oyster shell/limestone/egg shells as calcium supplements

[livin-green]

I have been offering oyster shell to my laying hens since they began laying about two months ago. I have been buying the Manna Pro crushed oyster shell which is about $5.99/5lb bag at the local Co-op.

A few days ago I visited a feed store with my sister and bought what I thought was oyster shell in a 50lb bag for $7.99--they said it was oyster shell. It's called Tuff Shell. So, I get it home & start reading the bag--this is what it says:

Tuff Shell: Feed Grade Calcium (front)
The back reads: Calcitic Limestone
Typical Dry Weight Analysis CA (Calcium) 38%

It also has a warning:
[This product contains small amounts of crystalline silica, a common mineral found in natural sands and stones. Excessive inhalation of respirable silica dust may cause cancer or lung disease. Avoid breathing dust. Wear approved respirator in dusty areas.]

Now, this just doesn't sound good to me. I'm even confused why I'm feeding them limestone....?? Seems like that is just grit--it looks like grit, not oyster shell...which is what they said it was. Not. Do any of you guys use this?

Additionally, I supplemented them with crushed egg shells yesterday. But, I'm not sure how much to provide or how to prepare it. If I do this, I've heard and read that you should bake the shells--is that really necessary? Any help here would be appreciated!

 

[speckledhen]

It isn't grit, it's limestone calcium. I am using it now. Usually, I'd get oyster shell for $7/50# bag, but its very dusty and I have to sift the dust out of it. It takes many crushed eggshells to equal the calcium in oyster shell. I dont find the limestone all that dusty and it is TuffShell.

 

[livin-green]

So, you aren't concerned with the warning? I'm chicken (no pun intended) that I could end up with respiratory problems. Or the chickens could have problems--no?

The Mann Pro that I've been buying wasn't too bad--is the dust from it a problem as well? I didn't notice a warning on it, but I don't have an old bag to look at now.

I get the paranoia from my mom....LOL!

 

[speckledhen]

That warning is on my oyster shell, too. Nope, not worried.

 

[livin-green]

Aahh! Well, I guess I just didn't catch it before.

Just curious, which do you think is better? Oyster shell or the limestone calcium. I also feed them yogurt pretty regularly, if that matters, and will probably give them any egg shells that we have (I use those in my potting soil as well).

 

[greyfields]

The ammounts of this they will actually ingest is so small that the warning is to humans, not to your birds. If you were mixing up several tons of the stuff, you'd want to take precauctions.

And 50# bags are the only way to go. I get straight oyster shell here, but I'm on the coast. I'm sure it varies regionally.