Effect of Source of Calcium and Phosphorus on Antibiotic Potentiation and Egg Production of Caged Layers

Abstract

DIETARY CALCIUM has been shown to inhibit the absorption of broad-spectrum antibiotics by the domestic fowl (Price et al., 1958, 1959). For this reason, differences in the biological availability of calcium and phosphorus in various dietary supplements have led researchers to investigate their use as broad-spectrum antibiotic potentiators in poultry nutrition.The phosphorus in colloidal phosphate has been shown to have limited biological availability for poultry (Baruah et al., 1960; Gardiner et al., 1959; and Motzok et al., 1957). Evidence is available to indicate the efficacy of dietary colloidal phosphate as an antibiotic potentiator. Camp (1960) substituted colloidal phosphate for dicalcium phosphate in the diet of chicks and obtained approximately twice the level of serum oxytetracycline with diets containing colloidal phosphate. Donovan et al. (1960) obtained an increase in oxytetracycline serum levels when colloidal phosphate was used to replace a part of the dietary dicalcium phosphate.The source of calcium …