Interactions between heredity and environment in the Australian Merino. II. Strain x location interactions in body traits and reproductive performance

Abstract

Further results are presented of an experiment in which five strains of the Australian Merino were run as breeding groups in three wool-growing regions. Strain x location interactions were estimated as indicators of adaptation of specific strains to particular environments. The characters for which results are presented here are measurements of body weight, body length, width of hips, width of shoulders, depth of chest, and length of fore leg, gradings of skin folds on the neck and body and of face cover, and finally number and weight of lambs born and weaned.

Real interactions of strain and location were found in most of these attributes, but they were generally of moderate to small size and accounted for only a minor fraction of the variance. Frequent year x location interactions may account for the unimportance of strain x location interactions. In these characters, as in wool traits, it appears that specific adaptations are not important in the choice of the strain of sheep to be used in particular areas. In feproductive traits, strain differences are of small importance in contrast to marked and consistent differences between strains in other attributes.