For cattle and sheep ranchers a “stocking rate” reflects how many animals a designated area of acreage will support. The USDA/Agricultural Research Center noted the unpredictability of precipitation causes difficulty for ranchers in the Great Plains to estimate this rate. Scientists use a computer model to assist. By extrapolating seasonal weather predictions, models test scenarios for forage yields and weight gains of livestock under weather conditions. Ranchers are able to better estimate if precipitation will be above or below normal for a given season. This model also determines the effects of increased carbon dioxide and higher temperatures on pasture forage. Testing on the model will continue through the Central Plains.