Phosphate Supplements of Different Fluorine Content as Sources of Phosphorous for Chickens ,

THE substitution of vegetable protein concentrates, with their low mineral content, for a large part of the animal products formerly used in poultry rations makes it necessary to add minerals to supplement these vegetable products. Although steamed bone meal has been used as a common source of phosphorus, some other sources of phosphorus might be as satisfactory. Among these are rock phosphate, superphosphate, and partly defluorinated phosphates. These supplements contain more or less fluorine which has been demonstrated to be deleterious to livestock when fed in excessive amounts Raw rock phosphate has been used in rations for poultry by Wheeler (1903), Hartwell and Kirkpatrick (1911), Lewis (1913), Kennard, Holder, and White (1922), Buckner, Martin, Pierce, and Peter (1922), Buckner, Martin, and Insko (1929), and Halpin and Lamb (1932). Results were inconsistent but in general indicated that phosphorus from animal bone was preferable. Haman, Phillips, and Halpin (1936) reported an increase . . .