Abstract

Techniques of real time ultra sound (ADR 2130), Toshiba Sonolayer-L SAL 22A) and radiography (DSIR X-ray) were assessed to determine the accuracy of identifying ewes carrying 3 or more lambs. Ewes were scanned between 62 and 75 days of gestation with ultra-sound and between 110 and 124 days with X-ray. There were 94.2% (ultra- sound) and 96.2% (X-ray) of ewes predicted to be carrying 3 or more lambs that actually lambed with 3 or more lambs. However, 21.1% (ultra-sound) and 8.4% (X-ray) of ewes which lambed with 3 or more lambs were predicted to lamb with<3 lambs. Because ultra-sonic diagnosis is carried out at an earlier stage of gestation it gives greater flexibility to apply nutritional management to ewes carrying 3 or more lambs in order to sustain foetal growth in these high litter sizes.

JC, McEwan, CD Mathieson, and H Hawker

Proceedings of the New Zealand Society of Animal Production, Volume 45, , 147-150, 1985