Evaluation of the availability of phosphorus from dicalcium phosphate and rock phosphates for sheep, using radiophosphorus (³²P) as tracer

Abstract

In the present experiment the phosphorus availability from dicalcium phosphate and rock phosphate from Patos de Minas, Tapira and Finos de Tapira was determined, by the radiophosphorus dilution technique. Twenty-four male sheep received a semipurified diet and the phosphate sources were added to give 4 g P per day. After two weeks each sheep was injected intravenously with 7,4 MBq of ³²P and blood and feces samples were collected at 24 hs intervals for 8 days. The specific activities of plasma and feces were determined. True absorption values were 58.92; 50.85; 47.99 and 42.72% for dicalcium phosphate, Finos de Tapira, Tapira and Patos. Rock phosphate availabilities were high in relation to dicalcium phosphate.