Application of the double-marker method for measuring digesta kinetics to rumen sampling in sheep following a dose of the markers or the end of their continuous infusion

Abstract

Methods are described by which the double-marker method for measuring digesta kinetics may be applied to rumen samples taken from sheep maintained in steady-state conditions, while marker concentrations are declining after a single dose of the two markers, or cessation of their continuous infusion, or increasing in the pre-equilibrium phase of their unprimed continuous infusion. Also described are procedures for checking the consistency of analyses applied to digesta, fluid-phase and particle-phase samples and for physically reconstituting true digesta samples. Errors due to deviations of the markers from ideal behaviour are examined.