Pregnant mare nutrition question

So, since our mare is mysteriously pregnant and I've never owned a mare (only geldings) before and certainly never dealt with pregnancy or foaling I have a couple questions. First of all, can anyone point me in the direction of some good information on proper nutrition, hay selection etc.? She was not being fed very good quality hay, which is why we removed her from her previous boarding facility, and is now at a friends place where we are caring for her. Consequently she has the big belly from being preggers, but is ribby and looks muscle wasted to me along her topline. We have been feeding her alfalfa and oat hay. Also, I'd really like to get some GOOD weight on her and wanted to know if anyone had any good suggestions on supplements and the such. Thanks!

It's a pain in the butt but I would go with Beet Pulp and lots of it if she will eat it. You need to give her calories but not overload her with sugars as pregnant mares are very prone to edema, dehydration and colic. Beet pulp, soak it so that it's nice and wet and won't blow up in her belly and dress it with something she likes to eat. Then mix the good stuff with the beet pulp and try it. You might have to buy syrup or sometime to add to it to make it more palatable but it is very good for putting weight on a ribby horse safely. As long as you wet the stuff down good to get it to expand before feeding then you really can't overfeed the stuff as they will eat until they are full. I am putting weight on a supposedly pregnant mini-donkey this way and she gets gut fill before she gets enough to put weight on AND support her pregnancy so she is on a full bucket of beet pulp and her regular ration of pelleted feed every day. She munches on the beet pulp throughout the day and gulps her pellets as soon as she gets them. It wouldn't hurt either to put her on a formulated mare and foal food or supplement to help her get everything she needs.