THE GROWTH-PERFORMANCE, CARCASS CHARACTERISTICS, AND MEAT QUALITY OF HALOTHANE CARRIER AND NEGATIVE PIGS

Growth performance, carcass characteristics, and meat quality of halot hane carrier (Nn) and negative ( NN) pigs grown from 40 kg live weight and slaughtered at three weights (110, 125, and 140 kg live weight) w ere studied. Daily gains were similar for the two genotypes (974 g for Nn and 964 g for NN), but Nn pigs had a higher gain:feed ratio than N N pigs (P <.01). Dressing percentage was higher in Nn pigs than in NN pigs (P <.001), but there were no genotype differences for carcass len gth, backfat thickness, or loin eye area. Percentage yield of trimmed, boneless wholesale cuts was higher for Nn pigs than for NN pigs (P <. 05). This resulted from higher trimmed, boneless ham, boston, and picn ic weights (P <.05) in Nn than in NN pigs (6.9, 3.2, 3.5 kg vs 6.6, 3. 0, 3.4 kg, respectively). The weight of fat-free lean was higher in Nn pigs (P <.05). The longissimus thoracis muscle from carrier pigs had lower 45 min (P <.001) and 24 h (P <.01) pH. Longissimus lumborum samp les from carriers had lower (P <.001) subjective meat quality scores a nd a higher drip loss (P <.001); however, cooking loss, eating quality , and shear force values were similar for the two genotypes. There wer e no important slaughter weight x genotype interactions for the traits reported. Overall, the data from this study suggest Nn pigs had an ad vantage over NN pigs in terms of feed efficiency, carcass yield, fat-f ree lean content, and commercial lean cut yields, but had a higher inc idence of PSE.