Jail Break
Posted by Mary Vogas on October 9, 2003
Q: In the article on Jail Break, April 2003, it stated that the air in the air chamber is high in CO2. Why high in CO2?
A: I rechecked 2 sources on this question and although both mentioned the high level of CO2 in the airchamber shortly before hatching - neither explained why. I'm going out on a limb and would surmise that this is a result of 2 things -the chick's metabolism and the structure of CO2. Since the growing chick is using O2 and giving off CO2 as a waste product, some of this CO2 may escape the umbilical blood system and pass through the membrane surrounding the chick and leak into the air chamber where it is "trapped". CO2 is a much heavier/larger molecule than O2 and probably displaces or prevents entry of any O2 that might enter the air chamber via the eggshell pores and thus builds up over time. Even though the almost-ready-to-hatch chick breaks into the air chamber before it pips through the shell, it continues to obtain all or most of its O2 needs from its umbilical blood supply and not its lungs. Once the chick does break through the shell, however, it can begin breathing normally from the surrounding air.
If we have any poultry experts reading this question/answer, would love to hear from you on this.
John Wiessinger ( October 10, 2003)