DIETARY-INTAKE OF RADIOCESIUM BY FREE-RANGING MOUNTAIN SHEEP

The vegetation composition of the diet of mountain sheep was determine d by faecal fragment analysis. A comparison of diet composition with t he vegetation available for grazing revealed selection by sheep of gra sses, in preference to the more abundant shrubby vegetation. The radio caesium content of the diet and of the available vegetation was determ ined and compared with sheep in-vivo radiocaesium levels and sheep fae ces radiocaesium activities. This approach demonstrated the importance of diet selectivity by sheep in determining dietary intake of radioca esium. Faeces radiocaesium activity was shown to be more appropriate t han vegetation radiocaesium activity as a predictor of in-vivo radioca esium activity in free ranging mountain sheep.