Increasing Egg Production in Winter-Hatched Turkeys by a Restricted Light Treatment

A SHORT daily light restriction given to fall or early-winter-hatched turkeys prior to maturity will, by virtue of disrupting hypothalamic refractoriness to seasonal increases in day light, decrease age at first egg and improve rate of lay (Marr et al., 1956; Harper and Parker, 1957). More recent investigations indicate that successful light restriction programs are dependent upon four factors: 1) length of the daily light period; 2) duration of the imposed daily light restriction; 3) age of the females at time of light restriction; and 4) total daily hours of stimulatory light and method of application. Light restriction programs involving the application of one or more of the above factors have been studied by Asmundson and Moses (1950), Marr et al. (1956), Harper and Parker (1957), Ogasawara et al. (1962), McCartney et al. (1961), Leighton et al. (1961a, b), Wilson et al. (1962), and Marsden and Lucas (1964). On the …