Prestorage incubation of long-term stored broiler breeder eggs: 1. Effects on hatchability

Two thousand eight hundred broiler breeder eggs were used to determine if prestorage incubation (PRESI) treatments of 0, 6, 12, or 18 h (at 37.5 C) could improve the hatchability of eggs stored (at 11.5 C) for 4 vs. 14 d. Embryonic development of 30 eggs was established after exposing the eggs to each PRESI treatment. The remaining eggs were cold-stored for 4 or 14 d and then incubated for 21 d. Unhatched eggs were broken open to determine fertility, and if fertile, stage of embryonic death was determined. Statistical significance was assessed at P < 0.05. Embryonic development significantly advanced (P = 0.00001) as the number of PRESI h increased. Therefore, embryos from each of the four PRESI treatments were placed into cold storage at different stages of development. Egg storage for 14 vs. 4 d significantly reduced the hatchability of all eggs set (58.4. and 88.2%, respectively). The PRESI treatments did not have a significant beneficial or detrimental effect on the hatchability of all eggs set for the eggs stored 4 d. However, in eggs stored for 14 d, PRESI for 6 h significantly improved hatchability of all eggs set (79.0%) when compared to eggs that were not PRESI (70.5%). The hatchability of all eggs set for eggs PRESI for 18 h and stored for 14 d was significantly reduced (9.1%) when compared to the other 14-d stored PRESI treatments. The results of this study provide evidence that embryos of eggs that have completed hypoblast formation (PRESI for 6 h) and are stored for 14 d have a survival advantage over embryos of 14-d stored eggs that have not been subjected to any PRESI treatments.