Embryonated Avian Eggs in Research and Teaching




Research and teaching activities using embryonated avian eggs require IACUC oversight under certain circumstances, and always require humane euthanasia regardless of stage of development.


Avian embryos are not considered live animals by U.S. regulatory agencies. Nonetheless, there is a consensus in the scientific community that avian embryos greater than approximately two thirds through embryonic development may be sufficiently developed to experience pain. Additionally, OLAW expects Assured institutions to have policies and procedures in place that address the care or euthanasia of animals that hatch unexpectedly. If avian embryos hatch, intentionally or unintentionally, they are live vertebrate animals and thus require oversight by the IACUC. Consequently, IACUC has adopted the following guidelines that apply to all avian species. Domestic chicken embryos, which hatch in approximately 21 days, are considered the model species. If other avian species are used, the guidelines should be adjusted based on relative time to hatch for that species.


The IACUC requires submission of a complete animal use protocol for projects utilizing pre-hatched avian embryos (for example, those utilizing chicken eggs on or after embryonic day 16 (E16)), and any use of embryonated eggs that will subsequently be allowed to hatch.

IACUC protocols that utilize either egg-laying adult animals, including breeding to obtain embryos, or eggs on or after E16, must describe:

  • the stage of incubation during which live embryonated eggs will be used or disposed of;
  • the method of disposition of embryonated eggs consistent with the AVMA Guidelines on Euthanasia;
  • the steps that will be taken in the event that an egg, at any stage of development, inadvertently hatches.


Research involving avian embryos that will be euthanized prior to completing 75% of the total expected incubation period does not require IACUC review. For example, for domestic chickens with a 21-day incubation period, research ending in euthanasia on or before day 15 of incubation (E15) would not require an animal use protocol.

Note: Eggs being euthanized prior to completing 75% of incubation, including those used in wildlife field studies, must be handled as described in the AVMA Guidelines on Euthanasia.


Approved Date

Revised Date