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Name: Eric E
Status: student
Age: 18
Location: N/A
Country: N/A
Date: 2002


Question:
This might sound a little silly, but it's been nagging on my mind. Let me start by asking, does fertilization have to take place every time a bird lays an egg/a clutch of eggs? Does this mean that all eggs laid have the potential to be viable? This is actually related to my main question about commercial chicken egg production. If the answer to the first question is "yes", then how do they manage tocontinually fertilize so many hens to keep up with high production rates? Does this also mean that the eggs we get at the supermarket (for humanconsumption) are actually viable? I am confused because I think I have read somewhere that eggs for human consumptions are actually unfertilized.


Replies:
Eric,

1. No, fertilization does not have to take place every time a bird lays an egg or clutch of eggs. If you had a pet bird, for example a cockatiel, you would note that the female will routinely lay eggs even if alone in a cage (i.e. without a male present). The eggs will be infertile, that is, they will not be able to produce young. This will quickly be discovered as the eggs will begin to smell after a couple of days. (If the egg were developing into a young bird it would remain "fresh" smelling).

2. No, even as in humans, all eggs do not have the potential to be viable if they are not fertilized. The eggs themselves are alive but will die as do all cells if they are not fertilized. (The resulting young is not immortal either).

I think the above answers should satisfy your remaining questions.

Thanks for using NEWTON!

Ric Rupnik


Think of it this way. Human females ovulate each month. If there is sperm to fertilize them they are viable. If not, they are expelled from the body. Chickens are fertilized internally and then the shell forms around the embryo. But if fertilization does not take place the egg is laid without being fertilized. So some eggs that are laid are viable and some are not. I believe that there is a certain amount of mating that is necessary to keep the hens laying, but I am not sure how much. You cannot always tell from outside whether an egg is viable except under a very bright light. This is called "candling". An embryo would appear as a dark spot in the egg. These are removed before shipping.

vanhoeck


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