Main Problems Rearing, Incubation 66.7% of early to mid term embryonic death (28 days) was due to bacterial infection (mainly E. coli). In Egypt, malnutrition and poor hygiene are the main cause (E. coli, Pseudomonas aeruginosn and Salmonella). 33% of the late death (≥ 28 days) was due to embryo malposition. 63% of late embryonic death was due to bacterial & fungi infections, shell quality (porosity, shell thickness, floating air cell) and extreme egg weight.