Effect of Tallow Esters on Ruminal foam Formation in Sheep

Abstract

As part of a study on inhibition of frothy bloat, the inhibiting effect of tallow esters (TE) on frothy bloat was investigated through its in vitro defoaming effect. TE applied in this study were the crude product prepared by subjecting sucrose and beef tallow to alcoholysis using potassium carbonate as a catalyst. Five different levels of concentration (0.25%, 0.5%, 1.0%, 2.0%, control) were used for in vitro study. Rumen fluid was collected from sheep fed a bloat-producing diet. The result of TE addition was that gas production in the rumen fluid during 2hr. of cultivation showed a tendency to increase, and the ingesta volume increase (IVI) also rose simultaneously. However, the stable IVI value, which was used as a criterion for foam stability, was lowered by TE addition (P<0.001). Ruminal pH values were raised by TE addition, and tended to rise as more was added. Though the viscosity of cell-free rumen fluid was not affected by TE addition, the viscosity of cell-inclusive rumen fluid was lowered by TE addition, similarly to the stable IVI value. It is suggested from these results that TE have an inhibiting effect on the occurrence of bloat through the depression of stable foam formation in rumen fluid.