A GPS-based Evaluation of Factors Commonly Used to Adjust Cattle Stocking Rates on Both Extensive and Mountainous Rangelands

Abstract

On the Ground • Published research provides guidelines to reduce stocking rates on areas >10% slope and >1.6 km from water because these areas may be considered ungrazeable. • Data from 180 cattle tracked by GPS collars for 1 to 4 months at seven ranches in New Mexico, Arizona, and Montana on average resulted in grazeable area calculations that were approximately 10% higher than those derived from published guidelines. • In several cases, published guidelines yielded more conservative stocking rate estimates compared with our GPS-based calculations. However, our data should be interpreted with caution because most data were collected over a single season or year. • Our results support recommending local experience and information be used in applying published guidelines to adjust stocking rates. These guidelines may not reflect site-specific management and the adaptability of cattle to local conditions. • Animal GPS tracking is a sound tool to monitor spatial impact of grazing on rangelands and could be used to enhance commonly used stocking rate adjustment tools, such as annual monitoring of precipitation, forage production, and grazing intensity on key areas.