NAF BIOTIN 1.5 KG TUB NAF Biotin also contains methionine, MSM, zinc and calcium to maintain healthy hooves. 50g NAF Biotin provides 15mg biotin. When to feed: For maintenance of hoof integrity. Ingredients: Grass meal Calcium carbonate Saccharomyces cerevisiae (non active) White mineral oil Methionine Dextrin MSM Zinc sulphtate Biotin.