I also have my own farm and have 4 ponies, all with different situations so I feed accordingly. 2 are retired ponies and are quite chubby right now, one is a young pony who needs all he can get and 1 pony is in good weight and works quite a bit.
My guys are out 12hr a day right now and in at night. They get grain before turnout (handful of grain for the retired guys, 2 cups of grain for the guy in good weight, and 4 cups for the young pony who needs the calories right now. They also get different types of grain since they are doing different “work”).
All of my ponies go out together as we have one winter paddock. They get one small square bale in the am that lasts them from 6am to about noon. I don’t feed much more as my retired guys are quite large right now so round bale is not an option.
I bring in around 6pm and they get the same grain they had in the morning, a handful of hay for the retired ponies and 1 flake each for the 2 in work (and a good amount of soaked alfalfa cubes for the young pony). If I’m going to work the ponies around 6pm when I get home, I do feed a couple of flakes of hay as soon as I get home outside to all 4 ponies. This keeps them all happy and the one or two I’m about to work has something in their stomach.
I also do a night feed around 9-10 and they all get 1 flake of hay and my young guy gets another serving of grain. I do cut back a bit on the grain for the young pony if I’m not working him as he will get a bit too much energy. Once the summer comes, they are all out on a large 4 acre grass paddock and come in at 9pm with a handful of hay and their regular grain.
Also meant to add, I’m not an eventer but do combined driving with my guys. So they need the energy but not the “hotness” that can come with it. I’m fairly picky on their grain and I’ve shopped around for the best fit for them and have spoken to a lot of different feed reps to find the perfect fit. Hay and grass are a huge part of their diet though and I try to feed as much of that as possible.