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The accident at the Chernobyl nuclear power plant in 1986 resulted in levels of radiocaesium in animal-derived food products above national intervention limits in a number of countries. In upland areas of the United Kingdom (UK) radiocaesium activity concentrations in the meat of some sheep exceeds (in 1998) the local intervention limit of 1000 Bq kg−1 and measures are still in place to restrict the entry of such animals into the human food chain. The use of many established countermeasure techniques is difficult due to the nature of animal management in the affected areas. This paper describes a study to develop and test a bolus containing the radiocaesium binder ammonium ferric hexacyanoferrate (AFCF) suitable for administration to small lambs of hill-sheep breeds used in the UK. It was found that a bolus 14 mm × 50 mm in size, and containing 20% AFCF, could be safely administered to lambs of 10 kg. An increase in the AFCF content above 20% resulted in too rapid a breakdown of the bolus. Administration of three boli per lamb reduced the 137 Cs activity concentration in muscle by circa 50% between 3 and 8 weeks following administration of the boli. After 12 weeks the reduction in the 137 Cs activity concentration was 30%. We conclude that the AFCF bolus developed could be effectively used to reduce the radiocaesium activity concentration in lambs within hill and upland areas of the UK.

SUMMARY Tests indicate that, following selenite enrichment, Salmonella dublin would be isolated from rectal swabs taken from animals excreting 100 S. dublin organisms/g faeces. Even lower numbers of excreted organisms should often he detected. Thirty-eight of 183 calves under three months old examined post mortem yielded S. dublin and seventeen (44 · 7 per cent) of the thirty-eight gave cultures of S. dublin from rectal swabs. In three cases, rectal swabs were positive from calves with negative intestinal cultures, and on four occasions the reverse was true. In fourteen cases both rectal swabs and intestinal cultures were positive. S. dublin appears to be excreted in the saliva of sick calves.

SUMMARY A killed toxoplasma vaccine prevented foetal death in a proportion of ewes which were challenged during subsequent pregnancy; it did not prevent foetal or placental infection. Pregnancy was more frequently normal in those ewes with higher dye-test antibody titres at the time of challenge. Also, the earlier in pregnancy the challenge was given, the greater was the likelihood of foetal death. Ewes which had dead lambs had higher post-partum antibody titres than those which had live lambs. The indirect fluorescent antibody test proved to be the most sensitive method for demonstrating infection in the products of conception. Histopathological changes were predominantly in the placenta; only minor lesions were found in the dead lambs and these were no more severe than in the lambs born alive.