Interactions between heredity and environment in the Australian Merino. I. Strain X location interactions in wool traits

Abstract

An experiment is described in which five strains of the Australian Merino were run as breeding groups over a number of years in three wool-growing regions. Strain x location interactions were estimated as indicators of adaptation of specific strains to particular environments. The results of the experiment are presented for measurements of greasy fleece weight, clean fleece weight, percentage clean scoured yield, number of fibres per unit area of skin, number of crimps per inch of staple, fibre diameter, and staple length, and for gradings of count (quality number), character, colour, soundness, and handle. Real interactions were found in most of these attributes but they were generally small and accounted for only a minor fraction of the variance. Inconsistency of the interactions in a particular trait may be due to climatic variability from year to year at individual locations. It appears that specific adaptations in these characteristics should not be an important reason for the choice of the strain of sheep to be used in particular areas.