Tell me I am not crazy -- that developing eggs do gain weight!!

[MissJenny]

I was telling my boyfriend about how I can tell chicks are developing in the eggs in my incubator because they are gaining weight -- and he laughed at me, like I'm some silly girl.

He says the egg can never weigh more than what it does when it is laid. That the material inside remains the same.

I say that's nuts -- that as the chick develops, as a maybe develops, it brings mass, density to the inside of the egg. I say that the skin and bones and heart and brains and blood of the chick have more weight than mere yolk and albumin.

Tell me I am right.

 

[madamwlf]

I think eggs are suppose to lose weight during incubation. The lost weight is from losing moisture in the egg.

 

[Moondance]

I've always thought they weighed more.... as half the time I can tell the unfertile eggs BEFORE I've candled, simply on how they feel in my hand.

 

[JulieNKC]

I'm pretty sure they lose weight during incubation, through evaporation through pores. Some people weigh their eggs, esp larger ones like geese to make sure they are developing on track.
They seem heavier to me before hatching though. Maybe because the chick is denser and the weight isn't as evenly distributed or something.

 

[Oregon Blues]

You aren't crazy. I think the eggs feel more solid as they get closer to hatching.

However, even though they feel more solid, they lose weight. Moisture evaporates from the egg.

The chick gains mass and builds bone, but all that material is already inside the egg when it is laid. The chick is just taking material that is already there and moving it into a different form. The chick builds bone but he is using calcium that is already stored in the egg for him.. He can't make calcium appear from nowhere with a magic chant. It's already inside the egg.