Selection for high and low ratio and high and low primary density in Merino sheep

Abstract

The result of selecting sheep up and down for secondary to primary follicle ratio (S/P) and up and down for the number of primary follicles to the square millimetre is examined from the point of view of Fraser's theory of competition between follicles. The possibility of finding other characters in which variation will cause variation in fleece weight has also been investigated. It is concluded that selection which increased the S/P ratio and primary density did not increase fleece weight; follicle depth is possibly one skin character which, when changed, causes changes in fleece weight but this requires confirmation.