Ultrasound Pregnancy Testing – A few things you should know

Pregnancy testing beef cows has progressed from predominantly rectal palpation 20 years ago to mainly ultrasound pregnancy testing today. About 30 years ago Dr. Andrew Bronson, a Canadian veterinarian, and his partner, Bruce Hill, started doing ultrasound checking.

Bronson came to Alberta, Canada after graduating from veterinary school in 1982 and went in to beef practice. “Most ranchers have their cows pregnancy- checked in the fall, and it’s a very short season for this so it kept us very busy each fall,” says Bronson. By the time he was 45, 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, and after using it several years, saw the benefits. Due to mechanical problems with that model, however, Bronson and his partner developed their own extension-arm ultrasound, called ReproScan.

The ReproScan had a linear probe at first, then he heard about a convex probe. “This produces a pie-shaped image, and can be as large as the size of your han—versus a credit-card size picture with the linear probe,” he says.

At first the main use for this equipment was in dairies because they check for pregnancy as early as possible. “When we started our business there was no beef unit available with the convex probe. We created one and put it into a portable case. We thought the biggest market, initially, would be for feedlot heifers. My partner and I were involved with live cattle export when the border closed because of BSE and then
reopened and all heifers had to be preg-checked. Nothing pregnant was allowed to be exported, so we did 150,000 heifers by ultrasound in 2 ½ years. We wouldn’t have been able to do this without extension-arm ultrasound,” he explains.

Bronson says that ultrasound pregnancy testing can be split into two categories, the “arm in cow” technique which is generally done with a linear probe and the extension arm ultrasound technique. An example of linear probe “arm in cow” would be for very early pregnancy testing of synchronized heifers. The goal would be to determine the pregnancy status of the heifers at 30 days post breeding and to examine the reproductive tracts of the open heifer and re-synchronize them. A procedure like this takes considerable training and skill. Fetal gender determination is another procedure that is usually done with “arm in cow” linear probe technology.

For routine pregnancy checks, extension arm pregnancy testing has replaced rectal palpation for most veterinarians. This technique was introduced to North American veterinarians 16 years ago by ReproScan. The equipment used is a convex rectal probe that is held in a plastic extension arm. This equipment provides a larger field of view compared to a linear rectal probe and thus has several advantages.

Extension arm ultrasound is easier to learn, easier on the body and quicker. Fetal aging and detection of twins can be done but this requires experience and proper timing of pregnancy testing. If cows are pregnancy tested 40 to 120 day post breeding, fetal aging is considerably more accurate. Once the cows are over 4 months in gestation, the fetus has often dropped into the lower abdomen and accurate feta l aging and detection of twins can be much more difficult.

The ReproScan Technologies ultrasound company focuses on providing excellent service, and a big part of that service includes training. Dr. Bronson has recently retired from training, but several veterinarians and Elle Terhaar continue to teach RACE approved bovine ultrasound courses of behalf of ReproScan. Elle Terhaar, the CEO of ReproScan is also a RACE- certified ultrasound trainer. RACE (Registry for Approved Continuing Education) is one of the programs of the American Association of Veterinary State Boards. Elle is one of the few non-veterinarians in the U.S. who is qualified to provide continuing education courses on ultrasound training for veterinarians and is accredited to teach ultrasound courses.

There is currently a big demand for training—not only for veterinarians but also for non-veterinarians: vet techs, feed-yard staff and ranchers themselves. It’s also important to educate people about how best to “setup for success” in their ultrasound pregnancy testing whether they own their own machine or work with their local veterinarian. It is important for people to know their skill level and how to set up the equipment for the required type of pregnancy testing.

Make sure you pregnancy test at the stage of gestation that will allow you to gather the information you need to make the correct management decisions, especially if you want to determine how far along the pregnancy might be. For example, with fetal aging information, you can identify later-calving older cows which might be better marketed as bred cows or cull cows rather than stay in your herd.

The Repro-Scan website has many training resources; there are on-line courses, and in-person training courses. Some are for veterinarians and some are for non-veterinarians, and teach different levels. Up-coming ReproScan training courses are usually posted on the website by June 15th. The on-line training courses are very good, for the people who are interested, and YouTube instruction is also helpful.

It is important to make sure you get the right equipment for what you are trying to do. Talk to the ultrasound companies. Make sure the person selling you the ultrasound equipment asks you what your goals are and how you wish to achieve these goals. About 90% of the people wanting to ultrasound are a good fit for the convex probe because they will want to use the extension arm and do a reasonably good job at fetal aging. Other people may want a linear probe for very specific uses.

One word of advice from the ReproScan team: Make sure you don’t get talked into a linear probe when what you really need is a convex rectal probe and an extension arm. This happens occasionally when people don’t understand the difference and are stuck with an ultrasound unit that does not meet their needs. Most people who don’t have much experience yet with ultrasound will really struggle with a linear probe when a convex rectal probe will be much easier to learn to use.

