Effect of the pre-incubation storage period of hatching eggs on the hatchability and post-hatching growth of local chickens under tropical conditions.

In order to study the effect of the storage period, 2400 hatching eggs from hens in the Tanzanian coastal region were stored for 0 to 15 days under room conditions of temperature and humidity. On the 16th day of a collection period with daily additions, the incubation of 50 eggs each was started. At hatching time, the number of healthy chicks hatched from each storage period treatment was counted. Also studied was the growth of the hatched chicks for the first three weeks of their life. A highly significant negative correlation (-0.98) was observed between the pre-incubation storage period and the hatchability of eggs. The regression coefficient was found to be -5.3. This means that hatchability declined by an average of 5.3% for each day the eggs had been stored. Prolonged storage of hatching eggs also affected the post-hatching growth performance of these chicks. The adverse effect disappeared, however, with increasing age of the chicks. It is recommended that hatching eggs should not be stored under ordinary room conditions in the tropics for more than 7 days prior to hatching.