The effect of progressive grazing of a pasture on the spatial distribution of herbage mass and utilization by cattle

To develop an understanding of the spatially heterogeneous grazing of a pasture by large herbivores under progressive grazing, the herbage mass, herbage consumption and ingestive behavior by cattle were monitored daily at ninety-one 50 H 50 cm permanent locations in a bahiagrass (Paspalum notation Flugge) pasture during a 6-day grazing period. With the progress of grazing, the mean pre-grazing herbage mass over the locations decreased. Responding to this, the mean number of visits and the mean rate of biting increased, and-the mean residence time and the mean rate of defoliation decreased. The pre-grazing herbage mass became more heterogeneous, whereas the number of visits and the rate of defoliation became more homogeneous, based on the coefficient of variation. The overall spatial heterogeneity was ranked: rate of defoliation > number of visits greater than or equal to residence time greater than or equal to pre-grazing herbage mass > rate of biting. The results have provided some new information about the spatially heterogeneous grazing by cattle in a monospecific grass pasture, though further analyses and studies are necessary for fully understanding the mechanisms behind the diverse responses of the spatial heterogeneity of the variables to grazing.