Daily selection of feeding areas by cattle in homogeneous and heterogeneous environments

Abstract

Yearling steers were observed in a two-part study to evaluate movement patterns in homogeneous and heterogeneous areas. Previous grazing and fertilization were used to create three heterogeneous patches that varied in forage quality and quantity. Three homogeneous patches were also established. Two groups of steers were released daily from a holding pen and allowed to choose within either the homogeneous area or the heterogeneous area. During the first trial, steers selected patches from a central decision area, and fences divided the patches. During the second trial, division fences were removed. No patch preferences developed in the homogeneous area if data were pooled within a day. However, time spent in patches was not consistent throughout the day. Steers grazed patches nearest to water during midday, but avoided those patches during the morning and evening. Animals developed preferences for the most nutritious patches, as indexed by crude protein concentration, in the heterogeneous area. They avoided a patch with lower forage quality for 21 consecutive days. Cattle tended to return to a particular patch more often in the heterogeneous area, but in both the heterogeneous and homogeneous areas, animals returned to the same patch on consecutive mornings less than 48% of the time. Cattle moved among patches more frequently in the homogeneous area during Trial 2 after fences were dismantled. One or two individuals may have influenced the initial patch selection for the remainder of the group. Uneven grazing distribution patterns associated with cattle grazing heterogeneous environments may occur because they select feeding areas with higher forage quality more frequently than feeding areas with lower forage quality.