Fertilization Influences Cattle Diets on Blue Grama Range During Drought

Abstract

Botanical composition of cattle diets on fertilized and unfertilized blue grama rangeland was evaluated during drought by microhistological examination. Seventy-two percent of all species available were found in the diets. Grass comprised 62% of the yearly diets on the fertilized pasture compared with 73% on the unfertilized pasture. Annual forbs made up 18% of the diets on the fertilized pasture and 8% on the unfertilized pasture. There were no differences in perennial forb composition of the diets among the two pastures. Total grass consumption did not vary among seasons, but composition of individual species did. Blue grama provided the bulk of grass in summer and fall diets with mat muhly furnishing the majority of grass in diets during winter and spring. Perennial forbs were important in winter and spring diets. Annual forbs were major components of diets during summer and fall. Cattle consistently exhibited a greater preference for fertilized blue grama than for unfertilized blue grama. Preference trends for other plants were inconsistent and were influenced mostly by availability.