Productivity of Cool-Season Perennial Pastures Under Cattle Grazing Initiated at Three Stages in Spring Following Moderate and Heavy Fall Defoliation.

The decision of when to allow cattle to begin grazing perennial cool-season grass-legume pastures in the spring is often based on a goal of minimizing hay-feeding in year-round pasture systems. Impacts of initiating grazing at different plant developmental or physiological stages on subsequent pasture growth are not well-defined in many areas including the Appalachian region. We tested the hypothesis that total-season herbage production is maximized when spring grazing is initiated at a stage of approximately 2.5 fully-elongated grass leaves and sward height of approximately 10-12 cm. We initiated rotationally-stocked cattle grazing at this stage in mid-April, plus at stages 10 days earlier and 10 days later than this stage. In each case, spring grazing treatments followed fall grazing of stockpiled herbage that left moderate and low levels of residual herbage mass. Total-season herbage production responses to spring and previous fall grazing treatments will be summarized and discussed.