Someone asked this recently...here is the information I gave them
Is it Ag lime or Hydrated Lime? Hydrated will kill them...
here is the information from the Dept. of Agriculture
There are two different kinds of lime.
Hydrated lime, slake lime, or "burn lime"- This is pure white. Hydrated lime is very caustic, so the bag will have a warning on it. This is the kind of lime you use for white wash . This lime will burn you and your livestock. Do not use it on the floor. Do not breath it.
Agricultural lime, "ag lime", "garden lime", "barn lime" or dolomite- This lime is gray and can be used to spread on the floor of your barn. This is safe for you and your livestock. It will not burn.
In the past we spread Ag. lime on our barn floor because it provides an antibacterial quality, dries out and "sweetens" the floor , and also it makes it easier to clean, for some people.
If you just ask for lime at your feed store, they will probably give you hydrated lime. If you say it's for the barn floor they will still probably give you hydrated. Please be safe, get the "Ag" lime .