Effects of stocking rate on quantity and quality of available forage in a southern mixed grass prairie

Abstract

The objective of this study was to quantify the long-term (25 years) effects of heavy (HC) and moderate (MC) rates of stocking on quantity and quality of forage available. Study design required frequent harvest of standing crop on 5 range sites in twice replicated, 244 ha treatment pastures. Results from the 20-month study showed aboveground standing crop dynamics were similar in both treatments, quantity of available forage was greater in the MC than HC treatment, quality of available forage was greater generally in the HC than MC treatment, and that heavy stocking favored a dominance of warm-season shortgrasses as opposed to a dominance of warm-season midgrasses. Averaged across dates and adjusted for differences among pastures in range site composition, aboveground herbaceous standing crop averaged 1,341 kg/ha in the HC pastures as compared to 1,816 kg/ha in the MC treatment pastures. Crude protein and organic matter digestibility averaged 8.6% and 49.3%, respectively, in the HC pastures and 7.7% and 46.7%, respectively, in the MC pastures. It is concluded that the greater variation among years in cow/calf production in the HC than in the MC treatment is primarily because forage availability in the HC treatment is less than in the MC treatment.