BACKGROUND

All use of vertebrate animals in research, teaching and testing is regulated by the Institutional Animal Care and Use Committee (IACUC). 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 two thirds through embryonic development can experience pain. If avian embryos hatch, intentionally or unintentionally, they are live vertebrate animals and thus regulated by the IACUC. Consequently, the Wayne State University IACUC has adopted the following guidelines. Chick embryos, which hatch in approximately 21 days, are considered the model species. If other avian species are used, then the guidelines should be adjusted based on relative time to hatching.

IACUC Policy

1. Research involving avian embryos that will be sacrificed prior to three days before hatching does not require IACUC review, as these are not considered to be live vertebrate animals. However, the IACUC must be informed of these studies via the form 'IACUC Notice for Use of Avian Embryos." The IACUC does require submission of a complete animal protocol for projects utilizing pre-hatched avian embryos or those utilizing eggs on or after embryonic day 18 (E18). 

2. Chick embryos younger than embryonic day 16 (E16) are assumed to be unable to experience pain. It is recommended that E15 or younger embryos be euthanized by hypothermia, typically by placing the eggs in a -20°C freezer.

3. Embryos E16 and older must be euthanized by humane methods such as C0₂, anesthetic overdose, or decapitation. It should be noted that embryos are resistant to C0₂. If this method is chosen, the embryos must be exposed to 90% C02 for at least 20 min. CO₂ must be delivered from a regulated gas tank. A physical secondary method of euthanasia must be used when euthanizing with CO₂ or anesthetic overdose.

4. The IACUC recognizes that inadvertent hatching may occur. Investigators are asked to describe their methods for humane euthanasia of hatchlings.

Form for IACUC Notice for Use of Avian Embryos

Approved: March 23, 2022