Feeding phosphorus above current NRC (2001) recommendation does not improve reproductive performance. Earlier studies indicated a relationship between dietary phosphorus and reproduction, but phosphorus levels in those studies were close to 0.20% of the diet dry matter. It is important to note that feeds commonly used in dairy diets have greater phosphorus concentrations, usually yielding diets containing in excess of 0.30%, or even 0.40%, phosphorus in the diet dry matter without the addition of phosphorus supplements. The majority of dairy diets need little, if any, mineral supplementation of phosphorus to meet lactating dairy cows’ requirements.
Vinicius R. Moreira, LSU AgCenter Southeast Research Station
