The first step is to determine the requirements of the cattle. The second step is to determine the mineral content in the forage being fed. Transfer this from a percentage, which appears on most forage analysis sheets, to grams as follows: i.e., 20 pounds dry matter intake x 0.002% phosphorus x 454 grams = 18.2 grams. Then compare the daily dietary intake to the requirement. (Note: 454 grams = 1 lb. and the forage is .20% P so to make the percentage into a decimal move the decimal two places to the left)