A sustained release bolus containing six trace elements and three vitamins. Designed for grazing or forage fed dry dairy cows and dairy heifers with a liveweight over 400 kg. helps farmers manage the trace element status of their herd during the dry period. During the dry period cows tend not to receive any form of supplementary feeding and, in some cases, the nutritional status of the animal is allowed to deteriorate to such an extent that the vital periods of calving, onset of lactation and conception can be compromised. Given this, it is important to maintain trace element levels as the dry period is a recovery phase and a period of rapid embryo development.