Animal performance and diet quality as influenced by burning on tallgrass prairie

Abstract

Burning on good to excellent condition tallgrass prairie in central Oklahoma yielded results which visually appeared much greater than would be expected from previous burning research. Therefore, a study was designed to quantify the effect of burning on plant and livestock responses. During 1984-1986, average daily gains of stocker cattle were monitored from late May to mid-October in replicated burned and unburned pastures. Stocking rates varied from 0.8 to 1.5 ha per animal depending on initial animal weights. Fistulated cattle were used to monitor diet quality on the pastures. Standing crops were measured at the end of the growing season (early October) in exclosures, and at the end of the grazing period (late October) in the pastures. Animal performance was improved by burning during the early part of the grazing season, and over the season animal production per ha averaged 11.2 kg higher on burned compared to unburned pastures. Dietary crude protein tended to be higher on unburned compared to burned pastures, but the opposite was true for in vitro organic matter digestibility. Standing crop remaining after the grazing period averaged 4,304 and 2,539 kg/ha for burned and unburned pastures, respectively. Standing crop was 57% higher in burned compared to unburned exclosures. Burning caused a shift in species composition to favor tallgrass species and lower production of weedy forbs in both exclosures and grazed pastures.