Selection for reduced muscle glycolytic potential in Large White pigs. II. Correlated responses in meat quality and muscle compositional traits.

摘要

From a base population of French Large White pigs, presumably free of the HALn and RN- alleles, 2 lines were formed: a randombred control line and a line selected for reduced in vivo glycolytic potential (IVGP) of the longissimus. During the 6 generations of selection, second-parity animals were slaughtered at 100 kg body weight to evaluate correlated responses in meat quality and muscle composition. Heritabilities (h2s), genetic correlations and average genetic trends per generation were estimatedfor all traits. Heritabilities varied among muscles. Within muscle h2 estimates for ultimate pH and lightness L* value were of the same order. For enzyme activities, h2s were 0.12-0.44 for lactate dehydrogenase (LDH), 0.22-0.44 for citrate synthase (CS)and 0.06-0.26 for the LDH/CS ratio. Heritabilities for longissimus composition traits were 0.33-0.59, except for nitrogen content. The h2 for technological yield of cured-cook ham processing was 0.32±0.09. Most physiological and chemical characters of the longissimus were not significantly affected by selection. No genetic change was found for technological yield, though this trait was genetically correlated with IVGP (-0.42±0.12). There were significant genetic trends for longissimus enzyme activitiesand fibre characters in the selection line, indicating that this line had more glycolytic muscle metabolism, a lower proportion of oxido-glycolytic fibres, a higher proportion of glycolytic fibres, a higher LDH/CS ratio and a lower haem pigment contentthan the control line.