Use of Avian Embryos
Avian embryos develop in ovo rather than in utero as in mammals, and therefore their experimental use is independent of maternal influence. There are two important final events in embryonal development that are necessary for sustainment of life outside the shell. The organ maturing last in the avian embryo is the lungs. They must be functional to sustain life outside the shell. The yolk sac, which is the source of nutrients for the developing embryo, is withdrawn into the body cavity at the same time the lungs become functional. These two events occur at approximately 48 hours prior to hatching. However, some embryos hatch a few hours earlier than others placed in an incubator at the same time.
OSU Policy
The IACUC will review all protocols which utilize avian embryos that are within three days of the expected hatch time for the species (i.e. 18 days incubation for chickens and 25 days for turkeys).
PHS Policy
Applicable to proposed activities that involve
live vertebrate animals. While embryonal stages of avian species
develop vertebrae at a stage in their development prior to hatching,
OLAW (Office of Laboratory Animal Welfare) has interpreted "live
vertebrate animal" to apply to avians (e.g., chick embryos)
only after hatching.
