Pre-slaughter factors that influence the occurrence of skin lesions in pigs - a cross-sectional study

Abstract

Skin lesions are iceberg indicators of animal welfare. The study of the bruises in pig carcasses allows the inference of how and when a traumatic moment that resulted in the injury occurred, as well as its severity. A cross-sectional study to investigate the association between pre-slaughter factors and the type of skin lesions in cross-breed fattening domestic pigs was performed on 300 pigs slaughtered in a slaughterhouse in Northern Portugal. Data on the sex of the animals, animals? origin, transport time and lairage time were collected. Skin lesions were evaluated according to location (region) on the carcass, shape, size, number of lesions per region and lesion age (colour). Descriptive, univariate and logistic regression analyses were performed (considering p?0.01). A total of 468 injuries were recorded, distributed by different carcass regions. Most of these injuries occurred on the back (37.2%) and temporally close to slaughter (94.2%). Castrated males were more predisposed to present bruises probably related to fights between animals. Females and animals subjected to longer transport times were more likely to have skin lesion injuries resulting from poor handling. The study highlights the importance of regular monitoring of welfare indicators in a pre-slaughter context for more efficient surveillance of animal welfare.