Last fall, I wrote a post talking about how veterinarians use rectal palpation to determine if a cow is pregnant. This year, I wanted to tell you all about another method to determine pregnancy status: ultrasound. Yes, this is the same ultrasound technology used in humans to look at the pre-born baby. Unlike a people ultrasound, this machine is portable and has a screen with wearable glasses.
Ultrasound has a few advantages over rectal palpation. With ultrasound, you can determine if the cow is bred over two weeks sooner, which is as early as 28 days gestation. Ultrasound is also more accurate at determining the age of the fetus than palpation if done in the first 100 days of gestation. With ultrasound, a veterinarian can determine the gender of the calf.
The disadvantage of ultrasound is the expense. The machine itself costs over $13000 for a new unit. What is the most concerning about that is the probe, which is $7000, has to be put in a precarious place.
Because cattle skin is so thick, the ultrasound machine cannot penetrate through it well. So the probe must be inserted rectally, just like we do when palpating. This makes it a bit scary when the cow jumps; she might beat up the probe and you’re out a big chunk of change. So we don’t use it for all cattle, only the ones that we need to age the babies more accurately or need to see if they are bred earlier.
The images we see are not quite as clear as the new human machines, but they do the trick. It’s pretty cool to see the calf’s heart beat that early in life too (at less than two months even!). So ultrasound is a great tool to use in certain applications, but doesn’t take over for palpation in all situations.