Turkey Egg Weight Losses and Embryonic Mortality During Incubation ,

Shell conductances (mg H2 O·day–1 ·torr–1) of fertile and infertile turkey eggs did not differ significantly after days 7, 14, 21, or 25 of incubation. Furthermore, conductances of eggs that subsequently hatched, contained early dead embryos, or contained late dead embryos did not differ significantly before 7 days of incubation. For the incubation periods 7 to 14, 14 to 21, and 21 to 25 days, eggs with embryos dying late in the course of incubation had significantly lower conductances than eggs with embryos that subsequently hatched or eggs that had died early during development. Fertile and infertile eggs did not differ significantly in egg weight, surface area, percentage of initial egg mass lost during incubation, or amount of water vapor lost per square centimeter of surface area. Similarly, no significant differences were observed between eggs with embryos that hatched normally and eggs with embryos dying early in incubation for any of the aforementioned parameters, but eggs with embryos dying late in incubation had significantly lower percentage of initial egg mass lost and lower amounts of water vapor lost per square centimeter of surface area. Eggs exhibiting late embryonic mortality had the same egg weights and surface areas as the other hatchability groups. It was concluded that gaseous conductance of some turkey eggshells is insufficient to meet embryonic demands late in incubation.