She is in a 12 acre pasture 24/7. She gets A LOT of forage everyday (green grass and has the option of eating from a round bale). I only feed her a pound of Golden Performer 14% a day (1/2 a pound twice a day) as well as one flake of coastal hay twice a day. I only ride her for about 1 hour and 30 minutes three times a week at the most, but her exercise will increase once I have more time.
I've read that forage is 70-80% of a horse's diet, and that green grass contains a lot of fat and sugar and can cause obesity in some horses.
Will keeping her in a stall at night help her to lose weight since she can't eat grass all night? If I take away the round bale, will that help by taking away another source of forage? Should I feed her even less feed, or does she need the extra calories since she's exercising?
I would love to get some advice because this is the first time of tried to diet a horse!