The impact of strain and cage type on the welfare of laying hens in different seasons

Abstract

The aim of this study was to determine the effects of strain and cage type on the welfare of laying hens in commercial flocks over different seasons. A 2 x 2 x 3 factorial design was used to evaluate the effects of strain (white and brown layers) and cage type (conventional and enrichable battery cages) on the welfare of laying hens over three seasons (winter, spring and summer). The Welfare Quality® Assessment Protocol for Poultry was used to assess the welfare of laying hens. The strain and cage type significantly affected the welfare of the laying hens, which varied according to the season. Hens from the brown strain exhibited higher occurrences of FPD, keel bone abnormalities, and feather loss on the head and neck. White strains displayed a greater percentage of hens with abnormalities in the toe, comb, and beak, along with pecking wounds on the comb and extensive feather loss on the back, rump, and belly. A higher prevalence of comb abnormalities was observed in conventional cages. Hens in enrichable cages had higher rates of FPD, toe, comb and beak abnormalities, as well as pecking wounds on the comb and extensive feather loss. As a result, it was concluded that enrichable cages have a more adverse impact on the welfare of laying hens, with welfare losses in enrichable cages being more pronounced in brown hens compared to white hens and with interactions between strain and cage type varying seasonally.