Rangelands – In Wyoming, about $4 million worth of rangeland cattle and sheep were lost to predators in 2005. Using a computerized model, researchers have now simulated an individual ranch’s economic impact of livestock losses to predators such as wolves and coyotes. Both short-term profitability and long-term viability were found to be affected by predation.
The article appears in the June 2010 issue of the journal Rangelands. The Western Wyoming Grazing Model simulates cow–calf operations, taking into account herd size, grazing strategies, annual livestock sales, and fluctuating cattle prices to determine ranch income and viability.
The model uses three scenarios to predict the consequence of predation on profits: decreased weaning weight, increased death loss, and increased variable costs. Of these, reduced weaning weight had the greatest impact. This is because all calves would become less profitable when the stress of predation resulted in a lower sale weight, whereas death loss would affect only those animals directly lost to predators. Reduced sale weights of up to 5% were sustainable in this model. However, we have little scientific data describing the impact of predation on weaning weights and a better understanding of this relationship is needed.
With an annual death loss of 4%, a ranch would experience negative profits in 3 of 10 years. Increasing the loss to 10% would bring about an additional year of losses and possible insolvency of the business. However, in this scenario, the losses due to decrease in herd size were offset to an extent by increased sale of hay.
Variable costs that might increase due to predation include herding costs, the need to check on and move animals more frequently, and increased veterinary services. An overall cost increase of 20% to 30%, which is unlikely, would be required to significantly affect profits.
The model shows that predator control activities that achieved a 1% reduction in death loss or a 1% lessening of the affect on weaning weights would be economically efficient. This knowledge can help determine how to best control rangeland predators—whether individually or with state and federal funding.
Full text of the article, “Ranch-Level Economic Impacts of Predation in a Range Livestock System,” Rangelands, Volume 32, Issue 3, June 2010, is available at http://www2.allenpress.com/pdf/rala-32-03-21-26.pdf.
Source : Rangelands