I know the chickens don't need a roo to lay. Why is that? I've always wanted to know and explain it to some people at my school who say "how can a hen lay if she doesn't have a rooster?" or "no no hens need roosters to lay eggs" you know all the same jibber jabber.
Just like a woman - the egg (ovum) is released from the ovary and travels through the fallopian tubes. In a woman, if it's fertilized, it implants in the uterus. If not, the egg continues and is flushed out monthly during the woman's period, along with the blood-lining of the uterus. In a chicken, a yolk and whites and shell are built around it. If it's fertilized and kept warm, etc, a chick grows inside until it's ready to hatch; otherwise, the egg comes out anyways, just not fertilized. In a woman, it's about a 28 day cycle. In a chicken, it's about a 25 hour cycle. Does that help?
Most of the time spent "building" an egg to be laid is spent in creating the shell, nearly 19 of the 25 or 26 hours. Because of that, if something goes wrong in the laying process, it's generally in the part creating the shell. The next to the last thing is color added to the shell, and then finally a protective covering called the "bloom."
this is good too.......... http://www.thepoultrysite.com/publications/1/egg-quality-handbook/2/formation-of-the-egg
BTW the reason we don't think of women as "laying eggs" although we do ovulate an egg (called an "ovum" -which is just latin for egg) every month is that mammals keep the fertilized ovum in the uterus to develop until viable, whereas chickens have a mechanism for creating a kind of temporary life support pod complete with all the nutrients necessary for that fertilized ovum to develop into a viable chick. That whole "temporary life support pod" is what we call an egg, shell and all, when we talk about chickens. In chickens, the whole "life-support pod" is created for every ovum, fertilized or not. Simpler plumbing that way, I guess. In humans, the equivalent life-support system (placenta etc) doesn't fully develop unless the egg(ovum) is fertilized. Otherwise, it gets flushed out every month along with the unfertilized egg.
Quote:Yep, that's my response when I get that question. I just say, "Same as a human female, a hen regularly ovulates with or without fertilization...now, if you want babies from those eggs, well..." And then a look of recognition happens, "Ahhh!"
