Acid-Base Balance and Sodium-to-Chloride Ratio in Diets of Laying Hens

Abstract

The effect of dietary sodium and chloride on blood pH, pCO₂, HCO₃^-, Cl^- and Na⁺ was evaluated in laying hens during shell formation. Blood pH and HCO₃^- were a function of the dietary Na/Cl ratio, regardless of the total concentration of the two ions in the diet. With a constant dietary level of chloride, alkalosis was produced with NaHCO₃, Na₂SO₄, CH₃COONa, and NaH₂PO₄ as dietary sodium supplements. Conversely, with a fixed level of dietary sodium, acidosis was produced by CaCl₂, FeCl₃, KCl and choline Cl as chloride supplements. The possible mechanism for the acid-base response to the dietary Na/Cl ratio and its possible nutritional significance are discussed.