Carcass Lesion Severity and Pre-Slaughter Conditions in Heavy Pigs: A Prospective Study at a Commercial Abattoir in Northern Italy

Pre-slaughter conditions and their effects on carcass quality have been largely addressed for pigs of 90-100 kg live weight, while few studies consider the effects of pre-slaughter conditions on the quality of the carcasses obtained from heavy pigs intended for Protected Designation of Origin (PDO) production. A total of 1680 heavy pigs were transported in 72 batches from a farm to a commercial abattoir on 16 different days, avoiding mixing unfamiliar animals. Slaughterhouse conditions, animal behaviors, and human-animal interactions were annotated at unloading and during the race toward the stunning cage. Carcass lesions on the rear, middle, and shoulder parts of the carcasses were scored. The prevalence of carcasses with severe lesions was 6.92%, 11.87%, and 6.83%, for the rear, middle, and shoulder parts, respectively. Among the pre-slaughter events, waiting before unloading and improper handling practices at the abattoir were the major factors affecting carcass lesion severity. Lairage pen space allowance was also found to affect severe rear and shoulder lesions, and the batches that were transported in the trailer had an increased prevalence of severe shoulder lesions. Our results suggest waiting time before unloading should be shortened as much as possible, and educational programs to train operators for more careful management of animals in the abattoir are greatly required to avoid improper animal handling practices.