Effects of the MHS locus on growth, carcass and meat quality traits in F₂ crosses between Mangalitza and Piétrain breeds

Abstract. A total of 345 F₂ animals from a crossbred design Mangalitza (homozygous NN) x Piétrain (homozygous nn) were fed ad libitum at the institute's Thalhausen Research Station and slaughtered at a live weight of approximately 100 kg. MHS genotypes (67 nn, 192 Nn and 86 NN) were determined directly in a DNA test targeting the ryanodine reeeptor locus. Models for analysis of variance included sire, dam, pen, slaughter group, sex and MHS effects. Growth Performance was generally lower and carcass composition minor compared to other breeds and crosses. No significant differences were found between MHS genotypes for growth traits but NN animals tended to be less eflicient with respect to food conversion. However, nearly all measurements of the carcass showed significant differences between nn and NN which were especially pronounced for sidefat thickness (−7 1mm) fat over the musculus longissimus dorsi (−8.8 mm) and loin eye area (+8.7 cm²) as well as fat area (−5.1 cm²) We found Nn animals performing similar to NN animals due to incomplete dominance of the N allele. As expected nn had a substantial negative influence on meat quality compared to NN and Nn (e.g. −0.61 and −0.15 for pH 45 min, respectively). Intramuscular fat content was at a high level and nn had significantly lower values with differences of −0.40% and −0.25% relative to NN and Nn, respectively. A whole genome scan is currently underway with emphasis on fat measurements which showed promising Variation in this study.