Grazing Behavior and Diet Preference of Beef Steers Grazing Adjacent Monocultures of Tall Fescue and Alfalfa: I. Spatial Allocation

Adjacent forage monocultures are a valuable tool to study the diet preference of grazing animals. Previous research has suggested that cattle will exhibit a partial preference for a legume over a grass regardless of forage species. The objective of this study was to determine if beef steers have a partial preference for alfalfa (Medicago sativa L. subsp. sativa) over tall fescue (Festuca arundinacea Schreb.). These forages have not been evaluated previously as adjacent monocultures. Behavior data recorders, global positioning system (GPS), and pedometers were used to evaluate grazing behavior and diet preference of beef steers grazing tall fescue monocultures or adjacent monocultures of tall fescue and alfalfa at proportions (by ground area) of 50:50, 25:75, and 75:25. Steers exhibited a partial preference for alfalfa, grazing it for 61 to 65% of the time regardless of the proportion offered. A diurnal pattern of preference was not observed. Steers grazing tall fescue monocultures spent more time ruminating (p = 0.02) and tended to graze less time (p = 0.06) than steers in adjacent monoculture treatments. Time spent idling, number of prehensions and mastications, and bite rate were similar (p > 0.05) among treatments. Steers grazing tall fescue monocultures spent less time standing, more time lying, were less active, and took fewer steps (p <= 0.05) than steers in adjacent monoculture treatments. These results support the proposal that cattle have a partial preference for legumes over grasses.