Effects of pre-slaughter transport, lairage and sex on pig chemical serologic profiles.

Abstract

The aim of this research was to study the effects of pre-slaughter transport and lairage on th e chemical serologic profile of swine, as well as its relationship with qualitative aspects of meat: pH, color and temperature. Forty eight Pietrain x Landrace pigs were monitored (24 females and 24 barrows). They were transported on straw bedding trucks without stops during 2 h and deprived of feed and water. Blood samples were taken before loading, at arrival to the slaughterhouse, after lairage and during bleeding (20 sec after they were electrically stunned). At arrival to the slaughterhouse pigs were randomly distributed in 4 groups: Rested (n = 24) non-rested (n = 24) these groups were also divided by sex. Blood samples were taken form groups 1 and 2 and the animals sent directly to the slaughter pens, whereas groups 3 and 4, after blood sampling, were taken to lairage pens. Glucose and Creatine Kinase (CK) showed a high increase in blood concentration, associated to an increase in muscular activity and a decrease in globulins concentration as a consequence of stress and immunosuppres sion. Hyperglycemia and lactic acidosis detected in animals without rest were statistically different (p<0.05) compared to the group that rested. Bicarbonate level significantly decreased (p<0.05) in non-rested animals as compared to rested animals. Results indicated that animals without rest before slaughter can show hemodynamic and metabolic alterations that lead to hyperglycemia, lactic acidosis and an abrupt descent of pH, altering the carcass color.