Effect of Feeding Natural Zeolite on Performance of Laying Hens Drinking ‎Saline Water

This experiment was conducted to determine the effects of dietary natural zeolite on performance of laying hens receiving saline drinking water (2g NaCl/L). One hundred and twenty 49 weeks old laying hens were randomly assigned (two birds per cage) to 60 cages in a naturally ventilated laying house. Six treatments were examined over a 28-day period. Control hens received town water and a commercial layer diet (TW-LD). Hens of treatment 2 were given town water and were fed a commercial diet supplemented with 10 g/Kg natural zeolite (TW-Z10). The remaining four treatments received the water containing 2g NaCl/L (SalW-) and a commercial diet supplemented with 0, 10, 20, and 30g/Kg natural zeolite for treatments 3 (SalW-LD), 4 (SalW-Z10), 5 (SalW-Z20), and 6 (SalW-Z30), respectively. To account for differences in the amounts of added zeolite, sand was added to the diet in order to keep the resulted diets isoenergetic. Egg production, egg weight, egg mass output, daily water intake feed consumption, feed conversion, and eggshell quality parameters were measured. No significant treatment effects were observed with percentage egg production, egg weight, egg output, feed conversion and feed consumption among the different treatments. However, water intake for hens in treatment 5 was significantly higher than that of hens in the remaining treatments. Significant differences between treatments were observed with regard to all shell quality measurements other than egg specific gravity. Saline water caused a significant reduction in shell thickness, shell weight: egg weight, and shell weight per unit surface area. Addition of natural zeolite (10 to 20g) improved eggshell quality parameters especially for hens receiving saline water.