The ultimate trace element supplement for cows & cattle providing up to 6 months of minerals. The Allsure range of intra-ruminal boluses release supplementary iodine, selenium and cobalt for up to 5-6 months. Trace elements are released from the bolus by leaching, providing dietary supplementation. Spent boluses become enlarged and fragile. They are eventually shed, intact or fragmented, by being regurgitated or excreted, usually after 12 months.