Horse diet question?

I recently got 12 bales of Canadian Hay, and the guy I bought it from says that it is alfalfa hay. I've been told that alfalfa is really bad for horses.
My 4-H leader claims that it is horrible for horses.

I'm Currently feeding my 850 pound 17 y/o Morgan 11oz of Blue Seal Vintage Sweet and Blue Sea trotter, and i'm Mixing about a half flake of the Alfalfa hay with regular 1st cut grass hay. I feed him this twice a day.

I also feed my 400 pound 18 y/o Shetland/welsh pony cross 5 ounces of the sweet fead and pellet mix, with a little less than a half a flake of the alfalfa.

Do you thing that's an appropriate diet for them?


Also my alfalfa hay looks like this -

Alfalfa is not horrible for horses... Although grass hay may be more nutritionally balanced, some Alfalfa in the diet is fine for horses. How much does each flake weigh? Flakes can weigh anywhere from 2-10 pounds, so I have no idea whether you are feeding 1 pounds or 5 pounds. When my horse is only being fed hay in winter (no pasture) I feed 5 pounds of Alfalfa and 15 pounds of grass hay.