Bloat in cattle

Abstract

Four quantities which assist in characterising persistent strong foams produced from proteins, plant extracts, or rumen liquor are described. Two are derived from foam drainage data by applying the second order relation dv/dt = k₂ (v∞ —v)². They are drainage constant, k₂, and foam retention volume, _vº — v_vºº. The remaining two quantities are physical properties determined by the effect of the foam on a sensing disc connected to a strain gauge. They are compressive strength and stress relaxation. The reproducibility and variation of these quantities within a range of experimental conditions are given, and their possible interdependence and relationship to foam persistence are considered.