An incubation tray is disclosed, including an enclosure with a plurality of egg placements for carrying eggs for incubation within an egg incubator. The incubation tray includes a tester unit including plurality of inspection modules in the enclosure associated with the plurality of egg placements. The inspection modules, each includes radiation emitter(s) and sensor(s), and are configured and operable for respectively inspecting the plurality of eggs located in the egg placements, by irradiating the eggs with radiation from a lateral side of the eggs and measuring a radiation response coming in response to the irradiation from a lateral side of the eggs, giving rise to measured data indicative of conditions of the eggs. The measured data may be processed to determine dynamic and static parameters of the radiation response from which a physiological development stage, and growth of the embryos within the eggs can be estimated.
