Poultry Science · 1954 · 10 citations · 2 references
AgricultureAnimal SciencesZoologyEgg ScienceOrnithologyPoultry ReproductionEgg BiologyEgg ProductionPullet RearingReproductive PerformanceReproductive SeasonalitySeasonal ReproductionDay Length ResponseEgg Production SeasonalityEgg Production Under Lighting RegimesEgg Size DeterminationField ObservationsIllumination LevelsLength Of Day VariationsOutdoor Illumination
HATCHING egg producers using supplemental hatches of fall pullets to provide a year around uniform supply of hatching eggs have found that small egg size (under 22 ounces per dozen) is a problem with out-of-season hatched birds. Pullets hatched during October, November and December tend to lay small eggs over a longer period of time than pullets hatched in the spring of the year, and therefore produce a lower ratio of saleable hatching eggs during their year of production. These field observations have been confirmed by research reports pertaining to this problem. Jeffrey and Platt (1941) found that on a yearly basis their April hatched White Leghorn pullets produced 55 percent large eggs; January hatched, 47 percent; November hatched, 43 percent; June hatched, 42 percent; and September hatched, 38 percent. Callenbach et al. (1944) studied the relative effects of normal day length, and continuous 24-hour per day illumination as supplied …
2