A bolus is a complimentary feed that is becoming more and more popular since it’s an easy and economical solution to enrich an animals diet. With only one bolus the vitamin and mineral requirements of the herd are covered for a few hours up to six months. A bolus should be given orally. In the rumen this bolus will release its vitamins and minerals through erosion with fodder and dissolution in the rumen liquids. Depending on the goal of the bolus these elements will be absorbed by the rumen and/or intestines. To ensure an adequate intestinal absorption elements may come in chelated form.