TOOLS FOR BREEDING CATTLE THAT TRULY FIT THEIR ENVIRONMENT
Insights from Troy Rowan, PhD, University of Tennessee, during his Cattlemen’ s College session at CattleCon 2026.
In beef production, genetics often take center stage, but genetics alone don’ t tell the whole story. At CattleCon 2026, Troy Rowan, PhD, assistant professor of beef cattle genomics at the University of Tennessee, emphasized a simple yet powerful truth: not all cattle are built for all environments. And if we expect cattle to reach their full genetic potential, we must match the right cattle to the right conditions.
Rowan opened his presentation with the concept of Genetics-by-Environment indications or GxE. This principle recognizes that an animal’ s genetic potential doesn’ t express uniformly across different climates, landscapes or management systems. In other words, a cow that thrives in the humidity of Florida might perform differently if transported to the harsh winters of Montana. The animal is genetically identical in both scenarios, but the environment changes how those genetics are expressed and how the animal will perform.
For decades, regional adaptation happened naturally. Producers bought bulls from local ranches and seedstock suppliers because those animals were proven to succeed in the local conditions( i. e. available forage, rainfall patterns, temperatures, parasites and disease pressures). But today, with the widespread adoption of artificial insemination, genetics can be shipped across the country and across continents. While this offers enormous opportunities, it also introduces a major challenge: the loss of region-specific adaptation in the U. S. cattle herd.
Importantly, Rowan challenged the assumption that“ environment” can be defined by a ZIP code. Two neighboring ranches separated solely by a fence can be diverse in forage species, soil types, water access and grazing pressures.
“ We need to use tools to make sure we’ re putting genetics, whether from AI or traditional breeding, into the right environmental context,” Rowan said.“ Without that context, producers risk losing an opportunity to match cattle to their climate and management system.” Three Paths Forward Rowan outlined three strategies available and emerging for pairing genetic selection to conditions: 1. Buy local bulls and proceed with the traditional method. While locally adapted genetics can be beneficial, Rowan cautioned that relying only on traditional methods is no longer the best option because it limits access to the immense pool of genetic potential available today.
2. Add adaptive indicator traits to selection objectives. This means deliberately selecting for traits that reflect how well an animal can handle environmental stressors. Some examples include early-season hair shedding for heat stressed environments and pulmonary arterial pressure for animals living at higher elevations.
3. Develop new EPD models that account for GxE. This is the emerging frontier that Rowan and his collaborators are researching and, arguably, the approach with the greatest long-term potential. This could entail updating current genetic models or using existing EPDs within a predictive model customized to a producer’ s environment and management.
Dr. Troy Rowan presented research to a packed room during Cattlemen’ s College at CattleCon 2026.
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