I found a list on another forum. Strategy has 28% NSC(non structural carbohydrates ),
Grass hay around 13, alfalfa 11, oats 54, just to throw some numbers out there. Ideal would be an overall percentage of 20%, 15% being better. There are other Purina feeds with less NSC, like, to stay with the Strategy line, Strategy Healthy Edge with 18% and a nice fat content for energy.
Even if hay is hard to find, and expensive, it is needed for gut health.
Horses are trickle feeders, constantly munching on something, their stomachs are small, produce acid constantly. An empty stomach means the acids start digesting the stomach lining, horse develops ulcers. So, keeping something in there at all times is the way to go. Hence the slowfeeder nets. I used to ground feed hay, basically free choice, until I started weighing how much I put in and how much I raked together next day. Shock!...20-30lbs WASTED. I made nets myself, baling twine works well and is free, left them filled all the time. Now my horses regulated their intake to about 15lbs each, only a handful on the ground, and they look great.
As I said, for "grain", the Arab gets a handful of alfalfa pellets, soaked, with his supplements, the Quarter, bigger and taller, also the alfalfa with a little over a pound of ricebran and her supplements.
I have different types of hay, orchard/timothy, oat hay and 3-way(wheat, oat and rye), and every net has a different hay. They do wonder between them, eat a little oat, then go to the o/t, and so on. I'd love to feed o/t only, but I pay pharmacy price, 21$ for a 85lb bale. Oat and 3-way is 10$ for 100lbs.