Mineral supplementation with phosphorus and sodium was tested in cow-calf operations located in deficient areas as regards the minerals mentioned above in Mercedes, Corrientes, Argentina. Supplementation was carried out in three farms for 4 years: 176 observations for the supplemented group and 155 observations for the unsupplemented group were performed. 59% pregnancy rate was obtained in the supplemented group, however, 44% was obtained without supplementation. This result was financially advantageous for the producers.
