Defining production environments in U.S. sheep populations: clustering climate conditions and management practices

Authors: YAZAR GUNES, HILAL - University Of Nebraska; HOWARD, REKA - University Of Nebraska; Murphy Jr, Thomas; Wilson, Carrie; Freking, Bradley; Burke, Joan; Taylor, Joshua; BRITO, LUIZ - Purdue University; LEWIS, RONALD - University Of Nebraska

Submitted to: Journal of Animal Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/31/2026
Publication Date: N/A
Citation: N/A

Interpretive Summary: Sheep producers across the United States manage animals in a wide range of environmental conditions, including different climates with varying forage availabilities and parasite challenges. Traditionally, production environments are defined based on geographic regions. However, that approach overlooks the distinct strategies producers use to accommodate their local conditions. In this study, we used a holistic method combining climate data with producer reported management practices to define “eco-management clusters”, groups of flocks experiencing similar environmental pressures and adopt similar management styles. Using responses from a survey of sheep producers enrolled in the National Sheep Improvement Program (NSIP), we characterized differences in flock sizes, lambing systems, and feeding and parasite control strategies. Climatic conditions were defined based on a flock’s location. Although climate data alone explained much of the variation in environments, management data helped delineate differences in practices used in flocks located in the same ecoregion. For example, Katahdin producers employed various parasite control strategies while Polypay producers implemented a mix of lambing and feeding systems even within similar climates. By defining production environments based on eco-management clusters, management and selection strategies can be tailored to match animal genetics with the conditions producers face, ultimately improving animal performance and climatic resilience.

Technical Abstract: Sheep production in the U.S. spans diverse geographies and management practices, which are traditionally classified by climate alone. By combining information on climatic conditions and their management practices, we assigned groups of flocks to distinct eco-management clusters that characterized their shared production environments. Producers representing 97 flocks and five breeds enrolled in the National Sheep Improvement Program (NSIP) and completed an online management survey. Breeds included Katahdin (n = 50), Polypay (n = 21), Suffolk (n = 13), Rambouillet (n = 8), and Targhee (n = 5). The questionnaire considered parasite control, lambing and udder health management, culling strategies, feeding methods, and climate mitigation practices. We characterized the climates at producer locations based on elevation, seasonal precipitation, soil moisture, and the Comprehensive Climate Index (CCI). The CCI integrated ambient temperature, humidity, wind speed, and solar radiation to reflect thermal stress. Clusters were first formed based on climate or management data via Principal Component Analysis and Multiple Correspondence Analysis, respectively. Both sources of information were then combined to form eco-management clusters using Factorial Analysis of Mixed Data. Cluster quality (cohesion) was assessed using silhouette widths. Differences among clustering approaches were tested with chi-square cross-tabulations and permutation tests. Flock assignments to climate and to management clusters were, statistically, independent within breeds (P > 0.16). Flock assignments to eco-management and management clusters, however, typically aligned (P