Availability of Phosphorus in Soft Phosphate and Phosphoric Acid and the Effect of Acidulation of Soft Phosphate

A CONSIDERABLE amount of evidence is available in the literature phate as compared with other phosphate sources for feeding to poultry. Gillis et al. (1951) found that samples of bone meals, dicalcium phosphate, defluorinated phosphates and Curacao Island phosphate showed some variation but generally very satisfactory phosphorus availability. On the other hand, a large number of samples of colloidal phosphate showed poor availability. Miller and Joukovsky (1953) found that dicalcium phosphate, Curacao Island phosphate, bone meal and defluorinated rock phosphate were all readily available sources of phosphorus. The phosphorus in colloidal phosphate was found to be less than 50% available as compared with other phosphate supplements tested. Grau and Zweigert (1953) found that phosphatic clay was not as good a source of available phosphorus as bone meal or tricalcium phosphate when fed to chicks on a practical ration. Gillis and co-workers (1954) reported that the phosphorus in colloidal phosphate was …