Grass utilization and grazing distribution within intensively managed fields in central Alberta

Abstract

Grazing distribution and grass utilization was evaluated in intensively managed fields in the southern Aspen Parkland near Kirriemuir, Alberta. Three fields, 130 ha in size (with dimensions .4 X 3.2 km) were grazed by 1,000 cow/calf pairs for 5 days each. Stock water was accessible only from one end of each field. Grazing distribution was evaluated by monitoring grass utilization daily during grazing and after grazing at 0.1, 0.8, 1.6, 2.4, and 3.1 km from water. Final utilization did not differ within fields, except for a decline at the maximum distance from water (3.1 km). Temporal utilization patterns existed and could best be described as a wave, with defoliation beginning near the water source on day 1 of grazing and proceeding outward from water until the ends of the fields were grazed on day 5. Final utilization was uniform; selective grazing of areas close to water was not removed by intensive management, but was masked by a rapid rate of defoliation.