Effect of a commercial housing system on egg quality during extended storage

Egg producers in the United States are utilizing a variety of commercial egg production systems to provide consumer choice and meet legislative requirements. Consumer egg grades in the United States 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. The current study was undertaken to determine what changes in egg quality characteristics occur during extended cold storage for commercially produced conventional cage, enriched colony cage, and cage-free aviary eggs. During 12 wk 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. Albumen height and Haugh unit (P < 0.05) were significantly greater for conventional cage than enriched eggs. Static compression shell strength was greatest (P < 0.05) for enriched eggs compared with aviary. 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 wk of storage (P < 0.05). The rate of quality change among the housing systems for each measured attribute at 4, 6, and 12 wk was determined. Other than differences in the change of egg weight at 4 wk, no significant differences in the rate of quality decline were found among the housing systems. The results of the current study indicate that current US egg quality standards should effectively define quality for commercially produced conventional cage, enriched colony cage, and cage-free aviary eggs.