Measuring Selective Grazing with Fistulated Steers

Abstract

Four grazing trials were conducted during 1958, with three on a Kentucky bluegrass-white clover pasture and the other on a tall fescue-Ladino clover pasture. Steers with either rumen or esophageal fistulas were used to sample the forage at two- to three-day intervals. Selective grazing was exhibited on the pasture studies. Botanical analysis indicated in all cases that grass increased in the grazing animal's diet as the period progressed and, conversely, clover decreased. Protein decreased and crude fiber increased in fistula samples, with respect to time, even though the chemical composition of clipped samples remained fairly constant. The composition of fistula samples failed to agree with the composition of samples hand-harvested from under cages the same day. © 1960, American Dairy Science Association. All rights reserved.