Examining the Effects of Prestorage Incubation of Turkey Breeder Eggs on Embryonic Developmentand Hatchability of Eggs Stored for Four or Fourteen Days

Abstract

Thirty-six hundred British United Turkey hatching eggs were used in two separate 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 hatchability of eggs stored (17 C) for 14 versus 4 d. The development of the embryos (n = 30) was staged before and after exposing eggs to the various PRESI treatments. Embryonic development was also established after storage to ascertain whether embryonic development was occurring during storage. The remaining eggs in each trial were split into three groups (n = 500) and incubated for 28 d to examine embryonic mortality and hatchability. No changes were observed in embryonic development due to egg storage. Embryos were significantly more developed as the number of PRESI h increased; therefore, embryos from different PRESI treatments were placed in storage at different stages of development. Early mortality (1 to 7 d of incubation), mortality at internal and external pipping, and hatchability of fertile eggs were significantly reduced in eggs stored for 14 versus 4 d. The various PRESI treatments did not significantly affect the mortality or hatchability of eggs stored for 4 d. However, the hatchability of eggs incubated prior to storage for 12 h and then stored for 14 d was restored to the levels reported for eggs subjected to the treatment that represents the industry norm (0 h of PRESI and 4 d storage). These results indicate that embryos of eggs stored for 14 d, which have developmentally advanced to the stage of complete hypoblast formation (PRESI for 12 h), have a survival advantage over eggs stored for 14 d that have not been subjected to any PRESI.