Another decision point is to determine which viewing device fits your needs the best. ReproScan personnel encourage clients to consider using a monitor that can be mounted strategically at the chute in a position you can utilize it efficiently and comfortably. A proper monitors has several advantages including good image quality and safety. Some chute setups require googles, also known as head mount displays. The ultrasound company that you are working with should let you try both options so you can make the right decision.

A topic that often comes up regarding pregnancy testing beef cows is the question regarding who is legally allowed to charge for pregnancy testing. Most state and provincial laws state that pregnancy testing is an act of veterinary medicine and only veterinarians are allowed to charge for pregnancy testing services. Ranchers, feed-yard managers and their full-time staff are allowed to ultrasound pregnancy test cattle under a veterinarian’s direct management. There are a few states where beef cattle pregnancy testing is de-regulated. Check your state regulations to make sure you understand the rules in your jurisdiction.

Pregnancy testing feeder and replacement heifers going to pasture is another use for extension arm ultrasound. More and more feed-yards and pasture operations are ultrasounding all their heifers on arrival. Cattle are worth a lot of money today and knowing the pregnancy status of the heifers is very important and can save or make you money. A recent example that demonstrated the value of pregnancy testing heifers occurred when a producer purchased a group open heifers that were supposed to be guaranteed open and were preg-checked upon arrival.

At that point the producer discovered that one of them was going to calve fairly soon. If the producer hadn’t known about the pregnancy, all of those heifers would have been turned out on grass, and that calf would have been lost and possibly the heifer as well, because the calf had to be pulled. But knowing the heifer was in later-term pregnancy, she was put into a pen next to the house, where she could be watched. They were able to save the calf and the heifer, which saved quite a bit of money.

There are other ways to use ultrasound to add value to pregnant cattle when cattle prices are high. For example, you might be able to put together a group of late-bred cows that somebody else might want; a group of bred cows can be worth a lot more than cull cows that are not pregnancy tested.

This is just one of many ways that ultrasound checking can add value to cattle. Ultrasound can be used successfully for splitting A.I. bred heifers from bull bred heifers. Bred heifers can be sorted into calving groups by stage of pregnancy. Twins can be detected and those heifers (or cows) and be tagged differently so they can be watched more closely at calving time. Saving a set of twins can make a big difference.

These little things can save/make a person a lot of money each year. If you don’t know when a cow or heifer is going to calve and she’s not where you can watch her and she has a serious problem, you might also lose the cow or heifer. That can be a huge loss. This technology won’t eliminate all calving issues, but it gives you more information.

Some producers sort their pregnant cows/heifers into separate calving groups, depending on when they are expected to calve—and thus don’t need to have all of them under close watch from the beginning. If a person uses synchronized AI, that group can be closer to the house and barn because they will start calving first. The first-cycle bull bred females can be in another pasture and the second-cycle bull breds in a third pasture.

This system is not perfect, because when a storm comes through, a lot of them will calve earlier than their due-dates, but it still helps to know which ones are closer up and which ones will calve later. This just makes it easier to manage them, especially on the heifers.

If you utilize a veterinarian who is very good at doing the ultrasound and you can schedule the preg-checking during the right time window, you will be able to know which group those females should be in. You could also cull any animals that bred late. For your replacements you could select the heifers that bred right away and will calve early—giving them more chance to rebreed on time and stay in the herd.

Some people like to preg check when their AI group is at the right stage to facilitate fetal sexing. Maybe you might want to keep only 30 heifers and you have 50 that are bred. If your goal is to keep more replacement heifers you might keep more of the females carrying heifer calves. If you are raising bulls to sell, or just want more steer calves to sell, you might keep all females that bred AI and if there are two that are exactly the same but one is carrying a bull calf, that would be a more productive animal. This can help you make one more management decision that could make a little more money.

Unless you have a veterinarian doing this however, you might not opt to try to determine the sex of the calf, however, because fetal sexing takes a long time to learn, but it is a great tool to use. Even more useful for most people is that with ultrasound you can see the females that lost the calf for some reason and is still retaining the dead fetus. If a person is palpating, it is almost impossible to tell if it’s a live fetus or dead, but on ultrasound it looks very different. If that cow or heifer has lost the calf, you don’t want to keep feeding her. Since cull cow prices are high right now, it’s best to sell her.

Elle Terhaar will be speaking to the Montana Veterinary Association’s Summer Conference in June. Her topic will be how to set up for success, value added pregnancy testing and how veterinarians can improve their preg-checking skills. The discussion will include how veterinarians can continue to offer advanced services when ranchers are getting good at doing ultrasound pregnancy testing on their own.

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