The use of an in vitro technique to predict the absorption of dietary radiocaesium by sheep

The validity of an in vitro extraction technique
to predict the availability for absorption of radiocaesium
in the sheep gut has been assessed. The technique (a 2-h
extraction with caesium chloride) was found to be valid for
sources with a low availability for transfer across the gut,
but inappropriate for ionic radiocaesium or radiocaesium
incorporated internally within herbage. For such radiocaesium
sources, which have a high in vitro availability, no
correlation was found between in vitro extraction and true
absorption measurements. A true absorption value of 0.80
is recommended for these sources, although values for individual
sheep in the range 0.60 to 1.00 should be expected.