Some aspects of the efficiency of large-scale artificial insemination operations in sheep

Abstract

The problems of estimating each day the proportion of ewes coming into oestrus for the first time and the proportion of ewes not returning after the first service have been investigated and discussed in relation to large-scale artificial insemination operations. The results of these theoretical studies were used to examine data from more than 700 Merino ewes which had undergone artificial insemination, and evidence of inefficiency due to an early failure of vasectomized rams was found. From subsequent analyses it was concluded that the methods developed in this paper for estimating conception rates were fairly sensitive and produced satisfactory results.