A comparative assessment of the potential use of alginates and dietary calcium manipulation as countermeasures to reduce the transfer of radiostrontium to the milk of dairy animals

The potential of using different alginates or supplementary calcium as feed -additives to reduce the transfer of ingested radiostrontium to milk was as sessed in dairy cattle fed a haylage/concentrate diet. The feed-additives c ompared were: calcium alginate (4% by dry matter), sodium alginate (4% by d ry matter) and four levels of supplementation with CaCO3. Both alginates re duced the transfer of radiostrontium to milk by 30-40% without effecting di et palatability. However, the high present cost of alginates precludes thei r use as countermeasures. Dietary calcium supplementation reduced the trans fer of Sr-85 to milk broadly in agreement with previous predictions. From d ata relevant to dairy cattle in the United Kingdom it is suggested that die tary calcium intake could be doubled without exceeding recommended maximum intakes, thus decreasing the transfer of radiostrontium to milk by approxim ately 50%. (C) 2000 Elsevier Science Ltd. All rights reserved.