Are the males to blame? A pilot study investigating the association between rooster presence and traumatic skin lesions in broiler breeder hens

This pilot study investigated the effects of rooster on skin lesion prevalence in broiler breeder hens and explored the association between lesions and ovarian activity assessed by portable ultrasound. In two Ross 308 breeder flocks, 500 hens were housed without roosters (NO-RO), while the remaining birds were managed conventionally (NORM). Skin lesions were assessed every 14 days using transect walks. Lesions on the back, thighs and under the wings, in addition to the size of the lesion (±5 cm) were recorded. Lesion prevalence increased with age, with most injuries located under the wings. In flock 1, lesion prevalence and size were equal between NO-RO (14 hens, 2.8%) and NORM (185 hens, 2.64%) at 31 weeks of age. In flock 2, only one lesion was observed in NO-RO birds, while the prevalence in NORM was numerically lower than that in flock 1 (46 hens, 0.65%) at 32 weeks of age. Ultrasound examination showed that 57% of the injured hens had no mature ovarian follicles. The occurrence of lesions in hens housed without roosters suggests that factors other than males may contribute to injuries. These findings highlight the potential welfare and economic implications of injuries. Owing to the nature of this study, the results are hypothesis-generating.