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Ultrasound technology allows easier preg checkin, increased accuracy in results

by Wyoming Livestock Roundup

Pregnancy testing is generally done by rectal palpation, but many veterinarians also use ultrasound. Most commonly used is arm-in trans-rectal ultrasound, putting their arm into the rectum.
    Today there’s an easier method.
Developing new tools
    Andrew Bronson graduated from veterinary school in 1982.
    “Most ranchers have their cows pregnancy-checked in the fall. I was proud of my palpating skills, because this is what makes or breaks you as a beef cattle veterinarian,” says Bronson.
    By age 45, however, the wear and tear on his arm and shoulder – multiple strain injuries after palpating cows all day – was taking a toll. He bought an aluminum extension-arm ultrasound unit, made by a company in another country.
    After using it several years, he saw the benefits. Due to mechanical problems, however, as well as the long distance and turnaround time on repairs, Bronson and a partner, Bruce Hill, developed their own extension-arm ultrasound, called ReproScan.
Benefits of technology
    This type of ultrasound equipment is easier to learn to use than palpating, as well as being easier on the body. Also, there are certain stages of gestation in which ultrasound is much more accurate in determining the age of the fetus.
    “As the cow gets farther along in pregnancy, ultrasound is not quite as accurate as palpation for someone who’s done hundreds of thousands of palpations. But ultrasound is probably more accurate for the inexperienced person because it’s easier,” says Bronson.    
    Veterinarians who spend a lot of time palpating or doing arm-in ultrasound wear out – it’s rough on them. The average height of veterinarians is dropping because there are more female veterinarians now, and this makes it even more difficult for them to palpate cows all day.
    “Today the pressure is on veterinarians to go through a lot of cows quickly. Fewer veterinarians are interested in taking the time to learn to palpate,” he says.
    Ultrasound can do a good job of aging the fetus.
“Under 120 days, ultrasound in general can be quite accurate – more accurate than anybody palpating cows, and there are some really good palpaters,” he says.
Margins for error
    All forms of pregnancy checking, whether using palpation or ultrasound, become less accurate on fetal aging in advanced pregnancy. It becomes more difficult after 120 days’ gestation because the uterus drops below the rim of the pelvis and there are also variations in the size of the fetus and cotyledons.
    “Other things start affecting the size of the fetus, as well, including genetics and nutrition,” explains Bronson.
    There are many stories about sale-barn preg-checking errors.
    “Even vets who have done hundreds of thousands of cows err now and the. Sometimes the auction yard has to put those cows into two-month windows or even one month. If a cow comes in at what the vet thinks is a six month pregnancy and it’s an eight month fetus, she calves earlier than expected and the calf freezes to the ground, the buyer is angry. But it’s easy to make that mistake, especially on a big old cow where you can’t reach the uterus.”
    “If you put our extension arm in there, however, and see large cotyledons and maybe a hoof, you can say it’s at least six months. When palpating, if you are good at this, you can get a feel for the weight of the uterus, size of uterine arteries, etc. and all these things can give you information. Once you have done 100,000 or so, you can quickly say you think she’s more than six months – maybe seven or eight,” he says.
    “But this is hard on your body and you are still going to be off, now and then, by one or two months. This can be misleading to the person trying to put together a package of April calvers,” Bronson says.
    Most of the old vets who were really good at palpating are gone or retiring.
    “Palpation is a difficult skill to learn and it’s hard for young veterinarians to gain experience quickly enough. It’s easier to learn to do ultrasound,” he explains.
Ultrasound options
    The ReproScan equipment costs about $10,000, which is feasible for a veterinary practice, a big feedlot, or large cattle operation.
    “We now have a portable unit. There are two groups of vets who like our technology – the older vets who want things easier on their bodies, and the young vets who like the new technology,” he says. His company provides demo equipment and training courses – for veterinarians and producers.
    There are various types of ultrasound equipment and they all do a certain job.
    “In the beef industry we need to be accurate and save our arms. We’ve had veterinarians buy these units because their body is worn out, and they want to stay in practice a little longer and enjoy life,” he says.
    “When I got this equipment it was to save my body. It does the same job I was able to do with my hand. I don’t charge clients more for this service. But if they ask me to do accurate fetal aging, which takes more time with ultrasound, then I charge more. If they just want pregnant yes/no with a set of ranch cows – the same as I did by palpation – I don’t charge more for the ultrasound,” he explains.
    A rancher with a lot of cows might buy one for his/her own use. If there are 1000 cows on the ranch, and this equipment lasts 10 years or more, the cost would be about one dollar per head or less.
    For more information about ReproScan, visit Heather Smith Thomas is a correspondent for the Wyoming Livestock Roundup. Send comments on this article to

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