Nutritive Value of Forage and Diets of Sheep and Cattle from Oregon Subclover-Grass Mixtures

Abstract

During spring-summer over a three-year period, selectivity by both sheep and cattle grazing on subclover-perennial ryegrass and subclover-tall fescue resulted in higher nutritive value of diets than of ungrazed forage. Sheep diets consistently contained more crude protein and had higher in vitro dry matter digestibility than did cattle diets. Both sheep and cattle diets were more digestible under light than under heavy grazing but diet protein levels were inconsistent. In one year stocking rate had no effect on level of protein in the diet and the next year high protein levels were associated with heavy use. Summer vegetative regrowth of tall fescue caused by heavy cattle grazing resulted in levels of dietary protein for cattle similar to those for sheep. The level of dietary protein for sheep exceeded recommended requirements. In the summer, protein levels of cattle diets were near or below requirements except when cattle heavily grazed subclover-tall fescue pastures.