You can use ultrasound or the BioPRYN blood test to for pregnancy testing in sheep. The benefit of ultrasound is that you can see how many lambs you have in addition to knowing if they are pregnant or not, unfortunately it is more expensive too. The BioPRYN test only tells you pregnant or not, but also is a less expensive option. For this year we decided to go with the BioPRYN test. We ordered them through DHI Cooperative for $2.40 per test, blood collection supplies included.
For accurate results the ewes must be at least 30 days bred. We had 3 breeding groups and left the rams in for 34 days, after that we put all the ewes together and left the young ram in for another 17 days. We pulled blood 30 days after taking the young ram out. The ewes would be between 30 to 81 days bred. Something I did not consider, having drawn a lot of blood over the summer, is that you cannot see the veins with the thicker hair coat in the winter. You can still feel it easily though, just need to work on feel, rather than sight.
This is our first year breeding our ewe lambs to lamb at one year old. At first we were only going to check the ewe lambs so we can make sure to give special feed and attention to the bred ones. Later we decided to check everyone as we would spend more money feeding them through the winter compared to the cost of the test. That way we can cull unbred ewes now rather than waiting until lambing to see that they are open.
We mailed in the blood samples on Monday and received the results on Thursday via e-mail. The result comes back as a number (level of pregnancy specific protein B in the sample). The lab gives you a reference range for open (not bred), low re-check (likely not pregnant but borderline, so check again in a few weeks), high re-check (likely pregnant but borderline, so check again in a few weeks) and pregnant. All but one of our sheep came back as pregnant, with levels significantly higher than the cut off for pregnancy. The one ewe lamb that came back open has a really low level so I am confident that she is open, no need to re-check.
With the good also comes the bad, we anticipated that the test would pay for itself with the feed we would be saving by culling early and not having to feed the good stuff, this obviously did not work seeing that all but one came back pregnant. We will most likely not test the whole flock again next year. We are very grateful that all our adult ewes and all but one of our ewe lambs came back as pregnant. Very glad to see that the boys could get the job done and that the ewe lambs are fertile at a young age. Now we are just anxiously waiting for lambing to start at the end of March.