Feeding crushed eggshells vs oyster shells

[Mother Clucker17]

Which do you feed to your chickens? I feed mine both but no matter what they always charge straight for the eggshells but when I throw out the oyster shells they pick up a couple but they always leave them behind. I don't get it. Why do they like the eggshells so much more? Is one more calcium-dense than the other?

 

[ChickenCanoe]

Which do you feed to your chickens? I feed mine both but no matter what they always charge straight for the eggshells but when I throw out the oyster shells they pick up a couple but they always leave them behind. I don't get it. Why do they like the eggshells so much more? Is one more calcium-dense than the other?

Both egg shells and oyster shells are primarily calcium carbonate so are basically identical.
Large particle oyster shell is important for lAYING HENS.
The egg shells may contain remnants of the albumen which has protein, vitamins and minerals so that may cause them to go there first.
What concerns me is that you mention throwing them on the ground. Those offerings should be in their own container free choice. Those producing egg shells need to choose when to consume calcium.

 

[IamRainey]

My experience exactly, Mother Clucker! Can't keep up with their appetite for eggshells!

They do also consume the oyster shell though. I don't see them go for it as they do the eggshell fragments but I'm always having to refill their oyster shell cup.

I've found that there are two kinds of oyster shell. The first stuff I got was (from Manna, I believe) small, hard, very white stone-like crumbles. That stuff was expensive -- and only available in small bags I was constantly replacing -- so I went looking for something more affordable. Now I've got a 50# bag of something more porous, grey, flake-like and far closer in appearance to an actual oyster shell.

They go through the cheaper flakey stuff much faster but I suspect that may have something to do with it being more soluble and going through their systems faster.

 

[IamRainey]

The egg shells may contain remnants of the albumen which has protein, vitamins and minerals so that may cause them to go there first.

Can't speak for Mother Clucker but I wash my shells with running hot water, microwave them then lightly crush them. At that point, they're clean and brittle. My girls aren't going for them for albumen.

I've been told the oyster shell is important for them because it breaks down slower in their bodies and provides a more constant level calcium for new shell production. All I can say is what my hens go for, that they have a choice of both and that they produce sturdy shells.

 

[Cluckingitup]

Mine also go for eggshells faster than oyster shell. It may be that I only bring out after I have a small bowl full so they may think its a treat. I don't rinse mine but I do pop in microwave for 20-30 seconds then crush them. I have 6 laying hens, they do not seem go through OS like Iamrainey, and it is available all the time, since I feed all flock. I did think I would go through more OS than I am. My eggs seem fine so I guess they are getting what they need.

 

[Mother Clucker17]

What concerns me is that you mention throwing them on the ground. Those offerings should be in their own container free choice. Those producing egg shells need to choose when to consume calcium.

I don't throw a big pile on the ground or anything like that. Everyday a throw a handful of OS and ES on a rock in the ground so they can pick up what they need. There is usually some left behind. Also I should of been more specific about where exactly they are on the ground lol.

 

[Mother Clucker17]

Can't speak for Mother Clucker but I wash my shells with running hot water, microwave them then lightly crush them. At that point, they're clean and brittle. My girls aren't going for them for albumen.

I've been told the oyster shell is important for them because it breaks down slower in their bodies and provides a more constant level calcium for new shell production. All I can say is what my hens go for, that they have a choice of both and that they produce sturdy shells.

I just put the shells in a bowl until it gets full, then I put them on a tray in a toaster over at 250 degrees Fahrenheit. I never really washed them or anything so I imagine all parts of the eggshell are "intact". I dry them until they are hard, dry, and brittle. That makes sense about the oyster shells thought as they are bigger and thicker than the eggshells when you look at them side by side.

 

[aart]

I mix the ES and OS in a separate feeder.
They do seem to like the ES even tho I rinse, dry (tho do not heat) and crush them pretty finely.

 

[oldhenlikesdogs]

I read an article that says eggshells are digested fairly quickly, and oyster shells stay in the body much longer and hens have available calcium for much longer in their bodies. Which is important especially over night as it's when most eggs are being produced by the hen.

They do seem to prefer eggshells to oyster shells. My guess is because there's probably bits of protein attached to those eggshells from the insides of the eggs which makes them tastier.

 

[pibb]

My experience is as oldhenlikesdogs says. They seem to like the eggshells better and will gobble them up when I put them out. I can see little flakes of eggshells in the poop not real long after they consume them. The oyster shell seems to last longer in their system and it looks like little polished white stones when they come out. I've assumed they are using the oyster shell as grit until they file down small enough to pass out whereas the eggshell just passes through.