Monday, 21 June 2010

Pregnancy Testing the Ewes

On Thursday 10th June 2010 Andrew Naylor from Canowindra came and pregnancy-tested our older ewes. There were several reasons why we wanted this done:
  1. It would provide us with an indication of how well the ewes were travelling health-wise under our management.
  2. It enables us to identify those that are not pregnant. We see little point in carrying 'breeding' ewes that don't in fact breed. Culling them sooner rather than later is in our view better all round in that we realise the cash from the sale, have less animals to manage, and have more grass available for the rest of the mob.
  3. By identifying single and multiple embryos we can forecast how many lambs are likely to be 'on-ground' when it comes time to do the marking.
  4. Had we decided to brand those with multiple embryos we then would have had the option of separating them out and giving them access to better feed which in turn increases their prospects for taking the multiple lambs through to weaning. We did not do this because our flock size is not large and our intent is to give all of the ewes access to the best of our feed.
  5. Our joining period was the bare minimum at 35 days (2 full cycles) and if the pregnancy percentage proved to be very low we would have the option of putting the rams back in with the ewes or maybe even getting other rams for the job.
The pregnancy test involves placing an ultra-sound device just near the front of the udder area and identifying from the connected display screen whether the ewe is pregnant or has multiple embryos. In the photo you can see the mini-tent that Andrew places over himself and the equipment. It is positioned at the end of the drafting race enabling us to more easily run the sheep up the ramp and into the crush where each ewe is individually held while the scanning is carried out. The process is very quick at in excess of 200 per hour, although we understand the throughput rate may have been 300 an hour had we been better at pushing up the ewes into the scanning structure i.e. the weak-link was our ability to herd the sheep.

We were pleased with the results (3% 'empty', 37% singles and 60% multiple) and found Andrew great to deal with. No fuss - and his system for setting up, using and removing his equipment was excellent.

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