Examining the effects of prestorage incubation of turkey breeder eggs on embryonic development and hatchability of eggs stored for four or fourteen days

Thirty-six hundred British United Turkey hatching eggs were used in two sep arate trials to test whether prestorage incubation (PRESI) treatments of 0, 6, and 12 h (Trial 1) or 0, 7, and 14 h (Trial 2) could improve the hatcha bility of eggs stored (17 C) for 14 versus 4 d. The development of the embr yos (n = 30) was staged before and after exposing eggs to the various PRESI treatments. Embryonic development was also established after storage to as certain whether embryonic development was occurring during storage. The rem aining eggs in each trial were split into three groups (n = 500) and incuba ted for 28 d to examine embryonic mortality and hatchability. No changes we re observed in embryonic development due to egg storage. Embryos were signi ficantly more developed as the number of PRESI h increased; therefore, embr yos from different PRESI treatments were placed in storage at different sta ges of development. Early mortality (1 to 7 d of incubation), mortality at internal and external pipping, and hatchability of fertile eggs were signif icantly reduced in eggs stored for 14 versus 4 d. The various PRESI treatme nts did not significantly affect the mortality or hatchability of eggs stor ed for 4 d. However, the hatchability of eggs incubated prior to storage fo r 12 h and then stored for 14 d was restored to the levels reported for egg s subjected to the treatment that represents the industry norm (0 h of PRES I and 4 d storage). These results indicate that embryos of eggs stored for 14 d, which have developmentally advanced to the stage of complete hypoblas t formation (PRESI for 12 h), have a survival advantage over eggs stored fo r 14 d that have not been subjected to any PRESI.