The Effects of Season and Diet Composition on the Radiocaesium Intake by Sheep Grazing on Heather Moorland

Abstract

In north-east Scotland on a mixed heather and grassland pasture grazed by sheep, 2 × 2 m areas of Calluna vulgaris heath and Deschampsia flexuosa grassland were artificially contaminated with 134 Cs by soil injection. Estimates of the 134 Cs intake by sheep were made on the basis of measurements of dry matter intake, diet composition and 134 Cs concentrations in diet components, assuming that the whole pasture had been contaminated. Dry matter intake by sheep was measured using a natural n-alkane of plant waxes and an orally administered n-alkane as markers. Diet composition was determined by a combination of botanical analysis of samples of ingested material and relationships between n-alkane patterns in faeces and ingested material (...)