The effect of breed-production systems on the myosin heavy chain l, the biochemical characteristics and the colour variables of Longissimus thoracis from seven Spanish beef cattle breeds

摘要

The effect of breed-production system on the myosin heavy chain l (MHC-l), the biochemical characteristics and the colour variables of longissimus Thoracis (LT) from seven beef breeds was studied f Asturiana de la Montafia (AM), Asturiana de los Valles (AV), Avilefia-Negra lberica (A-Nl), Bruna dels Pirineus (BP), Morucha (MO), Pirenaica (PI) and Retinta (RE) (Age at slaughter between 368 and 54l days; carcass weight between 249 and 334 kg). Significant differences between breed--production systems were found for all traits evaluated. LT from the MO, a rustic type breed, was the most oxidative (MHC-I. 39.3/100. isocitrate dehy- drogenase activity, 52 nmol min~-l mg~-1, pigment content, l88.4 μg acid haematin g 1) and showed a low L* value (32.6) and high a* and C* values (24 and 27.2, respectively). In terms of meat colour (L* and a*) the canonical discriminant ana1ysis separated the breeds into two groups, the AV, the PI and the A-NI (the lightest ones) from the AM and the MO breeds (the reddest and darkest) whereas the BP showed an intermediate position. The RE and the A--NI were distinguished from the others by their high intra- muscular fat content. Meat colour was affected by the muscle biochemical traits in the breed-production systems studied.