Let there be light ... and dark

摘要

Can lighting programs using daily light and dark periods enhance the immune system of broilers? Recently, a large number of articles on melatonin have been publisbed in the popular press and newspapers, as well as scientific journals. Melatonin is a hormone produced by the pineal gland of humans and animals, including poultry. The pineal gland is a very small structure located on the top of UK brain in chickens. Being just under the skull and about in the center of the top of the head, it receives, and is influenced by environmental light. Light inhibits melatonin production and darkness stimulates it. In daily light-dark cycles, melatonin is low during light and high during dark periods. Therefore, animals, including broiler chickens, which are exposed to continuous lighting will be severely deft-drat in serum melatonin.