Interactions of Ca, P, Zn, and Alkaline Phosphatase in the Chick. II. Effect of Dietary Ca Level

Abstract

Chicks were fed a semi-purified diet, containing 0.75% Ca, 0.5% inorganic phosphate (Pi), and 50 p.p.m. Zn, to 2 weeks of age. They were then divided into groups and fed the same diet with 0, 0.75, 1.50, 2.25, or 3.00% Ca, for 4 or 7 days before being killed. Plasma was analyzed for Ca, Pi, and Zn, and duodenal mucosa for Ca, Pi, Zn, Mn, and alkaline phosphatase (AP). The low Ca treatment decreased plasma and mucosa Ca and increased mucosa Zn, whereas the high Ca diets increased mucosa Ca and decreased mucosa Zn, plasma Pi, and mucosa AP activity. There was an overall positive correlation of AP with plasma and mucosa Zn, and plasma and mucosa Pi, and a negative overall correlation of AP with plasma and mucosa Ca. Mucosa Mn content did not seem to be related to the enzyme activity.