The Effect of Carbon Dioxide Inhalation and Sodium Bicarbonate Ingestion on Egg Shell Deposition

Abstract

Helbacka et al. (1963) reported that exposure of laying hens to an atmosphere containing 5 percent carbon dioxide for 24 to 48 hours led to a marked decrease in the calcification of the shell. They suggested that deposition of calcium carbonate is dependent upon blood pH and is depressed when blood pH is lowered either by respiratory acidosis or by ammonium chloride feeding (Hall and Helbacka, 1959). This suggestion that depressed deposition of calcite follows low blood pH, independent of arterial carbon dioxide tension, is difficult to reconcile with results obtained with mammalian species. Freeman and Fenn (1953) found that rats chronically exposed to high levels of inspired carbon dioxide displayed hypercalcification of the bone, calcite being the major mineral component deposited in excess over the normal. Schaefer et al. (1963) exposed subjects chronically to 1.5 percent carbon dioxide and suggested that the disturbance noted in calcium metabolism was dependent…