It is actually MUCH healthier both mentally & physically for horses to be out on pasture and/or just fed hay. Horses evolved as trickle feeders that are supposed to eat small amounts of relatively nutrient poor food all day long. Pasture is even better for their teeth as the grass/hay requires more chewing so grinds the teeth down appropriately as well as aligning the teeth correctly when their heads are down. All in all we cause horses a lot of the problems with horses, both behavioral & health when we keep them in stalls all day & feed them concentrates. I could literally go on all day with all of the reasons and research behind why it is healthier for horses to be on a forage based (pasture/hay) diet, but I won't
because a lot of people tend to find it annoying! LOL, sorry.
I don't deny that SOME horses need extra rations beyond pasture or hay esp if the forage is of poor quality... but in reality that is very far and few between. Even your horses that receive moderate exercise 2-3x a week are fine on a quality pasture/hay. That's the category most of our horses fall into
. Of course it needs to be decent pasture...not something that's primarily dirt and weeds. When I was younger I used to be on the stall/concentrate side, but now all I've learned in school has completely changed my mind.
Sorry I'll get off my soapbox now...