The effects of eggshell porosity on blood-gas and acid-base status of domestic fowl embryos within eggs of the same weight.

Eggshell porosity affects the metabolism and growth of the developing embryo and is likely, therefore, to influence blood-gas and acid-base status. PO2 in the airspace and in blood from the allantoic vein, PCO2 in the airspace and in blood from the allantoic artery and allantoic vein, and pH of blood from the allantoic artery and vein are all affected by shell porosity. Low porosity eggshells result in an increased retention of carbon dioxide within the egg, in partial compensation for which an increase in the level of bicarbonate in the blood is predicted. It is concluded that some of the wide variation in blood physiology data between eggs at the same stage of incubation, which has been recorded in the scientific literature, is the result of variation in shell porosity between eggs.