Nociceptive thresholds in broiler chickens are modulated by lameness of their progenitors and sex category

There are increasing concerns about fast-growing broiler’s welfare. The impact of lameness issues of parental hens and cockerels to their immediate broiler’s offspring remains underexplored and was an objective of this study. Additionally, it was added the novelty to investigate nociceptive responses of these broilers in the field. The study was conducted in commercial settings in Brazil including a reproduction farm, an industrial-scale hatchery, and a rearing farm. Parental-birds were gait scored as lame(C) and non-lame(S) and combined into four mating groups: SS, SC, CS, and CC. 371 adult broilers, immediate progeny of these parents, evaluated for lameness and nociceptive thresholds. Although no treatment effects were observed, when comparing sexes, regardless parental conditions, male broilers exhibited higher 0–5 gait scores than females (males 1.74, females 1.20). Males had also higher nociceptive thresholds and this reduced sensitivity was more pronounced in their left legs. The sex-based analysis indicated that male broilers descended from lame females mated with non-lame males, presented higher nociceptive thresholds than those whose parents were both non-lame birds. These findings may guide deeper investigation into phenotypic lameness resilience, nociceptive thresholds, pain processing, and chronic pain-induced analgesia in industrial poultry.