Effect of Light on Economic and Physiological Characters of Laying Hens ,

Abstract

THE influence of light on reproduction in birds has been reported recently, and reviewed by King (1961), Lanson and Sturkie (1961), Morris and Fox (1960), Fox (1961), Shutze et al . (1961), Bowman and Jones (1961), Lowe and Heywang (1961), and Farner (1961). McClary (1960a, b) reported that he was able to increase egg production and egg size by increasing the day length at hatching time approximately 51/2 hours beyond that which would be available under natural conditions at 22 weeks of age, then gradually decrease the day length 51/2 hours during the rearing period, followed by an abrupt or gradual increase in day length in the laying house. The experiment being reported was designed to determine if a reduction in day length from 22 hours at hatching to 16 hours at 20 weeks of age was comparable in enhancing production to a decrease in day length from 16 to 9 …