Serum corticosterone concentrations in developing shell-less and shelled turkey embryos.

1. Turkey embryos grown in shell-less culture (EO) display normal development to day 14 of incubation, after which growth rate is reduced and mortality increases, compared to age-matched in ovo (IO) embryos (Richards 1982. Long term shell-less culture of turkey embryos. Poultry Sci. 61, 2089-2096). 2. In this study serum corticosterone concentrations were monitored in normally incubated embryos and embryos maintained in shell-less culture. 3. On days 14 and 16 of incubation, corticosterone levels were greater (P less than 0.05) in EO than IO embryos, whereas during the later stages corticosterone increased dramatically in the shelled embryos, and remained relatively constant in the EO embryos. 4. EO embryos do not exhibit a pattern of adrenal hormonal secretion that would indicated a stressful condition. 5. The absence of a normal increase in corticosterone in shell-less embryos may contribute to the abnormal embryological development in the later stages of incubation.