In this book you will read every thing about the harmful effects of heat stress on laying hens' health and production from different aspects and how to cope with these effects. The present study was carried out at the Laying Hens Research Farm, Department of Poultry, Faculty of Agriculture, Zagazig University, Zagazig, Egypt, during the period from July to September 2008. A total number of 243 forty two weeks of age, Bovans laying hens were randomly distributed into twenty seven treatment groups to investigate the effect of dietary vitamin A (0, 8000 and 16000 IU/ kg diet), vitamin E (0, 250...