This experiment was carried out to study the effect of different levels (3.06, 3.23, 3.4, 3.57 and 3.74%) of calcium and vitamin D3 (2000, 2200 and 2400 IU/kg diet) on eggshell quality of laying hens. In a completely randomized design and in a 5×3 (15 treatments) factorial arrangement, two hundred and forty (240) white leghorn laying hens, strain Hy-Line W36 and 26 weeks old, were divided into ...