World Science and Research PublicationsGlobal Journal of Animal Scientific Research2345-43771120131202Effect of Month of Production on Reproductive Traits of Barred Plymouth Rock Parent Stock in the Humid Tropics4652ENSimeonO.OlawumiAnimal Breeding and Genetics Unit, Department of Animal Production and Health Sciences, Ekiti State University, P. M. B. 5363, Ado-Ekiti. olawumisimeon@yahoo.com2014012820140128Seasonal effects on reproductive performance of birds had been overblown in previous study with little or no mentioning of influence of individual month that comprised the season. It is imperative to understand the impact of each month in a season or year on the reproductive performance of birds for effective planning and productive management decisions. The main objective of this study, therefore, was to determine the effect of individual month of production on reproductive traits of Barred Plymouth Rock layer breeder hens. Data used for this study were collected from farm records kept between 2002 and 2005. Analyzed data showed that month of production significantly affected all the reproductive traits, and that coldest months, that is, June-September favored high egg production, fertility and hatchability rates, while hottest months, that is, October-May impacted negatively on birds’ performance. In addition, mortality rate was low during coldest months but highest in the hottest periods. The month of July recorded the highest (peak) production levels for all the traits, while the lowest was observed in November. This study revealed that prevailing environmental temperature in individual month determines the productivity level of breeder hens, and hence the profit margin of the stockholders. Therefore, concerted efforts should be made towards massive production of fertile eggs during the aforementioned cool and favorable months in order to meet the increasing demand for day-old chicks by poultry farmers. Possible intervention to increase broiler chickens production is that producers should plan their re-stocking in such a way that the birds will commence egg laying at the onset of cold months in order to maximize the positive influence of these months on performance of breeder birds.