The effect on egg shell quality of supplementing saline drinking water with sodium or ammonium bicarbonate

Abstract

Supplementing the town water supply of laying hens with 600 mg sodium chloride (NaCl)/L significantly decreased egg shell quality and significantly increased the incidence of egg shell defects without affecting egg production and egg weight or food and water intakes. A smaller, but still significant, increase in egg shell defects was also observed with sodium bicarbonate (NHCO3) supplementation of town water. Ammonium bicarbonate (NH4HCO3) supplementation of town water had no significant effect on egg shell defects and, when added to drinking water containing NaCl, significantly reduced the incidence of shell defects. A smaller beneficial effect was observed when NHCO3was added to saline water. Ammonium bicarbonate, when added to saline drinking water at concentrations of 250 and 450 mg/L, reduced water intake, an effect not observed when these same supplements were added to town water. This suggests that the presence of NaCl in the water may affect kidney function so that the use of NH4HCO3may have limited value, especially at higher water salinities. Shell gland fluid composition was influenced less by treatment than by whether or not hens were laying eggs with defective shells.