ABSTRACT This study was conducted to calculate the heat requirements of Hy-line W-36 and Hy-line W-98 layer chicks placed on different dates, and to select one of these strains based on heat requirements and egg prices. An environmentally-controlled, mechanically-ventilated, and fan and pad-cooled house with a capacity of 94,500 chicks was designed. Based on the identification of September as the month with the highest egg prices, placement dates were selected (16th of March, 1st of April, 16th of April, 23rd of April and 1st of May) to coincide with economic egg weight in that month. The heat requirements for a rearing period of 35days of both evaluated strains starting on the above-mentioned dates were calculated using heat and moisture balance method... |