The association between neck wrinkle and fertility in Merino ewes in south-western Australia

Abstract

A flock of 920 Merino ewes was divided into three classes on neck wrinkle, and these were subdivided into two face-cover classes. The wrinkly classes were typical of Merino ewes in the Great Southern region of West Australia, and the remainder were plainer. The ewes were mated together and grazed together until late pregnancy. They were classified into neck-wrinkle and face-cover classes eleven days before lambing, and grazed separately during lambing. The ratio of lambs born: ewes mated was 69 per cent in the wrinkly groups (453 ewes), 89 per cent in the intermediate groups (396 ewes), and 84.5 per cent in the plain groups (71 ewes). The variation due to wrinkle was highly significant.