Genetic parameters for osteochondrosis traits in elbow joints of crossbred pigs and relationships with production traits

Abstract

AbstractA total of 9360 offspring of 12 purebred Duroc sires and 692 Landrace × Yorkshire sows were evaluated for six osteochondrosis traits in the left elbow joints at slaughter. Osteochondrosis traits, growth pre- and post weaning, and meat content at slaughter were analysed simultaneously by a multivariate genetic model. Castrates scored worse than female pigs for nearly all osteochondral traits. Heritability of elbow osteochondrosis was moderate (0·02 to 0·28) and, thus, selection against the disorder is possible. Phenotypic correlations among joint surface abnormalities, cartilage thickness, subchondral lesions and cracks in the cartilage at the osteochondral junction in the medial condyle ranged from 0·33 to 0·69, whereas genetic correlations ranged from 0·75 to 0·97. Phenotypic correlations of the sagittal central groove with other abnormalities in the medial condyle were low and insignificant but genetic correlations were strongly significant (0·66 to 0·77). Depression of the proximal edge of the radius was to some extent phenotypically correlated to abnormalities in the medial humeral condyle (around 0·2), while genetic correlations ranged from 0·05 to 0·52. Significant genetic correlations among osteochondral traits indicate that all are part of the osteochondrosis complex. Abnormalities in the joint surface showed the strongest genetic correlations with other osteochondrosis variables in the elbow joint and were moderately inherited (h2= 0·22), which indicates that this trait can be used as a marker to select against osteochondrosis. Osteochondral traits had no significant genetic correlations with growth to weaning and to 30 kg, slight negative (favourable) genetic correlations with growth from 30 to 100 kg, and slightly positive (unfavourable) genetic correlations with meat content in carcass.