Economic feasibility of grazing sheep on leafy spurge-infested rangeland in Montana

Abstract

Leafy spurge (Euphorbia esula L.) is a noxious weed on rangelands throughout the Northern Great Plains. Most of these ranges are grazed by cattle which do not use leafy spurge as forage. Although sheep graze leafy spurge, most land managers are reluctant to use sheep to control this noxious weed, which may be related to economic uncertainties regarding their profitability. The purpose of this study was to evaluate the economic feasibility of implementing a sheep enterprise to control leafy spurge on cattle ranches. The physical characteristics of a typical Northern Great Plains ranch, recommended stocking rates for cattle and sheep on native and leafy spurge-infested rangelands, and a sheep enterprise budget were developed using information from the literature. A LOTUS® spreadsheet was developed to calculate returns over total costs of implementing various sheep enterprises. Annual returns from implementing sheep grazing on 520 ha of leafy spurge on a 4,905 ha ranch exceeded total costs by 4,675. Given the ownership costs and returns of our ranch, the breakeven lamb price would be 1.16 kg-1. Returns per head and per unit of land will vary with the distribution and size of a leafy spurge infestation, and sheep production costs and returns. Returns from sheep grazing were higher when leafy spurge was concentrated in fewer rather than in many pastures. Returns were positive when as little as 4% of the ranch was infested with leafy spurge. The availability and utility of our model will allow land managers to assess the feasibility of developing sheep enterprises to control leafy spurge.