Studies on Ante- and Post- Mortem Lesions as Animal-Based Criteria to Improve Pig Welfare and Meat Quality in Swine

Abstract

The study of lesions as animal-based criteria on pigs is of increasing interest at both research and industry level. Lesions are important outcome measures, able to detect when animal welfare is suboptimal. The presence of lesions is also correlated to a lower quality, and thus to a loss of profits, in the derived products. This manuscript is composed by two studies investigating the use of lesions as suitable indicators of welfare level and meat quality at both farm and slaughter level. The first study, performed in Italy, studied the effect of different environmental enrichment devices provided to Italian heavy pigs (intended for the production of Parma Ham PDO) on the occurrence of skin, tail and anatomopathological (e.g. oesophageal gastric lesion) lesions, on carcass traits, meat quality and long-dried products. The tested devices were: hanging chains, wood-log inside a metal racket, edible block inside a metal racket. Results showed an increased tail score in the wooden enrichment, united to a higher F-o-M and a lower backfat thickness in the carcass, and to a lower water holding capacity of the meat. The edible block has not presented changes in skin and tail score, while an increased number of oesophageal lesion score was observed, which did not affect carcass and derived products. The second study was conducted in Canada. It aimed at assessing the age of the lesion on pig carcass at slaughter through the use of a spectrophotometer and biological indicators (i.e. gene expression, histochemistry, histology) on skin samples analyzed in the laboratory. Results demonstrated that spectrophotometric color assessment is a suitable method which allows to discriminate between fresh lesions (occurred pre-slaughter) and older lesions (on-farm). The results were also comparable with what was obtained from the expression of some tested genes and from inflammation scores assessed through histology.