Sensitivity of Embryos from Duck, Goose, Herring Gull, and Various Chicken Breeds to 3,3′,4,4′-Tetrachlorobiphenyl

Yolks in embryonated eggs from duck, goose, herring gull, and various breeds of chicken were injected with 3,3',4,4'-tetrachlorobiphenyl (TCB). Hens' eggs were injected after 4 days of incubation and eggs from the other species were injected after 5 days of incubation. All breeds of chicken tested were very sensitive to TCB. At a dose of 20 micrograms/kg egg the death rate in chick embryos ranged from 70 to 100% at the end of the experiment by Day 18 of incubation. Liver lesions, hydropericardium, subcutaneous edema, shortened beak, and microphthalmia were found in both dead and living TCB-treated chick embryos. Embryos of the other species tested were considerably less sensitive than chick embryos to TCB. The highest dose administered to these species was 5,000 micrograms/kg egg for ducks and 1,000 micrograms/kg egg for geese and herring gulls. These doses did not affect the viability of the embryos and caused no gross abnormalities.