Nutrient Removal Rates from Ruminoreticula of Cattle Grazing Kansas Flint Hills Range

Abstract

A Hereford steer and heifer were used to compare rumen removal rates of forage nutrients from Kansas Flint Hills range over a 2-year period. Rumens were emptied after an overnight fast and the contents sampled, weighed, and returned to the rumen. The cattle were then fed a known amount of range forage and fasted for 12 hours, at which time the rumen evacuation procedure was repeated. Removal rate calculations were based on change in rumen contents during the 12-hour fast. All nutrients studied passed the rumen more rapidly during spring and summer months than fall and winter months. Fibrous fractions were removed more rapidly than cell solubles and crude protein, which may indicate that optimum utilization of native Flint Hills range forage is not being achieved. Methods which increase microbial attack of plant cell wall contents may significantly improve livestock production on native rangeland.