An Inside Perspective: Ultrasound Pregnancy Scanning of Sheep


We have shared a little in the past about ultrasound pregnancy scanning our sheep. We were doing a group of 280 ewes last month and I wanted to post a little more information about it here. My goal is to share a little of my experience with you in the form of a few practical tips. If you are interested in learning to preg-check your own sheep, hopefully this is helpful to you.


Just a note on the situation here in Alberta to give context. In Alberta, only veterinarians can diagnose pregnancy in sheep professionally. However, because of the relatively small number of sheep in this part of the world, few vets are available to perform this service, and their fees would usually be too expensive. I have also never heard of a vet that can count fetuses. The result is that most sheep farms that are large enough are purchasing their own entry level ultrasound machines and simply checking for open ewes. That’s what I will be talking about in this post.


Though it would be great to be able to count lambs, there is significant enough benefit in preg checking alone to be worth the work and investment. For example, you have the benefit of being able to pull open ewes out of the group before expensive late gestation rations start. If you do multiple lambing groups you may be able to try re-breeding open ewes for a later lambing. It may also allow you to make a culling decision a few months earlier than you may have otherwise. It can be especially valuable in groups of ewe lambs which typically have lower conception rates.


Now for the practical tips.

1- Make sure the ewes are off feed 24 hours before scanning. A full gut makes it more difficult to see.


2- Your arm will be right between their back legs, so you’ll want some protective gear. A vet showed me this trick. OB glove for coverage with a latex glove overtop to make it easier to use your fingers.



3- Put your ultrasound gel into a dish. This way you can dip your probe rather than having to squirt some on the probe every time. This is much quicker and less wasteful. It doesn’t necessarily require much gel, so use it sparingly. Too much just makes a slippery mess.

4- Some kind of working chute is preferable for more than a few ewes. I’ve worked in a chute where I had to climb in behind each ewe and kneel in the chute. It worked, but it was hard on the knees, back and shoulder. Our Racewell sheep handler is ideal. It holds the ewe elevated above floor height, so that, when I’m sitting in a chair alongside, the ewe’s belly is right at a comfortable height. You’ll see in the photos how I catch the sheep far enough back in the squeeze so that her back end is exposed. I’ve seen some chutes were the technician has a space where they can reach through the side of the chute.



5- Place the probe on the ewes belly where you find the bare skin inside the left hind leg and beside the udder. I generally point the probe toward the spine and angled a bit forward. You’ll get the feel for where you need to be with a little practice.


6- Pregnancy is usually very easy to detect. Take a look at some of these screen shots to see what you are looking for. If you’re not getting a clear image try using a little extra gel. Sometimes there is a bit of buildup on the ewe’s skin that needs to be cleaned off first.


There’s a lot more I could say, but I’ll leave it at that for now. If you have any questions just ask.

Advertisements

Counting Lambs Before They’re… Hatched?

Well, it’s now confirmed that about 400 ewes will be lambing here through February and March.  Yesterday was a full day of running our first breeding group through for ultrasound preg-checking.  We’ve been ultrasounding our own ewes now for a number of years and, though it is a big job, we find that it really pays off pretty quickly.  It allows us to identify our open ewes and, either give them another chance to breed, or identify cull ewes sooner than otherwise.  It also means that we aren’t feeding several open ewes all the way through late gestation and lambing rations, which is costly enough for pregnant ewes.

IMG_8294[1]

We have been using a small portable ultrasound unit from Intriquip.  It’s about the perfect balance between cost and performance for our operation.  We use it simply to identify open and pregnant ewes.  As much as I would like to be able to count the number of lambs per ewe, it would require much more experience and training on my part and probably a more expensive ultrasound unit. IMG_8288[1]

 

IMG_8289[1]We were thankful to have Connor and Brayden Pearson join us for the day.  Once again they blew me away with their industriousness, and we managed to get through the whole group of a little over 400 ewes. IMG_8293[1]

 

Overall everything went very smoothly.  Brayden got to put our new alley system to the test while he ran the ewes up to us.  The night before last, I finished building and installing two guillotine gates in our curved lead up alley.  The idea was to be able to keep small groups of ewes moving up the alley in a way that they could always see sheep ahead of them.  To accomplish that, I used some pieces of overhead door panel for the bottom portion of the gates.  They are nice and light weight and don’t have spaces where sheep can stick a leg through and get injured.  The top portion of the gates is a panel made of galvanized steel rods.  The sheep can see through this part of the panel to the next pen ahead of them.  Sheep love to follow other sheep and it helps them move up the alley when they feel they are following rather than leading.  I ran cables up through a pulley and across the handling pen then through another pulley and across over top of the squeeze.  The plan was that the gates could be raised from either position.  It seems like the design worked, because Brayden didn’t seem to have much trouble keeping us supplied with ewes nonstop all day!  I’m thinking that the only change I will make is to add a counterweight to the lift cable so that the gates can be lifted a little bit more easily and quickly, but so far so good!IMG_8292[1]

 

IMG_8295[1]Meanwhile on the front end I was doing the ultrasound scanning while Connor recorded tag numbers and pregnancy status in the handheld.  We also decided to give these ewes their dewormer while we were handling them, and Connor took care of that while I was busy scanning.IMG_8290[1]

 

This is one job where I am extremely thankful for our Racewell Superhandler squeeze.  It works perfectly for ultrasounding.  What I do, is set the ‘eyes’ to catch the ewes early so their back end is hanging out of the squeeze nicely.  This gives me good access for scanning while keeping them restrained.  It is also very nice to have the ewes up off the ground so I can sit in a chair rather than squatting all day. IMG_8296[1]

 

Ultrasounding ewes is done externally between the left hind leg and the udder.  With a bit of practice most pregnant ewes are fairly quickly identified and the process moves along nicely.  Some ewes seem to require a little more probing around to determine.  The ones that I find most difficult are the open ewes.  Probably because it’s a difficult search when you’re looking for something that’s not there.  I usually spend a fair bit longer on ewes where nothing is immediately visible.  Sometimes it turns out that she is pregnant, sometimes my searching yields no results.  In that case she gets a pink mark and goes into a separate pen.  In our flock, I will wait a few days and re-scan the ‘open’ group of ewes just to make sure that they are all actually open.  At that point I can make a culling decision.  If a ewe is one of our lower producers and is now open, then it’s a good opportunity to ship her.  If she’s normally a good ewe and just didn’t take for some reason, then she will go in with the next breeding group and get another chance in a month or so. IMG_8297[1]

 

Ultrasounding sheep isn’t all that common in Alberta yet.  Likely because the vet association won’t allow technicians to offer the service, as it is technically a veterinary diagnosis.  If you are a mid to large sized flock owner it might be something that you want to look in to.  The cost of the equipment probably doesn’t make sense for anyone with a smaller flock, though several small producers might want to have joint ownership in a unit or some such arrangement.  If you are interested in learning more about ultrasound scanning sheep let me know and I can try to answer any other questions that you might have.

 

Next on the road to lambing will be shearing.  Stay tuned.

 

-Miles