title: Reproductive performance of Polwarth and Corriedale sheep in Tasmania.
abstract: The reproductive performance of 27 Polwarth and 9 Corriedale flocks was studied under commercial conditions in Tasmania. Mean ovulation rate was 149% but the mean number of lambs marked per ewe joined was only 88%. The major sources of wastage contributing to the overall loss were identified as an 18% loss of embryos in twin-ovulating ewes which gave birth to only one lamb, and a mean perinatal lamb mortality of 21% of lambs born. There was no significant difference in embryo survival between unilateral and bilateral twin-ovulating ewes.
authors.affiliation: Department of Agriculture, Launceston, Tasmania, Australia.
authors.forename: C F
authors.initials: CF
authors.lastname: King