My mare and my gelding are currently pastured together at the boarding farm. They are kind of like Jack Sprat and his wife: my gelding is a 28yo hard keeper and my mare is a 20yo easy keeper. They are together because we (the folks who run the farm and I) want my gelding to be on grass, but my gelding is so bonded to my mare that if he's separated from her all he does is trot around anxiously, calling and wasting energy. In the morning and evening they get grain as well, but they can't be on the same kind because he needs stuff with a higher fat content than she does. Well, of course she's the boss of him and when she is done eating her grain she walks over to see what he's got and he lets her have it. Taking him out to be fed separately is not a possibility (unless I pay someone to go over there and do it, which I will if I have to but I'd rather try other things first) so I am considering putting something in her bucket to try to slow her down. I know some people whose horses eat too fast will sometimes put large, smooth rocks in their horses' buckets. Another friend suggested using a length of chain as well. If I used a length of chain I would want it to be stainless steel so it wouldn't rust, and I'm finding that not only is it difficult to find stainless steel chain but it's also kind of pricey. Which would you use, big rocks or a length of chain, and why?