Several of our weedy grasses are causing considerable ·trouble to sheep and cattle, particularly in southeastern Iowa where the sheep industry is of considerable economic importance. Not only do these grasses produce mechanical injuries impairing the eye-sight, but the awns and bristles penetrate the skins, gums and throats of animals. The pelts of sheep are rendered worthless in some cases by these mechanical injuries or bring below 50 percent of the normal price. The wool is greatly deteriorated by the presence of plant burs, spines and awns, and may sell for as little as 50 percent of the normal price.
The weedy grasses considered in this circular are poverty grasses, bristly fox-tail, squirrel-tail grass, wild barley and awned brome grass. All of them are common in Iowa.
Pammell, L. H., "Some Weedy Grasses Injurious to Livestock, Especially Sheep" (1929). Circular. Paper 116.