Carcass characteristics and meat quality of halothane negative and halothane positive pietrain pigs

One hundred and seventy-six Pietrain pigs were tested for halothane sensitivity by means of a 5-min halothane anaesthesia in two experiments. One hundred and twenty were halothane negative (HN) and 56 were halothane positive (HP). In one experiment pigs were slaughtered under commercial (stress) conditions; in the other experiment pigs were killed under minimal stress conditions. The carcasses of HP pigs were meatier and shorter and contained 2·2% more muscle than the carcasses of HN pigs. Halothane positive pigs gave a meat of poorer quality, as assessed in the fresh state. When the pigs were slaughtered under commercial conditions, hams from HP pigs were not inferior in curing ability and had a higher total processing yield of Paris ham due to their higher trimming yield. When the pigs were killed under minimal stress conditions, there was no difference in the total processing yield betwen HN and HP pigs, because the technological yield was markedly reduced in HP pigs. However, in both cases, HP pigs produced more cooked ham per pig. It is suggested that different physiological mechanisms may account for either PSE (pale soft exudative) or DFD (dark firm dry) meat. The former is the consequence of an excessively high rate of post mortem glycolysis which is clearly manifest in HP pigs when they are killed under minimal stress conditions and the latter appears to be unrelated to halothane sensitivity as the ultimate pH of HP and HN pigs is similar when the animals are slaughtered under stress conditions.