The average lambing performance of Western Australia\u27s ewe flock fluctuates between 60 and 70 per cent. Although this level of performance and variation between years is important for the sheep industry, individual farmers are more concerned about performance of their own flocks.
Figure shows the range in lambing performances that exist between farms in this State in 1983-84. The seriously poor performance of many flocks is apparentm - 28 percent of farms had less than 60 per cent lambing. By contrast, 24 farms had performances better than 100 per cent. The reasons for the large differences between farms ( and between years for each farm) lie in the nimber of eggs a ewe sheds at mating, and the wastage that follows through to lamb marking.
This review examines the source of reproductive wastage in the ewe. It establishes the importance of the research outlined in the following three articles to improve the performance of ewes