this experiment was carried out to study the effect of manganese in four levels (30, 60, 90 and 120 mg/kg) and zinc in four levels (50, 100, 150 and 200 mg/kg) on shells with translucent areas, haugh unit, mortality, percentage of ash in eggshell and composition of eggshell in laying hens, in a completely randomized design and in a 4×4 (16 treatment) factorial arrangement, three hundred and twe...