Gharib H, Desoky A, El-Menawey M, Abbas AO, Hendricks G, Mashaly M. The Role of Photoperiod and Melatonin on Alleviation of the Negative Impact of Heat Stress on Broilers. Int. J. Poult. Sci. 2008;7(8):749–756. doi:10.3923/ijps.2008.749.756