Considering all the moisture in the body, and the chickens body also, and considering the rear end of the chicken is use for dual purposes. how does an egg exit dry? And clean too? Or does it exit dry?
I am not sure about the clean question, but it comes out damp and it dries almost instantly. I have watched my girls lay.
The egg exits clean because of the way the system is put together. There are two different systems that meet at the vent. There is valving so the two don't contaminate each other. One discharges stuff that makes good fertilizer. The other discharges eggs. To keep the eggs clean, that part of the system actually exits the body and turns inside out when the egg is laid. If the part that turns inside out does not retract, you get what is called prolapse. The egg comes out with a wet coating on it called bloom. The bloom quickly dries and inhibits bacteria from entering the porous egg shell yet lets air pass through that porous shell so the developing chick can breathe. The bloom is not 100% totally effective in stopping the bacteria, but it works pretty well.
