Hi Mary,

One of the ways you can tell how much hay is being eaten is to weigh it before you put it out and then weigh whatever's left after 12 or 24 hours.  If you do that for a few days you should be able to get a good idea of what is being consumed and it'll probably be pretty consistent from day to day.

If you feed the Timothy Balance Cubes they are balanced to themselves and only need salt (yes iodized), vitamin E and flax added in.  If you're still using hay you'd want to balance that and CA Trace may or may not be appropriate depending on test results.