That's what I've used, too.  But folks tell me it lacks the "Mother," the part with the good stuff in it that you can't find at most grocery stores.  I did call around and find 2 grocery stores that carry the ACV with the Vinegar, Bragg's brand.  It's more pricey, but I think it might be interesting to try for a change.  I figure I can buy one bottle of it and try it out and see how the chickens take to it.  Who knows?  Maybe they'll like the filtered kind from the regular pasteurized store brands better?  But everyone seems to feel the Bragg's is far superior.  But that academic mentioned it can harbor bad bacteria and E-Coli, unlike the filtered store brand.  Although she did say that the chance of bad bacteria is lowered by the Ph of the vinegar, but if the Ph has lowered, for any reason, it could be hazardous.  But I think I'll try it once, for the hens.  I still don't know whether this stuff is good for roosters or not.