Sheep GEMS News Brief 13 – April 2025
Sheep producers across the U.S. operate in a wide range of environments—from humid grasslands to dry, high-elevation rangelands. These environmental differences, along with varied management practices, mean that a “one-size-fits-all” approach to genetic selection often falls short. In other words, the animals that perform best across all environments may not be the same, which could have implications when selecting breeding animals. To help address this challenge, our team in the Sheep GEMS project has developed a tool — coined eco-management clusters —designed to help producers select animals that are best suited to their specific production conditions. These eco-management clusters were developed using survey responses collected separately for each breed, capturing detailed information about flock management practices and geographic location. Flocks were then grouped into eco-management clusters based on similarities in both climate (such as temperature, precipitation, and humidity) and management practices (such as at-grass compared to confinement lambing systems). The goal is to account for the real-world differences in how we raise sheep so that we can better understand how those factors interact with genetics.
We have identified several distinct environmental clusters within our major U.S. sheep breeds, including Katahdin, Polypay, Rambouillet, Suffolk, and Targhee. For example, one cluster included flocks raised in hot, arid regions with limited forage availability. In that cluster management tended to be more extensive with less intensive feeding and outdoor lambing. Another cluster included flocks in similar climates but with more intensive management, such as supplemental feeding and barn lambing. Likewise, in cooler, wetter regions we observed that flocks differed in their feeding strategies and lambing practices. Our findings highlighted how climate and management decisions combine to define distinct production environments, and thereby distinct eco-management clusters.
By recognizing these clusters, we can start to answer questions like: Do certain rams sire lambs that perform better in some environments than others? And can we improve selection tools to reflect these differences?
This research matters because selecting animals based on existing national-level breeding values may not fully reflect how those animals will perform in your production environment. By incorporating eco-management clusters into genetic evaluations, we can give producers more tailored tools to identify animals that will thrive in their own unique systems.
With our framework of eco-management clusters, we aim to improve the accuracy and usefulness of genetic evaluations. Our goal is to make genetic selection more relevant to the day-to-day realities of sheep production, and empowering producers with information that fits their operation.
Our long-term goal is to ensure U.S. sheep genetic evaluations keep pace with environmental and management challenges—helping producers build more sustainable flocks that stay healthy, productive, and profitable for years to come.
For further information contact Hilal Yazar Gunes (hyazargunes2@huskers.unl.edu).
Acknowledgements. We thank producers participating in the National Sheep Improvement Program for completing an on-line survey of their management practices. This work was supported by the Organic Agriculture Research and Extension Initiative (grant 2016-51300-25723/project accession no. 1010329), and by the Agriculture and Food Research Initiative Competitive Grant (grant 2022-67015-36073/project accession no. 1027785), from the USDA National Institute of Food and Agriculture. The USDA is an equal opportunity provider and employer. Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily
