Originally Posted by Production Acres
You don't want to get the mare fatter; but, she needs to be busy at feeding time as well as the other animals. Find a cheaper hay to feed her - something with less rfv than the hay you are currently feeding, and let her have at it. Animals can actually loose weight eating hay if it is cheap enough(low low rfv). There is no shame in using a cheap hay for a purpose!
I agree with this. My old barn fed alfalfa but in very limited amounts. So I provided my own timothy for him to much on through out the day. The BO's would tell me my hay was crap and my horse would just poop on it, but I didn't care. I bought the cheap stuff for a reason, if he wants to eat it, he can. If he wants to poop on it, whatever.
Horses naturally graze 17 to 18 hours of their day. They should be eating 10-20% of their own body weight in forage daily. So overweight or not, a flake every other day to me isn't right. If this is what the owner wants, then I guess theres not much you could do, but maybe you could ask the person who feeds to throw him some scraps or something so he thinks he's not being ignored. You could also get some cubes to give on your own. Just a handful, soak 'em up good, he might really like that.