Alfa-A for old horse who doesnt keep weight on, hifi for horse who does and needs some energy, happy hoof for the ponies and another oldie who does maintain weight..
Alfa A as horse is slender (lol) and needs the alfa to supplement his soaked oats diet. My feed merchant told me hi fi was just glorified straw! And Id rather not feed glorified straw at Dengie prices so used an own brand lo cal chaff on my last good-doer.
I feed Alpha-A at the moment; I used to feed hi-fi to my old horse because he went a bit mental on Alpha-A. I like my current horse mental though - she is more fun with a bit of zing.
I use chaff (not alfa-a but don't think its hi-fi but it could be) and i can't stand alfa a, its so dry, mine is oily and garlicy, so much nicer for them.
Alfa A in the winter - It is a good source of protein. Then when the grass is out in the summer I convert to Hi Fi which has the fibre without so much energy.