The Influence of Season and the Age of Layers on Egg Weight, Shape Index, Albumen Quality and Shell Thickness

IN RECENT years an increasing number of poultrymen have been keeping layers for a second year of production. While adequate information is available on changes in egg quality during the pullet year, experimental evidence on the effect of age on egg quality during the second year of production is, with the exception of egg weight, relatively limited. Romanoff and Romanoff (1949) reviewed the literature on the changes in egg weight as the age of layers increases. They state that in spring hatched pullets egg weight increases from October to February or March, then declines somewhat until midsummer, but subsequently increases until it approximates that of two year old hens in October or November. According to these authors two year old hens lay their largest eggs in December or January and their smallest eggs in May, June and July. Benjamin (1920) in an experiment with Single Comb White Leghorns, found no …