Sprouting Grains/Grass For Animal Feed?

I’ve seen many methods of sprouting barley t9 produce feed for animals, but I have a few questions l hope people might answer.

One, has anyone experience with anything besides barley? Ive seen reports that this is one of the better grains to do this with, mostly due to growing speed and vigor.

Two, could this be done in a self sustaining manner? Could one grow enough to sustain say 5 or 6 cows over the winter of zone 6b/7? I saw a post where a guy did this for several cows and a few other animals, and it didnt seem too intensive.

Third, wouldn’t it make more sense to just have a hay plot? I dont see why the sporuting is done unless you just want the animals to have fresh feed.

Fourth, what would the nutrient profile of sprouts versus say the grains themselves? Wondering how this plays.

Any thoughts or experience would be appreciated, thank you!