Effects of Varying Amounts of Calcium and Phosphorus in Rations for Dairy Cows

Abstract

Abstract Different dietary percentages and ratios of calcium and phosphorus were studied with 48 dairy cows in a randomized block design. The respective members of each block were assigned to one of three ration treatments: a) Ca: P ratio approximately 3:1, 0.4% phosphorus; b) Ca:P 3:1, 0.6% phosphorus; and c) Ca:P 1.5:1, 0.6% phosphorus. Response criteria were blood mineral concentrations, milk yield and composition, parturient paresis, and reproductive performance. Average blood serum inorganic phosphorus was lower (P