Managing cows in a drylot can be a way to maintain the herd when forage production is reduced due to drought or as a part of a system when pasture is unavailable for other reasons. When cattle are managed in a drylot over an extended period of time, minerals and vitamins that need to be supplied can vary significantly from those needed when cows are grazing. The most common vitamins and minerals to be impacted by deficiencies or antagonisms when feeding production cows in confinement are Vitamin A, Calcium (Ca), Magnesium (Mg), Copper (Cu), Manganese (Mn), and Zinc (Zn).