Carbon Monoxide and Avian Embryogenesis

Abstract

Embryonated chicken eggs were exposed continuously So various carbon monoxide concentrations during the first 18 incubation days. Hatchability and viability were inversely related to CO concentrations. The eighth to 14th incubation days constituted the critical period, beginning with the 425-ppm level. Macroscopic observations on experimental embryos revealed “compensatory hypertrophy” of extra-embryonic blood vessels, and amnionic vesiculation. Elevated serum lactic dehydrogenase and increased serum albumin levels occurred in embryos exposed to 425 ppm CO. A “quasi-taliped” condition appeared in hatched chicks exposed to 650 ppm. Carboxyhemoglobin levels of controls were uniform, averaging 1.50% (SD ± 0.80) from the tenth to 16th incubation day: levels of embryos exposed to 425 ppm CO averaged 6.15% (SD ± 1.18) from days 10 to 14 with abrupt increase to a mean 14.85% (SD ± 2.65) on days 15 to 16.