THE EFFECTS OF SELECTION FOR LEAN GROWTH AND THE HALOTHANE ALLELE ON CARCASS AND MEAT QUALITY OF PIGS TRANSPORTED LONG AND SHORT DISTANCES TO SLAUGHTER

Carcass and lean quality traits were studied in two genetic lines of pigs in which the halothane allele n was segregating with the normal allele N. One line had been selected for high growth rate and low backfat depth and the other line maintained as an unselected control. Pigs of the three segregants NN, Nn and nn from both lines were grown at two locations, one near the abattoir (1 h by road) and the other far (10 h) from the same abattoir. Pigs from both locations were fasted for 20 h before slaughter. Relative to control line pigs, those from the selected line had lower backfat depths, greater ham weights, eye muscle areas and carcass lengths but lower dressing percentages. The n allele had little effect on carcass traits but for lean quality traits, the n allele acted additively to increase acidity, paleness, water lost through drip, centrifugation and cooking and to reduce cured yield. Independently of the n allele, selection for lean growth increased the incidence of dark, firm and dry (DFD) pork. This was highest in carcasses of NN pigs from the selected line grown far from the abattoir. nn pigs from the control line grown near the abattoir produced the most pale, soft, exudative (PSE) pork.