The in vitro digestibility of oesophageal fistula samples after washing for botanical separation

Abstract

An in vitro digestibility technique was used to compare the digestibility of washed and unwashed portions of plant material collected from the oesophageal fistulas of grazing sheep. The digestibility of a washed portion was 5.5 to 8.2 digestibility units lower (P<0.05) than that of an unwashed portion of the same fistula sample. The grasses used in the study were Panicum coloratum L., Paspalurn dilatatum Poir., Eragrostis curvula Nees-var. valida Stapf., Sorghum almum Parodi, and Chloris gayana Kunth. The presence of some dry matter in the Panicum plots and the relatively low acceptability of the Eragrostis appeared to cause variation in the results due to selective grazing by the sheep. It was concluded that a correction of five digestibility units would make washed portions of fistula samples collected from grazing sheep useful in evaluating the quality of pasture species from mixed swards.