Use of hatch date for broiler breeder production planning

Data on 109 batches of broiler breeders belonging to six strains and bred i n conventional sheds were analyzed to determine the possible influence of n atural day length cycle phase on age at start of laying, at sexual maturity , and at peak egg production. The dependence of these variables on date of hatching was characterized by polynomial regression analysis. The resulting equations constitute simple, novel empirical models that are in keeping wi th current theory on the effects of photoperiod on sexual maturation, and s hould facilitate production planning in broiler breeder farms.