Vandenberghe Cunin, Nathalie CharlotteCeular Villacé, Ángel LuisMoreno, A.2021-01-212021-01-211999Poultry Science, Volume 78, Issue 4, 1 April 1999, Pages 501-5040032-5791http://hdl.handle.net/10347/24261Data on 109 batches of broiler breeders belonging to six strains and bred in conventional sheds were analyzed to determine the possible influence of natural 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 with current theory on the effects of photoperiod on sexual maturation, and should facilitate production planning in broiler breeder farmsengCopyright © 1999 Poultry Science Association Inc. Published by Elsevier Inc. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0) (https://creativecommons.org/licenses/by-nc-nd/4.0/)Attribution-NonCommercial-NoDerivatives 4.0 Internacionalhttp://creativecommons.org/licenses/by-nc-nd/4.0/Broiler breederProductionStart of layingSexual maturityPeak egg productionjournal article10.1093/ps/78.4.501open access