Skip to main content
ARS Home » Research » Publications at this Location » Publication #250935

Title: Microbiological Difference of Eggs From Traditional Cage and Free Range Production

item Jones, Deana
item ANDERSON, KENNETH - North Carolina State University
item Musgrove, Michael

Submitted to: Poultry Science
Publication Type: Abstract Only
Publication Acceptance Date: 3/4/2010
Publication Date: 7/11/2010
Citation: Jones, D.R., Anderson, K.E., Musgrove, M.T. 2010. Microbiological Difference of Eggs From Traditional Cage and Free Range Production. Poultry Science.

Interpretive Summary:

Technical Abstract: Eggs from alternative production systems are a growing market share in the US. Meeting consumer requests for greater diversity in retail egg options has resulted in some unique challenges such as understanding the food safety implications of eggs from alternative housing practices. A study was conducted to determine what, if any, differences exist between nest run cage and free range produced eggs. A flock of hatch mate brown egg layers were maintained in traditional caged and free range production with egg and environmental sampling every 6 wks from 20-79 wks of age. Aerobic, coliform, and yeast and mold populations were monitored. Traditional caged (TC) egg shells had the highest aerobic levels compared to free range nest box (FRNB) and free range floor eggs (FRF) (3.90, 3.55, and 3.48 log cfu/mL, respectively). FRNB and FRF egg shell coliform levels were greater than TC (1.64, 1.40, and 0.25 log cfu/mL, respectively). FRF egg shell yeast and mold levels were greatest (2.49 log cfu/mL). Range grass (RG) microbial levels were greatest for all populations monitored compared to cage swabs (CS) and nest box swabs (NBS). CS maintained the lowest levels of coliforms and yeast and molds throughout the study but had elevated levels of aerobic bacteria. Seasonal effects were also seen for all monitored populations with summer and fall having the highest levels. Understanding the differences in microbial populations present on traditional cage and free range produced eggs can lead to the development of effective cleaning procedures for free range eggs thus enhancing food safety.