Expert: Chrys Meatyard - 10/10/2006

Question
I already saw, with a light, what's inside the egg, there's a dark part in the center of the egg, and 2 lighter parts on the sides of the egg (...) i read that this parts are filled with air and that they'll grow with the time (...)i can't see veins, but as far as i know duck eggs are thicker than normal eggs, so it's too hard to see what's in the inside and it is also very hard to incubate them because they need higher temperatures! BUT, with your help, i saw, again, with a light, the interior of a normal infertilized chicken egg from the fridge, and all the egg is the same, excepting the little air part (...) it looked very different from my duck egg! (...) so, according to this characteristics, do you think ther's a possibility of hatching?!
Another thing! what happens if you eat a fertilize egg? is that possible? i mean, if you don't know if a chiken egg is fertilized and you want to eat it (...)thanks again! =)

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Followup To

Question -
Hi! since you have experience in raising birds, maybe you can help me! (...) I have a duck (female) that right now has eggs, but i don't know if the eggs are fertilized! is there any way to know if an egg is fertlized? i mean, like a difference between a fertilized and a non fertilized egg? thank you!

Answer -
Hi, Doina.  Thanks for posting!

I don't know much about duck eggs, but I'm guessing they would be the same as any other avian eggs as far as determining whether they are fertile or not.

Do you know when the eggs were laid?  If so, about 10 days after they were laid, you can candle them.  Candling is the process of shining a light source through the eggs to see what you can see inside (if anything).  Use a pen light or flashlight and shine the light from the back side of the egg so you can see through the egg.  On the inside, an infertile egg would look like a chicken egg from your refrigerator (which are infertile).  A fertile egg (at about 10 days) will show a small spot (embryo) on the inside with red veins throughout the egg.  As a fertile egg grows older, the developing embryo will start to fill up the inside of the egg, i.e., the egg will start looking darker/deeper white on the outside.  On the inside, you will see a darkened area representing the developing embryo...this area will grow larger with time.

I would imagine the same holds true with ducks as with other aves in that a female bird can lay infertile eggs without mating with a male.  Therefore, if your female doesn't have a mate/hasn't mated, the eggs will not be fertile.  

Chrys

Answer
Hi again, Doina.

Below are 2 websites that can help you with your duck eggs:

http://www.duckeggs.com/hatching-eggs.html
http://www.metzerfarms.com/hatch.htm

I don't know if they will hatch...I don't have enough detailed information.  Also, if incubation was started then the eggs allowed to cool down too long, they won't develop and hatch.  You'd have to buy an incubator if you wanted to hatch these duck eggs manually.  This would take care of the higher temperature requirements.

I don't know of people who eat fertilized eggs (and I've traveled all over the world); I mean, what would be the point?  Normally, chicken eggs are pulled every day from under the chickens in a chicken coop, therefore, the chances of collecting a fertilized egg is slim (unless eggs are allowed to stay under the female for a week or longer).  Also, if a person opens a fertile egg, it's immediately apparent in most cases (unless a person just isn't paying attention).  If a person would eat a fertile egg by mistake (cooked hopefully), I wouldn't think it would be a health problem or anything...just sounds yucky!  Once or twice over the years I've opened a chicken egg I bought from the store to find it partially developed, however, I just threw it away.  

Good luck!

Chrys