Please Help Me With My Minis!!!

Hi! Well, I knew my mini mare and and gelding were obese as soon as I got them I started working on there nutrition, but I just realized how fat they are :'(. Please help! Right now they have no grass due to the ground eighter being muddy or snowy and are getting no grain. We have about 10 round hay bales that they eat off of and that is it. Once spring comes around and they can go into the small lot I am planning on taking them off of hay except for some in the morning and they will be allowed to graze on the lot (I think it is 5 acres, theres 3 minis) 24/7(they keep this grass very short so it is of minimal nutritional value, mainly just so that they don't get bored and decide to start cribbing or something like that). I am not there to work them except about 3-4 times a month in the spring/summer/fall and only 1-2 times a month in the winter. So, what should I do as far as excersizing goes and how about a diet? As I said, I knew they were fat but looking at a pic from the front, I realized just how heavy they are. Here are some pictures.

Thanks,
tcg

btw- does Jake (the horse in the last pic) look too heavy to you? I know he could stand to lose a few but, is he fat or just stocky?

I know this might come across strong, but I am in no way shape or form trying to be mean. I'm just curious. Who takes care of them when you're gone? Why do you have horses if you can't be there almost everyday with them?
I was going to suggest training them, maybe to jump or something, but seeing as you can rarely make it to the barn, I have no answers. I'm sorry. Good Luck with them :)

thats fine, honestly I'd problably be wondering the same thing if I were reading this :d. Anywho, I keep them at my grandmas and her friend has cows next to her property so he comes over in the mornings and feeds everybody. I am not able to be there except on the weekends. I know its not the best situation but hey, atleast there not in the killpen or something equally evil. They are getting taken care of, I am just not able to do it. As for training to jump, Misty(the black one) is only 1 and bell(the paint) is still working on learning to lead. Copper(flaxen chestnut) is being trained to jump though.

thanks,
tcg

Unfortunately, the free access/round bale feeding is going to make any weight control impossible.