Efficacy of Oat Hay as a Legume Bloat Preventive in Cattle

Abstract

Excellent quality oat hay was fed overnight to 17 dry cows, to study its effectiveness in controlling bloat resulting from ingestion of succulent, immature alfalfa pasture. The experiment was divided into the pre-test, test, and post-test periods. Each period was divided into 4 morning and 2 afternoon grazing subperiods. Overnight feeding of an average of 12 lb. of oat hay per cow significantly reduced the incidence and severity of acute legume bloat. The mechanism by which grass hays offer protection from bloat is unknown; however, 3 possibilities are suggested: (1) They physically prevent the formation of froth, (2) they contain a chemical antifrothing agent, or (3) their scabrous nature causes a stimulation of receptors in the rumen responsible for maintaining the tonic activity of rumen motility and eructation by reflex action. Perhaps all 3 factors act simultaneously.