Birth weight and weaning weight records were availablefor all breeds. However, pre-weaning weights were available for only the Ile de Franceand Merino Landsheep breeds, while post-weaning weights were available only for theDormer breed. Direct heritability estimates (h2) derived using single-trait analyses were0.25, 0.28 and 0.37 for birth weight, weaning weight and post-weaning weight respectivelyfor the Dormer breed.