This study evaluates the effect of housing environment on the egg quality characteristics of brown egg layers as many different environments are currently used in the industry. Battery cages, barren colony cages, enriched colony cages, cage-free, and free-range environments were evaluated. Overall, all egg quality measurements were affected by housing environment (p < 0.01) except for vitelline membrane strength, elasticity, and egg solids. Eggshells and yolks were lightest in barren colony cages and darkest from free-range hens (p < 0.0001). Free-range eggs were heavier than eggs from all other environments (p < 0.0001). Cage-free eggs had lower albumen height and Haugh units than other environments (p < 0.0001). Lastly, cage-free and free-range eggs had stronger eggshells than the other environments (p < 0.0001), and free-range eggs had more elastic eggshells than eggs from conventional battery cages and barren colony cages (p < 0.01). Access to the range seemed to give free-range hens different nutritional advantages, which allowed for the darker yolks and shells. Furthermore, eggs from barren colony cages seemed to exhibit more negative characteristics. Simply adding enrichments to colony cages did not improve or detract from egg quality. From this research, it appears that, as the industry moves toward extensive environments, the egg quality of brown egg layers will improve.

Currently, the egg industry is experiencing a shift in demand for eggs from cage-free environments. This study aims to evaluate the egg quality parameters of white eggs laid in several different housing environments utilized in the industry. Egg quality parameters from battery cages, barren colony cages, enriched colony cages and cage-free pens were compared. Overall, most egg quality parameters were found to be different across housing environments. Battery cages produced the heaviest eggs and eggs with the highest Haugh unit (p < 0.05). Cage-free hens produced eggs with the darkest yolks, lowest Haugh units, strongest shells and highest solids percentage compared to other environments (p < 0.05). This study did not detect differences between any housing environment in shell color, shell elasticity, vitelline membrane strength or vitelline membrane elasticity (p > 0.05). Moreover, this study did not detect any differences in egg quality parameters between enriched and barren colony cages (p > 0.05). It appears that white egg-laying hens had superior egg quality performance in caged environments and that cage-free pens only improved yolk color. Furthermore, it appears that simply adding enrichments to cages does not affect any egg quality parameters. From the results of our study, we believe that current intensive environments, such as cages, are the most beneficial for white egg layer egg quality and that as the industry moves toward cage-free, new strategies will need to be developed to preserve egg quality. More research is needed, particularly evaluating free-range environments.

Consumer demand for retail cage-free eggs is driving the layer industry towards greater use of extensive housing environments. However, there is limited research on how these environments affect egg production characteristics of brown egg layers, as was the focus of this study. Five housing environments were evaluated under typical industry conditions, including conventional cages, enrichable colony cages, enriched colony cages, cage-free and free-range. Three different brown egg laying strains were housed in the different housing environments and managed according to standard husbandry practices and stocking densities. Data collection for the strains began at 17 weeks of age, with a base period of 28 days for feed weigh backs and egg quality assessments. Housing environment had a highly significant (p < 0.0001) effect on all egg production characteristics measured, including egg production rates (% hen-day and % hen-housed), feed consumption (g/bird/day), feed conversion (egg g/feed g), and mortality rate (%) as well as percent grade A, B, and loss. Previous research revealed better egg production metrics for white egg layers in caged environments than extensive environments. In contrast, we observed brown egg layers had optimum production results for the free-range housing environments, and the poorest performance in enrichable colony cages.

Stocking density is one of the major concerns in all production systems, which is why lawmakers, retailers, and consumers are increasingly concerned about this issue and its relation to animal welfare. The aim of this study was to identify if stocking density had an effect on white egg layer production, egg quality, bird health, and welfare parameters. For this study, five stocking densities were evaluated in colony cages: 1342 cm²/hen, 897 cm²/hen, 671 cm²/hen, 535 cm²/hen, and 445 cm²/hen. Egg production and physical egg quality were measured. Hen health and welfare parameters including corticosterone levels, H/L, oxidative stress pathways, jejunum tight junction protein expression, bone health, gut histology, body condition, and cytokine expression were evaluated. The results from this indicated that higher stocking densities resulted in lower production but larger eggs, while feed efficiency remained unaffected. Furthermore, physical egg quality parameters also remained unaffected. When stress and welfare parameters were analyzed, this research identified that decreasing stocking density did not affect jejunum oxidative stress pathways, pro-inflammatory cytokine expression, bone health, or intestinal health. At the final sampling period (69 weeks), the highest stocking density demonstrated higher corticosterone concentrations and IL-10 expression compared to the lowest stocking density. Furthermore, feather scores were found to be poorer as density increased. Finally, the highest density had higher Hansen’s test scores compared to other densities, which indicates a greater fear response. In conclusion, it appears that decreasing stocking density may provide some benefits in production and welfare to commercial egg layers, particularly at the end of the laying cycle.

The housing environment has become a critical issue for consumers of eggs and egg products. Therefore, it is imperative to understand how various housing environments can affect the modern laying hen. In this study, alongside the 40th NC layer performance test, four different housing environments were chosen based on industry prevalence, which include conventional cages, barren, enrichable colony cages, enriched colony cages, and cage-free environments. Hens in these environments were raised following standard feeding and lighting practices. This study found that conventional cage and enriched colony cage hens had the highest egg production level, while hens from the barren colony cages had the lowest production level. Feed efficiency followed a similar trend, where conventional cage and cage-free hens had the best feed efficiency, followed by enriched colony cage and barren colony cage hens. This study also found that conventional cage hens had the largest eggs, while cage-free hens had the smallest eggs. Cage-free and conventional cage hens had the lowest mortality rate, while hens in the barren colony cage had the highest mortality rate. From the data shown, it appears that standard, conventional cages provide white egg layers with the most optimal environment for production performance. However, a further evaluation of health and stress is needed to determine which environment provides the hen with optimal welfare.

Food safety is a major concern for commercial poultry producers and consumers. Currently, there is also pressure from retailers and legislators to increase the space per hen in cages. Five different density treatments consisting of six (208 in²/bird), nine (139 in²/bird), twelve (104 in²/bird), fifteen (83 in²/bird), and eighteen birds (69 in²/bird) per cage were examined in colony cage environments. Microbiological tests were performed at 39, 55, and 68 weeks of age. The populations of total aerobic bacteria; E. coli/coliform; Enterobacteriaceae; and yeasts and molds from an eggshell rinse, egg content, and cloacal swabs were enumerated. The prevalence of Salmonella spp. in these samples was also monitored. Overall, no bacteria were detected in any of the egg content, and there were no differences (p > 0.05) between treatments for the shell rinse. Stocking density did not influence the eggshell microbiota of the hens. Hens housed at 104 in² per hen showed higher levels of total aerobic bacterial counts from the cloaca compared to hens at 208 in² and 69 in² per hen. Hens housed at 139 in² per hen had the highest level of cloacal molds. This research demonstrates that stocking density does not influence eggshell microbiota or Salmonella contamination of the eggshell or cloaca, thereby indicating that allowing more space per hen will not positively or negatively affect the prevalence or concentration of foodborne pathogen-associated bacteria in or on the eggs.