Phosphorus deficiency in cattle from the Brasília region of Brazil

Abstract

Young male cattle were studied under range conditions in four “cerrado” areas of Brasilia (Sobradinho, Planaltina, Formosa and Luziânia) for a period of 14 to 21 months. Serum inorganic phosphorus values were determined at monthly intervals during this period. At the same time analyses of phosphorus in grass samples of Melinis minutiflora, Hyparrhenia rufa and Aristida sp., and also soil analyses were carried out. The results of the serum inorganic phosphorus estimations from cattle in the areas of Sobradinho and Planaltina were in agreement with the herd histories, which indicated that the Sobradinho area was not deficient in phosphorus and that the Planaltina area was deficient in phosphorus. In the areas of Formosa and Luziânia, the serum inorganic phosphorus levels were intermediate, and also are in agreement with the herd histories, which indicated a moderate phosphorus deficiency. There was a significant correlation between the phosphorus values in the blood serum and the values of the three grass species with the exception of also area where there was the most severe phosphorus deficiency. There was a correlation between the phoshorus values of the soil and the yearly average serum inorganic phosphorus value of the cattle from all four areas. No correlation was found between rainfall and inorganic phosphorus levels in the blood serum in phosphorus deficient areas, but in the area where there is no phosphorus deficiency there is a close correlation between increased rainfall and increased inorganic phosphorus in the blood serum.