Measuring foetal loss with real time scanning.

Abstract

We are currently examining wastage rates in several flocks of varying fecundity. Merino A flock consisted of approximately 500 ewes run at Tamworth, NSW in 1981 and 1982 (3 and 4 years old respectively). Merino B flock 1981 was the group of 33 mixed age Booroola ewes previously reported (Wilkins et al. 1982). Merino B flock 1982 was a group of 69 mixed age Booroola ewes. Merino C flock 1982 was a group of 59 non-Booroola contemporary controls, joined and run with the Booroola ewes. Flocks B and C were run at Armidale, NSW. Dorset flock 1982 was a group of 89 adult ewes run at Cowra, NSW. All flocks except the Dorset underwent laparoscopy at the cycle of mating to determine individual ovulation status. The first observation on the Dorset flock was by laparoscopy at 30 days to assess pregnancy status. The fate of ova shed by each ewe was followed by scanning at various stages to determine numbers of foetuses present and by observing lambs born. A summary of these results is shown in Table 1.