Crossbreeding is one of the most underexploited breeding tools in the beef industry. The industry’s recent push for larger carcass weights while keeping cow costs at a minimum has brought terminal crossbreeding programs to the forefront. Dr. Mark Thallman, a research geneticist from the USDA Meat Animal Research Center in Clay Center, Nebraska, laid out a vision for terminal crossbreeding that allows producers to get the best of both worlds during the Advancements in Producer Education breakout session. The session part of the 2024 Beef Improvement Federation (BIF) Symposium in Knoxville, Tennessee.

Thallman’s main message was that if the growth potential of a herd’s cows and bulls are the same, that profit potential is likely being left on the table. This is due to the antagonism between cow resource needs (costs) and terminal output (revenue).

“Terminal crossbreeding programs mean breeding cows that are strong in terminal traits to bulls that are strong in terminal traits,” said Thallman, “We did this extensively in the 1970s, but the biggest challenges were producing a sufficient number of replacement females and issues with calving difficulty.”

To address this deficit of replacement females in terminal crossbreeding programs, Thallman proposed several solutions that might fit production systems across the U.S., from one-bull herds to large commercial operations. In herds where having an entirely separate maternal herd is impractical, an optimal approach would be to purchase young cows, pregnant with their second calf, allowing for using a purely terminal bull without concern for introducing calving difficulties. This system would require herds focused on breeding these maternal replacements, likely leveraging sex-skewed semen.

Thallman underlined that genetic selection in these schemes should be driven through bull selection.

“Culling should be minimal and based almost solely on the immediate effect on profitability,” he emphasized, “We shouldn’t cull commercial cows with the hopes of improving genetics.”

This is a function of the low heritability of these traits and the limited selection intensity that can be achieved on females in commercial herds. To this end, he drew attention to the need for continued development of EPDs for maternal traits.

While much of Thallman’s talk drew on the conventional wisdom of crossbreeding that we have known for decades, his call for a more targeted creation of divergent maternal and terminal populations would require some changes across the industry. In particular, breeds would need to adopt more targeted breeding objectives focused on terminal or maternal suites of traits. The most important of these would be mature size, as maternally oriented breeds should be much more moderately sized than high-growth terminal breeds.

Finally, this vision for industry-wide terminal crossbreeding would require a somewhat new segment of the industry to develop aimed exclusively at producing replacement females. These ideas would encourage breed complementarity, maximize heterosis and help make the entire beef production chain more efficient.

For more information and to watch Thallman’s presentation visit beefimprovement.org.