Forage selection by cattle on fescue prairie in summer or winter

The rough fescue grasslands are important for livestock grazing as well as other values such as wildlife habitat, recreational opportunities, and watershed properties. The impact of livestock on these grasslands must be better understood in order to manage grazing for optimal use of the resource. A study was conducted from 1992 to 1994 on the rough fescue grassland near Stavely, Alberta, to determine forage selection by cattle in the winter and summer and the effect of canola supplementation on forage selection. Twelve 1.7-ha paddocks were stocked with 2 cows (Hereford) at 3.2 animal-units-months ha-1 in winter; canola supplements (0.0, 0.4, 0.8, and 1.2 kg animal-1 day-1) were applied in a randomized complete block design. Three additional 1.7-ha paddocks were similarly stocked but grazed in the summer with out canola supplements. Forage availability, utilization, and relative preference were estimated for 4 major plant species. In both winter and summer, rough fescue (Festuca campestris Rydb.) was utilized most (P < 0.05) and Idaho fescue (Festuca idahoensis Elmer) and smooth aster (Aster laevis L.) were utilized the least. Of total forage utilized, rough fescue and Parry oat grass (Danthonia parryi Scribn.) contributed about 90 and 9%, respectively, in winter and about 62 and 32%, respectively, in summer. In summer, Parry oat grass was utilized in proportion to its availability. Rough fescue was the preferred species in both winter and summer. Percent forage utilization in winter was not affected by supplementation with canola. The high preference for rough fescue appeared to be determined by the accessibility of the large tufted plants to cattle. This was particularly evident in winter when access to plants was impaired by snow cover. Successful winter grazing on these grasslands is enhanced with a large proportion of rough fescue plants in the stand.