Pre-Incubation Warming of Chicken Eggs

WARMING of hatching eggs prior to the regular incubation period resulted in improvement in the hatchability of chicken and turkey eggs (Kosin, 1956; Becker and Bearse, 1958). Milby and Sherwood (1960) showed that pre-incubation warming only increased hatchability of turkey eggs produced from hens whose hatchabilities were below the average of the population (Milby and Sherwood, 1960). The usual warming procedure is to subject eggs to a period of five hours at 99.5°F. the day after they are laid, after which time the eggs are returned to the egg holding room for the remainder of the storage period. The question arises as to whether greater benefit could be obtained if warming is applied, instead of on the day after lay, somewhat near the middle of the storage period. Or, the five-hour warming might be given in the form of two or more doses with approximately equal intervals between applications. In …