Physical Characteristics,Shade Distribution,and Tall Fescue Effects on Cow Temporal/Spatial Distribution in Midwestern Pastures

Nonpoint source (NPS) pollution of water resources may occur from congregation of cattle near streams or ponds. Therefore, relationships of physical characteristics, shade distribution, and tall fescue (Festuca arundinacea Schreb.) prevalence in cool-season grass pastures to the temporal/spatial distribution of grazing cattle were evaluated in two studies on beef cow/calf farms. Global positioning system (GPS) collars recorded the location of 2–3 cows per pasture at 10-min intervals for 5–14 d in the spring, summer, and fall annually. Pasture botanical composition was visually assessed annually. In Study 1, cow location was recorded on five pastures ranging in size from 13 ha to 125 ha with 1.9–3.8% of the pasture area in a stream or pond (water source) and 2–30% of the pasture area within 30.5 m of the water source (waterside zone) for 3 yr. Shade covered 27–73% of the pasture area with 3–64% of shade located within waterside zone. In Study 2, cow location was recorded in three pastures with areas of 8 ha, 10 ha, and 15 ha with 17.8%, 43.4%, and 14.7% of the total area and 28%, 73%, and 68% of the total shade in the waterside zone for 1 yr. In Study 1, proportions of cow observations within the waterside zone increased with decreasing pasture area (r² = 0.61) and increasing proportions of the total pasture area (r² = 0.37) and shade (r² = 0.29) within the waterside zone. In Study 2, proportion of cow observations in the waterside zone increased as the proportion of total area (r² = 0.62) and shade (r² = 0.42) in the waterside zone increased. Results imply more restrictive measures to minimize the risks of NPS pollution of water resources may be most effective in smaller and narrow pastures.