Question: What causes egg shells to become paper thin?

[Tootie123]

I have 10 hens whom up to this time have been laying fine. Recently I have noticed that I am getting some eggs every now and then with paper thin shells or even partly broken....
The girls have been doing fine. They free range just about every day. I feed them a combination of laying mash, scratch feed and every once in awhile I throw in some gravel from the feed store that I keep on hand. In their water I put a little cider vinegar occasionally.
Does the heat effect their laying? Noticed they haven't been laying as many eggs as they
normally do either. We have gone from 75-80 degree days to days over 90 degrees.
Atlanta can be quite humid and hot in the summer time that is why I let them out just about
every day because of the heat that builds up inside the coop even though there are air vents.
Just curious as to why the thin shells.....hum mm? Haven't experienced this before.
Any ideas?

 

[Habibs Hens]

egg laying uses a lot of calcium

you need to supplement calcium for all that they loose in laying

if they don't have calcium they cant spare it for the eggs

so they are thin

add oyster shell to their diet

 

[Tootie123]

Thanks, will buy some oyster shells the next time I get into the feed store.
Also have read where you can break up their egg shells and feed them back to them
and that will help with the calcium. Is that a good idea? Don't always have egg shells
to feed them but when I do I can.

 

[Habibs Hens]

Thanks, will buy some oyster shells the next time I get into the feed store.
Also have read where you can break up their egg shells and feed them back to them
and that will help with the calcium. Is that a good idea? Don't always have egg shells
to feed them but when I do I can.

Its been said that it can be done

personally i wouldn't as it could possibly cause egg eating when they realise they are easting the shells