The Influence of Light and Darkness Upon the Reproductive Performance of the Fowl

THE use of supplemental light to stimulate winter egg production by providing a 13 to 14 hour day has been reported by many investigators, but no method of lighting hens in production has been developed that will consistently improve egg production for the entire year (Dougherty, 1922; Kable, Fox and Lund, 1928; Smith, 1942; and Eramus, 1955). More than 13 hours and even 24 hours of light per day do not consistently improve egg production (Kennard and Chamberlin, 1931; Penquite and Thompson, 1933; and Moore and Mehrhof, 1946). Egg production can be maintained, but at a reduced rate on as little as 11 hours of light (Dobie, Carver and Roberts, 1946). Chickens, once in production, can lay at a low rate for at least as long as four weeks if given but six periods of one minute of light per day (Wilson and Abplanalp, 1956). Caged chickens, also once in…