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UW hosts annual Ram Test Field Day

by Wyoming Livestock Roundup

The University of Wyoming (UW) Research and Extension Center hosted its annual Ram Test and Field Day on April 13 at the Laramie Research and Extension Center (LREC).

The event celebrated its 65th anniversary, and UW presented results from the 140-day performance test, as well as how test results can be used to assist producers in making selection decisions. 

Along with highlighting data and historic trends, the Wyoming Wool Initiative provided lunch, and attendees had the opportunity to view tested rams and participate in a silent auction.

UW test highlights

“This was the first year we hosted international rams at the event,” stated UW LREC Assistant Farm and Sheep Unit Manager Kalli Koepke. “We received 89 head of rams from 21 producers across Texas, Wyoming, South Dakota, Utah, Colorado and Canada.”

She noted the event showcased three Rambouillets, two Columbias, two Natural Rambouillets, five Targhees and two Merino and Merino-Rambouillet crosses.

With this centralized test, UW produces specific data on a variety of traits, giving producers the opportunity to use genetic testing to improve their herds.

Ram performance was evaluated based on growth performance, feed conversion efficiency and muscling, as well as wool traits including weight, fineness, length and clean yield. 

Rams who perform in the top 30 percent of the test were eligible for the Certified Rambouillet Index and Wyoming Certified Index.

“We have conducted this central performance test since 1961, and improvement in ram quality over this time has been remarkable. This was an amazing year,” said Whit Stewart, UW Extension sheep specialist. “There are only two of these central performance ram tests left in the nation, and we are proud ours has endured.”

The test also provides learning opportunities for students in UW’s Sheep Program, while gaining hands-on experience in production agriculture. Students help gather performance data throughout the test and conduct genomic research.

“Aside from the decision-making tool the test provides to producers, it is an important partnership with the Wyoming Wool Growers Association and individual producers in our region,” Stewart stated.

A successful year

“We complete two indexes every year for the test – the Wyoming Certified Index and the American Rambouillet Sheep Association’s register of merit (ROM) which follows traits specific to the Rambouillet breed,” Koepke explained.  

Only registered Rambouillets are allowed to participate in this index, and UW had 13 head of registered Rambouillets certified on this index in this yearʼs tests.  

The Wyoming Certified Index was developed by Stewart to include all rams on test, no matter the breed.  

“This index follows more of what the industry is looking for in sires to have optimal lamb growth,” Koepke said. “Where the ROM index is weighted heavy on wool growth and performance, the Wyoming index is weighted more on overall growth of the animal, such as average daily gain, feed efficiency and carcass traits.”

There were 13 head of rams certified on the Wyoming index, including the top performing ram, raised by Jeff Jacobs of Happy Valley Farms, LTD of Alberta, Canada. 

“It was a good year for the test. We had minimal sickness, and rams grew exceptionally well,” Koepke noted. “The mild weather this winter also helped a lot as well.”  

Koepke further noted the 2024 field day was also a success, with nearly 30 producers in attendance, some of which consigned rams and some who were potential buyers. 

“We’re proud of the long-standing tradition of the Wyoming Ram Test, the selection tool and our partnership with producers,” said Stewart. “Each year we try to add innovative ways for producers to utilize the information it generates, while also incorporating it into our teaching curriculum here on campus.”

For example, Stewart mentioned unique to this year’s test was a structural scoring system which looked at hocks, front feet and pastern angle. UW students in Stewart’s advanced sheep production class helped gather this information. 

“It is a tremendous effort to feed close to 100 head of rams for half of the year, combined with our Lamb-A-Year program, but it is a source of pride the UW Ag Experiment Station and LREC are still all in on the sheep industry,” he concluded. “Good programs are a true result of true partnerships and collaborations, and the ram test and our UW Sheep Program are an example of this.” 

Melissa Anderson is the editor of the Wyoming Livestock Roundup. Send comments on this article to

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