Effects of the halothane genotype and slaughter weight on texture of pork

The objective of this study was to investigate the effects of the halothane (HAL) genotype, slaughter weight (SW), and the HAL x SW interaction on com positional and textural traits of raw and cooked pork. Pigs were bred to ex hibit one of the three HAL genotypes (NN, Nn, and nn) with otherwise equiva lent genomes. The nn halothane reactors are known to typically produce PSE pork, whereas NN pigs do not typically produce PSE pork. Pietrain x Large W hite gilts and boars, all with verified Nit genotype (by DNA test), were ma ted to obtain F-2 littermates of the three NAL genotypes. These pigs were s laughtered at either 101 +/- 3 ("light") or 127 +/- 3 ("heavy") kg BW and w ere evaluated for longissimus muscle traits. The pH at .5 h after death (pH 1) was 6.35, 6.13, and 5.68 in NN,Nn,and nn pigs, respectively. Sarcomere l ength was greater in nn than in NN and Nn pigs (1.94 vs 1.83 and 1.85 mu m, respectively). Mechanical resistance was higher in nn than in NN pigs for both raw and cooked meat. Meat from nn pigs was judged by a trained panel t o be less rough, more cohesive, harder, more fibrous, less granular, more e lastic, and less easy to swallow than meat, from NN pigs. For most traits u nder study, the heterozygotes were intermediate between the homozygotes but closer to NN than to nn pigs. Muscle from heavy pigs had longer sarcomeres and less moisture than muscle from light pigs. The n allele of the HAL gen e unfavorably affects pork texture, and this effect is maintained throughou t the range of 101 to 127 kg BW.