Phosphorus absorption and availability in swine rations based on natural phosphates

Abstract

The natural sources of phosphares have been studied in zootechnical researches in Brazil recently because of the high price of the bicalcium phosphate, which is about ten times more expensive than the rock sources. For a best evaluation, the phosphate needs to be known as for the biological availability. The objective of this experiment was to study the phosphorus (P) metabolism in swine using four natural phosphates. The experiment was carried out with 20 piglets weighing at beginning 21.16 ± 0,89 kg, distributed in five treatments: Goiás, Patos and Tapira phosphates, bone meal, and the control without P supplementation. The animals were kept in metabolic cages, receiving the feeding based on metabolic weight. Each piglet received a dose of 500 µCi of ³²P, as sodium phosphate, to determine the endogenous P, using the isotope dilution method. The rates of true absorption in the diets supplemented with Goiás, Patos and Tapira phosphates, bone meal and control were 55.83%, 60.68%, 60,39%, 61,14% and 66.26%, respectively, without significant differences (P>0.05). For the same phosphates, except for the control, the availability of the supplementar P, was: 37.56%, 44.30%, 47.82% and 46.34, respectively. The above values can be used to calculate diets with available phosphorus.