Effect of Housing System on Egg Quality During Extended Storage06 June 2014
Current US egg quality standards should effectively define quality for commercially produced conventional cage, enriched colony cage and cage-free aviary eggs, according to a new study led by USDA ARS, which found some differences in eggshell and albumen quality between the eggs from these housing systems over 12 weeks of storage.
Egg producers in the United States are using a variety of commercial egg production systems to provide consumer choice and meet legislative requirements, according to Deana Jones of USDA Agricultural Research Service and co-authors there and at Michigan State University in a paper in Poultry Science. They explain that consumer egg grades in the US were developed for conventional cage production, and it is unclear what effect alternative production systems might have on egg quality during retail and consumer home storage.
Their current study was undertaken to determine what changes in egg quality characteristics occur during extended cold storage for commercially produced conventional cage (battery cage), enriched colony cage, and cage-free aviary eggs.
During 12 weeks of cold storage, egg weight, albumen height, Haugh unit, static compression shell strength, vitelline membrane strength and deformation, yolk index, shell dynamic stiffness, and whole egg total solids were monitored.
Overall, aviary and enriched eggs were significantly (P<0.05) heavier than conventional cage eggs.
Albumen height and Haugh unit (P<0.05) were significantly greater for conventional cage than enriched eggs.
Static compression shell strength was greater (P<0.05) for enriched-cage eggs than those from aviaries.
No overall housing system effects for yolk measurements, shell dynamic stiffness or whole egg total solids were observed.
Albumen height, Haugh unit and yolk quality measurements were all greatest at 0 and lowest at 12 weeks of storage (P<0.05). The rate of quality change among the housing systems for each measured attribute at four, six and 12 weeks was determined. Other than differences in the change of egg weight at four weeks, no significant differences in the rate of quality decline were found among the housing systems.
Jones and co-authors concluded their results indicate that current US egg quality standards should effectively define quality for commercially produced conventional cage, enriched colony cage and cage-free aviary eggs.
Jones D.R., D.M. Karcher and Z. Abdo. 2014. Effect of a commercial housing system on egg quality during extended storage. Poultry Science. 93:1282-1288. doi: 10.3382/ps.2013-03631
You can view the full report (fee payable) by clicking here.