I think in this case, I'd rather see you put out too much hay than too little. They should get at least 1.5% of their body weight in forage, but in winter they may need more to keep warm. In general, I don't recommend just dumping out a round bale-they stand around and eat and poop in one place, but I'd rather that than the feast/famine of only feeding once a day and possibly wasting what you do give at that time by pooping in it.
I would possibly even see about getting a round bale of straw (no grain heads, just the stems) for a filler he can munch on during the day, then give him his nurtirious hay at night, and I don't know a horse that would be too full of straw to turn his nose up at the good stuff. Even stemmy grass hay (but don't get fescue, orchard or brome-they are high in sugar and will fatten him up) if you can find bermuda or just a mixed grass and sample it to test for NSC (sugars and starches that make it fattening).
Otherwise, having your mom dole out half the ration at another time of day is still preferable to only being fed in the eveing.
Personally, I feed my 4 several times a day. Any supplements (grain or senior feed, etc) first thing in the am, and a couple of flakes of hay each. Then by noon, I put out more hay. Late afternoon, hay again, the second supplement feeding (I do have an old horse that needs his extra calories). At night, right before my bedtime, I put out the rest of their hay (most of it goes out at this time for a reason- longest stretch before I come to feed again, it's the coldest part so they need more fiber to keep warm, and entertained- then during the day, if I have a chance to ride between appts, they aren't missing an important meal or their schedule). I know it's hard to duplicate that when they aren't at your own place, though, or you work/school for long stretches during the day. I also spread it out in many piles to eliminate fighting over the hay, and to get them some exercise. It's more work for me, but I need the exercise, too! For my mini in the dry-lot- I put it in racks around the fence line and he and the goats still have to move around to eat, without wasting it (he's bad to pee on it if it's on the ground). The racks are ground feeders, but he can't get into them, and it slows him down, so he eats less in a given time period.
So back to the round bale dilemma-I'd do it. Just don't buy rich hay like alflalfa or clover or sugary grasses and cut out any grain.
Last edited by barefoothooves; 12-02-2009 at 10:07 PM.