Tuesday, February 23, 2010

Scanning Data

We thought this information might be of interest to some regarding our recent scanning done here at Premier.

Ultra-sound testing conducted by a contractor with a long history of skill.

North farm.
196 ewe lambs exposed to 7 Dorper/Romanov rams in Dec 1 to Jan 15. 75% of lambs are Border Leicester/Ile De France/Romanov/Dorper, 25%Katahdin/Romanov/Dorper. Lambs born on April and May.
- 93% are pregnant
145 singles
37 twins
14 open.
This was a good result for lambs of this age, size and genetic makeup.

Home farm.
126 ewes (Border Leicester/Ile de France) were exposed in Nov. to lamb in Mar./April. Most of these are were too far along in gestation (110 days) for a fetal count to be truly accurate. We will shed lamb this flock.
94% pregnant. This is lower than the norm for this type of ewe at Premier. However 8 open ewes included culls from last year that were retained to allow us to conduct marking paint trials. If these were excluded the pregnancy % is acceptable.

East farm.
190 ewes exposed in Dec to Dorper/Romanov rams. Ewe genetics- a mix of Dorper, Romanov, Katahdin, Border Leicester genetics. Some are 100% hair ewes in appearance. Others appear 100% wool and are more than 60% Border Leicester.
- 97.5% pregnant.
45 singles
120 twins
20 triplets (perhaps 1 of these w. 4)
5 not pregnant

While the % pregnant was very good we were not happy to learn that so many ewes were singles. We suspect that the "single" ewes are those with a high % of Border Leicester genetics as we know, from prior results, that these ewes have many more lambs/ewes if exposed in October than December.

It's our intent to lamb these on pasture with minimal attention. (it's an experiment). We can't do this in SE Iowa until May. One negative aspect of this system is that, because the ewes are left alone from May 1 to June 10, we can't know which ewes had more twins vs singles vs triplets. Ultrasounding solves this. It allows us to separate the ewes in advance of lambing according to fertility and to keep them separate during lambing. We propose to cull the less prolific ewes and avoid retaining their lamb-and by this method trend toward a more prolific, aseasonal ewe flock.