BIOLOGICAL AVAILABILITY OF PHOSPHORUS FROM A VENEZUELAN ROCK PHOSPHATE FOR BROILER CHICKS

Three experiments were conducted with broiler chicks to determine the biological availability of phosphorus from a Venezuelan rock phosphate (RRP) and to compare it with that of two other sources, dicalcium phosphate (DP) and monobasic calcium phosphate (MCP). The relative bioavailability of phosphorus from RRP was between 65 and 85% compared to MCP and DP based on the ratio between the slopes of the regression equations for bone ash. The results of these experiments indicate that RRP may be a useful phosphorus source for practical broiler diets. Including RRP or DP in a corn-soybean meal broiler diet as the only source of added phosphate to provide an available phosphorus content of .45% resulted in equivalent growth and higher bone ash in chicks fed RRP.