The effect of ammonium ferric hexacyanoferrate on reducing radiocaesium transfer from grass silage to sheep

A study was carried out to examine the effect of ammonium ferric hexacyanof errate (AFCF) on the transfer of radiocaesium from grass silage to the tiss ues of male lambs. During ensiling, a formic acid based additive and AFCF w ere sprayed on grass contaminated with Cs-134 and the mixture was allowed t o incubate for 45 days. A dose of 21 mg AFCF d(-1), fed to sheep offered co ntaminated silage for fourteen days, reduced Cs-134 transfer to muscle by 4 5% compared to that of control sheep. An equivalent dose of AFCF administer ed in a capsule reduced transfer by only 3%. In another experiment, AFCF in take of 50, 100 and 150 mg d(-1) for ten days reduced Cs-134 transfer to sh eep muscle by 75, 82 and 86%, respectively. In control lambs, of average li ve weight 38 and 47 kg, the feed to muscle Cs-134 transfer coefficient aver aged 0.15 d kg(-1), but equilibrium between tissue and feed Cs-134 had prob ably not been reached due to the short feeding period. Increasing doses of AFCF from 0 to 150 mg d(-1) increased the faecal/urinary Cs-134 ratio from 2 to 42.