The Availability of the Phosphorus in Dicalcium Phosphate, Bonemeal, Soft Phosphate and Calcium Phytate for Mature Wethers

Abstract

Studies are described in which the availability (true digestibility) of the phosphorus in dicalcium phosphate, bonemeal, soft phosphate and calcium phytate was determined by the isotope dilution method with mature wethers. The true digestibility of the phosphorus in the supplements was 50, 46, 14 and 33 per cent for dicalcium phosphate, bone-meal, soft phosphate and calcium phytate, respectively. Although significantly less phosphorus was absorbed from the soft phosphate than from the other supplements, the phosphorus retained from the basal ration plus soft phosphate was equal to the others. The surplus phosphorus absorbed from the rations containing the other supplements was excreted by way of the metabolic fecal phosphorus. Significantly less phosphorus was absorbed from calcium phytate than from dicalcium phosphate and bonemeal.