The influence of genetic strain on production and egg quality amongst four strains of laying hens housed in a cage-free environment.

As the United States egg industry transitions towards cage-free production, genetic strains must be evaluated in their performance in these alternative environments. Transitioning strains that were selected for caged production may elicit challenges in their adaptation to alternative systems, so it cannot be assumed that egg production and quality parameters are comparable in various environments. White strains are historically associated with caged production while brown strains typically occupy cage-free systems. Therefore, the aim of this study was to evaluate the influence of genetic strain on egg production and quality in a cage-free environment. Hy-Line W-36 White, H&N White, Hy-Line Brown, and Bovan Brown laying hen strains were evaluated through numerous egg production and quality parameters throughout the entirety of a lay cycle. H&N White hens in this study were the lowest producing strain demonstrated by producing the least amount of eggs per hen, having the lowest hen-day egg production (p < 0.0001), producing the fewest USDA grade A eggs (p = 0.0023), and the most check eggs (p = 0.0006). However, the Bovan Browns were the least efficient strain as this strain consumed the most feed and had the lowest feed conversion ratio (p < 0.0001). Overall, both white strains demonstrated poorer egg quality compared to brown strains. Hy-Line W-36 White hens had the lowest albumen height, Haugh unit score, yolk color, and yolk weight (p < 0.0001). H&N Whites had the lowest vitelline membrane strength, shell weight, and shell thickness (p < 0.0001). In conclusion, the Hy-Line Brown hens may be better suited for cage-free production based on overall greater egg production and quality metrics compared to the three other strains used in this study. Therefore, this research demonstrates that genetic strain did influence cage-free laying hen performance.