, D.R., Waltman, D., Willian, K.R. 2010. The Impact of Different Housing Systems on Egg Safety and Quality. Poultry Science. 90:251-262.
Interpretive Summary: There is a movement in the U.S. to change laying hen housing from the standard battery cage to either enriched cages or noncage systems. Before such a change is undertaken, it is important understand how these changes will affect the safety and quality of the eggs coming from the facilities. Safety can be microbiological, affecting hen infection and subsequent egg contamination with Salmonella enterica serovar Enteritidis (S. enteritidis), or chemical where contact with the ground can result in exposure to and consumption of agents such as dioxins, heavy metals, or pesticides which ultimately end up in the eggs. Quality effects include the shell, yolk, or albumen as well as functional, composition, and nutritional egg characteristics. External influences such as hen breed, season, and disease/vaccination status affect egg safety and quality and must be included as part of the over-all evaluation.
A move from conventional cages to either an enriched cage or a noncage system may affect the safety and/or quality of the eggs laid by hens raised in this new environment. The safety of the eggs may be altered either microbiologically through contamination of internal contents with Salmonella enterica serovar Enteritidis (S. enteritidis) and/or other pathogens, or chemically due to contamination of internal contents with dioxins, pesticides, or heavy metals. Quality may be affected through changes in the integrity of the shell, yolk, or albumen along with changes in function, composition or nutrition. Season, hen breed, flock age, and flock disease/vaccination status also interact to affect egg safety and quality and must be taken into account. An understanding of these different effects is prudent before any large scale move to an alternative housing system is undertaken.