Sorry, I will clarify:
my question is, is the suggestion to just dust some powdered or pelletized lime around on a dirt floor (or till it in), which is fine although it won't do much other than temporarily sanitize/deodorize?
or is the suggestion to make a floor out of like 6" of crushed limestone or screenings or limestone stonedust -- which, yes, are obviously chemically the same as whatcha buy in ag lime sacks but have rather different physical properties because of size/shape/depth. If this is what's being proposed -- a considerable depth of screenings or stonedust -- then IME it is going to make a mess as time goes by (with shavings mixing into it) unless it is compacted very hard.
Yes, limestone is of course predominantly CaC03. However there is a difference between dolomitic limestone (which also contains a bunch of dolomite, a high-magnesium mineral) versus calcitic limestone (which doesn't, and thus has very little magnesium in it). My impression is that low-magnesium calcium sources are generally preferred when supplementing Ca to chickens (this is
aside from the use of dolomitic limestone in commercial feeds, where its magnesium content is compensated for when the other ingredients are calculated/mixed). I am not sure how much of a difference it makes, but, it's what They say
Pat