There will be few surprises for Ole and Shirley Redland this calving season, thanks to utilizing ultrasound technology to pregnancy check their cowherd last summer.

For the past four years, the Hysham, MT, couple has been using ultrasound as a crystal ball to look into their future calf crop. But these Red Angus breeders have found that ultrasound offers benefits beyond the simple yes/no answer of whether a cow is carrying a calf.

With the help of veterinarian and ultrasound technician Ralph Miller from Livingston, MT, the Redlands are also using ultrasound to determine fetal age and sex of calves. And that has helped them add efficiency and profitability to their cow herd.

"We sell commercial and registered females and have used ultrasound as part of our program to sell those cattle," says Ole.

By preg-checking with ultrasound, the Redlands are able to offer their customers the cow's expected calving date, sire information and the sex of her calf.

For example, by identifying females that are having heifer calves and females that will have bull calves, their customers have options to select what fits their operation. "This works well for those buyers wanting replacement females," says Ole.

How Ultrasound Works Ultrasound pregnancy detection is accomplished by inserting a transducer into the cow's rectum and directing sound waves toward the uterus. An image of the fetus then appears on a small screen.

Fetal sex determinations can be made between days 60 and 90 of gestation by locating the position of the genital tubercle, which will form the penis in males and the clitoris in females.

Fetal age is more difficult to determine, according to Miller. It is predicted by measuring body length between days 28 and 49 of gestation (see Figure 1) or dome width of the skull from days 50 to 90 of gestation.

Miller has been involved with ultrasound for over 12 years, and says the technique isn't something that's learned in a day. It takes finesse. The key is measuring the head in the correct place.

He worked with veterinarian Meg Cattel at Colorado State University to devise a chart correlating dome width of the head to days of age. Using artificially inseminated dairy cattle, Miller and Cattel compared dome width to fetal age on hundreds of cows until they felt their chart could accurately predict fetal age. (See Figure 2.)

Last summer, Miller used ultrasound to preg-check nearly 45,000 heifers and cows across the Dakotas, Montana, Wyoming and Idaho. He predicts within two days of actual breeding date 85% of the time. The other 15% are within four days of actual breeding date.

More Management Options Being able to pinpoint breeding dates that exact has been valuable for Miller's customers, who are about half commercial producers and half purebred producers.

"I do a lot of ultrasound for people who've been hurt in spring storms," says Miller. Knowing the breeding date, allows producers to group cows by calving interval. Then, they only have to watch those in a particular calving interval in the event of a storm, he adds.

Identifying later calving females, or open females, also allows producers flexibility in their management decisions, Miller points out. For example, he sells the late calvers in his own herd. When he knows they're open, he tries to sell them early when the market is up.

The Redlands also have used the ultrasound information to cull late calvers and shorten the calving season. "When you knowhow long your calving season will be, you can better spend your time on other things," says Ole.

Miller says producers that AI are also apt to use ultrasound to preg-check. Knowing the time frame of when a cow was bred can help producers determine if the cow was bred AI or by a clean-up bull, says Miller.

Redland says his customers like having insight into which sire lines the females they purchase are bred to.

Another benefit of ultrasound is determining if it's a nonviable pregnancy (i.e., deteriorated membranes, no movement or heartbeat). "Were you to manually palpate you couldn't diagnose a non-viable pregnancy. You can diagnose those things with ultrasound," says Miller.

Ole admits ultrasound preg-checking is an extra step that requires handling the cattle in a hydraulic chute, record keeping and expense. Ultrasound pregnancy checking can cost $3-5/head. "But the rewards are worth it," he says.

"There's no question from the way it's growing that it's a technology that can do the industry some good," Miller says.

But he cautions that ultrasound technicians have to have integrity. "Emphasis must be placed on accuracy," Miller says.

To keep his predictions calibrated, Miller still gets the actual AI breeding date back from his customers after testing and compares it to his predictions.

After 90-95 days, the fetus's head is larger and it's difficult to predict age accurately, he says. Therefore, he recommends ultrasound pregnancy checks shouldn't be done after 90-95 days gestation.

"If you're off a few days, producers won't be watching the right animals when the big storms hit," he adds.