Question about egg weight

[ThatLittleChick]

Hi, we did a science project in class where we each chose one fertilized egg and got to follow its development. We candled and weighed it about 1-2 times a week and I noticed that about a week after we put the eggs into the incubator, mine started to lose weight. It started off at 36,7 grams and at the final weighing it weighed 30,3 grams. I was wondering if you guys could explain why it lost weight? Also, mine didn't hatch on day 21 and I wonder if you might know why it didn't?

Thanks in advance!

 

[ChickenCanoe]

Welcome.

The eggs are supposed to lose weight but yours may have lost too much. The moisture in the egg evaporates through the pores which, even though there's often an embryo developing in there, causes the weight loss.
It should be about 0.65% of the weight each day.

Why didn't it hatch? About 100 reasons.

http://ufdc.ufl.edu/UF00008570/00001/6j

 

[ThatLittleChick]

Welcome.

The eggs are supposed to lose weight but yours may have lost too much. The moisture in the egg evaporates through the pores which, even though there's often an embryo developing in there, causes the weight loss.
It should be about 0.65% of the weight each day.

Why didn't it hatch? About 100 reasons.

http://ufdc.ufl.edu/UF00008570/00001/6j

Thank you so much for the help! The ones that did hatch were the most adorable little fluffballs I've ever seen :')