probiotic comparisons

[Carol.Boardman@Dartmouth.EDU (Carol Boardman)]

I'm wondering if anyone can give me the ingredients of the ABC priobiotic
compared to the Fastrack brand.  Do you recommend one over the other and why? 
What about dosages / comparable cost?  I have a 17 yr old Arab that we're
having a bit of trouble keeping weight on during competition season even when
we increase her grain (per vet instructions) and stuff all the grass hay into
her that she'll eat.  She's also on 12 hour turnout on grass during the days. 
Not much grass now but as the summer comes on there's more than enough in the
pasture for the horses pastured on it.  Any thoughts would be helpful.
Thanks so much.
Carol Bushway-Boardman in Vermont and Sambucca (More food! more carrots!)
carol.boardman@dartmouth.edu