Temperature as one of the most important single physical factors determining or influencing embryo development and hatchability is reviewed and possible temperature manipulations are discussed as a management tool.
Pre-incubation egg holding temperature is reviewed as a factor acting on variability in developmental stage at oviposition. A mathematical approach for determining the temperature threshold or physiological zero for embryonic development is outlined. Temperature requirements during incubation are discussed, taking into account the ultimate aims and objectives of the incubation process, i.e. hatchability and chick quality for survival, growth and reproduction, challenging at the same time the idea that the best hatchability is synonymous with the highest chick quality.
Factors affecting limits of variation in incubation temperature, with particular reference to strain or line differences, are discussed.