This work was carried out to estimate the retention and the net requirements of Ca and P, in 120 goats averaging 42 kg LW. The estimate retention based in the difference between the total of each mineral stored in the fetus, the uterus, the membranes, the fetal fluids and the mammary gland of animals in the different phases of pregnancy and the total of each mineral stored in the empty goats. The model of prediction used was lnY = A + BX + CX², where X = time of pregnancy. In the comparison of the estimated values and the real obtained values, that the suggested model explained with coherence and precision the biological behavior of mineral retention during all phases of pregnancy. The Ca content during the pregnancy was 38.9 and 78.7 g in the gestation of one and two fetus, respectively, resulting in a daily net requirement of 1.17 and 3.72 g, respectively. The P content was 17.8 and 29.1 g, resulting in a daily net requirement of .48 and .71 g, respectively.
goats; nutritional requirements; pregnancy; minerals; mineral retention
