Genetic, phenotypic and environmental correlations among performance traits estimated from Limousin field data.

Field records from the North American Limousin Foundation performance testing program provided three data sets for the estimation of genetic, phenotypic and environmental correlations among several performance traits. The traits were: birth weight, preweaning average daily gain, adjusted 205-d weaning weight, postweaning average daily gain, adjusted 365-d yearling weight, weight/d of age, preweaning relative growth and postweaning relative growth. Birth weight had a positive genetic relationship with all measures of growth except pre- and postweaning relative growth. The genetic relationship between preweaning relative growth and birth weight was small and negative. Postweaning relative growth had little genetic relationship to birth weight. The genetic relationships among the various growth characteristics were positive, except for those involving pre- and postweaning relative growth. Postweaning relative growth was negatively associated with preweaning average daily gain and adjusted 205-d weight. Preweaning relative growth had little genetic association with adjusted 205-d weight, adjusted 365-d weight or weight/day of age.