Abstract
The dispersion of heifer excreta in a flat and square pasture (1 ha) surrounded by fences with a watering place on an edge was examined, and the relationships between the excretal density of a site and its distance from the watering place were derived as decreasing exponential functions. Dispersion patterns of dung and urine in a pasture with the same shape as the above field were simulated by using the above mentioned relationships to clarify the formation process of excretal dispersion pattern. It was proved not only that grazing equipments, e.g., watering place, cause uneven excretal dispersion, but also that, when the spatially biased densities are formulated mathematically, the uneven dispersion of excreta can be expressed by the Poisson model.
