Scanning is used to identify multiple pregnancies to better manage twin bearing ewes and to identify and remove barren ewes. Careful consideration needs to be made of the costs and benefits of pregnancy scanning to achieve a management and economic gain in the breeding ewe enterprise.
Skilled contractors can scan ewes to age the foetuses either in the first or second cycle. This information can be used to better allocate feed for pregnant ewes and limit the number of ewes in lambing paddocks at one time.
Benefits of Pregnancy Scanning |
Disadvantages of Pregnancy Scanning |
More precise flock and lambing paddock management |
More mobs to manage and stress of extra handling in some seasons |
More targeted use of feed supplements when economically justified or allocation of dry, single bearing and twin bearing ewes to appropriate feed resources |
More labour intensive when scanning and managing for multiple births |
Targeted management (more shelter and privacy) of twin bearing ewes to protected paddocks to improve lamb survival
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Potential for mismothering when twinning mobs are run together under high stocking rates at lambing |
Non-pregnant ewes can be run as dry sheep for wool production or culled and sold if feed resources are limited |
Late lambing mob to manage where dry ewes are rejoined and the normal breeding cycle on the farm is disrupted |
Basis for careful fodder budgeting and forward planning of pasture utilisation to achievehigh reproduction rates and/or target markets |
Potentially an additional and unnecessary cost in low twinning flocks |
Likely to be most cost effective in drought years or when ewes are mated at low condition score and maidens at low body weight |
More precise management required and this may compete with other farm operations |
Twins can be managed with better pasture in lambing mobs with a high proportion of twins. They can be run in protected where twins are separated there could be a saving in supplementary feed costs |
Opportunity cost of scanning and extra labour |
May identify where reproductive losses are in the breeding cycle |
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