With cattle prices falling, it could pay to preg check your cows this fall — but which method should you choose?
“The method that best suits your situation will really depend on the management of your herd, your geographic location, potentially even the year,” said Dr. Jessica Gordon, an assistant professor at the Ontario Veterinary College.
Rectal palpation — which involves a veterinarian inserting a gloved hand into a cow’s rectum to feel for the fetus — is the most commonly used method in Western Canada. But blood tests and rectal ultrasounds using a hands-free probe are becoming more common, Gordon said during a Beef Cattle Research Council webinar.
Each method comes with some pros and cons, she said.
Rectal palpation, for instance, costs about $5 a head and doesn’t require special equipment — “anyone can buy plastic sleeves and lube from your local farm store.”
“But the skill required takes a lot of time and practice to really be efficient and effective at it. It takes palpating thousands of animals before the accuracy is quite good,” said Gordon, adding experienced practitioners can have an accuracy rate of 99 per cent.
Rectal ultrasounds work a little like human ultrasounds, by taking an image of the fetus, she said.
“At 35 days, it may not look like much that’s easily identifiable as a calf, but we can get a picture of the heart, and we can actually see those valves moving,” said Gordon. “We can make sure the heart rate is good and that the heart seems to be functioning properly. That helps us determine the viability of that fetus.”
But it’s often the costliest option for preg checking, at between $5 to $10 a head.
“Some practitioners think this saves so much wear and tear on their arm that they’re willing to offer it at the same fee as rectal palpation,” she said, adding it’s also quicker.
But practitioners require an ultrasound unit (which is “fairly expensive”) and the skill to accurately read the ultrasound screen.
“It does require a fair bit of practice to be able to master this skill, but it can be upwards of 99 per cent accurate,” said Gordon. “Because you’re able to look for that fetal heartbeat and you can see exactly what’s in the uterus, you get a little bit more accuracy than you can with rectal palpation.”
Blood tests are a relatively new tool for preg checking, and as such, some on the market have “questionable” accuracy, said Gordon, adding a test called BioPRYN is the “most promising” one currently available.
“The cost is about $5 per head, but again, that’s going to vary greatly based on where you are because it requires shipment to the lab,” said Gordon, adding producers can buy kits that include everything they need to do the test.
Unlike the other methods of preg checking, blood tests don’t require a veterinarian, making it the most cost-effective option for a small herd or for farms not located near a veterinary practice. But results from blood tests may take up to a week and may give a false positive, she added.
“The accuracy of this test is about 99 per cent for open cows and 93 per cent for pregnant cows, which means if the test says the cow is open, it’s going to be right 99 per cent of the time,” she said. “If the test says the cow is pregnant, it’s going to be right 93 per cent of the time, which means seven per cent of the time, it’s going to be wrong.”
Producers will need to choose the best method for their herd based on their own operation.
“The type of pregnancy checking you choose to use might vary from year to year or group to group on your farm,” she said. “You have to discuss with your veterinarian to really help you choose what’s the most appropriate for your situation — what’s going to give you the best bang for your buck.”