If there's anything that accumulates as quickly as binder twine it's feed bags. If you're lucky enough to have horses that are healthy just eating hay or grass, you'll not have this problem. But those of us who feed grains and concentrates will likely have a stack of either burlap or bristling plastic bags stashed somewhere.
In by-gone days, you used to be able to return these bags to the feed mill and they would pay you a dime a bag. But worries of bags containing contaminants and bags being in poor condition have ended this practice. Now we're left with dozens of bags with no job. However, feed bags, just like their kin binder twine, can be useful around your home and stable with a little ingenuity.
Recycling for these bags does exist in some areas. Inquire at your feed store to find out if this is an option for you.
Using burlap bags to protect trees and shrubs during the winter months is one obvious use. David Beaulieu, About.com Guide to Landscaping describes how to wrap your trees against wind and snow damage. Cut the sides of the bag open to make the pieces longer. You can attach them together to make a longer wrap. I keep an ancient heavy duty Singer sewing machine to sew projects like this (along with minor horse blanket repairs), but you can probably get by just wrapping and using binder twine to hold all the pieces to the tree. Smaller shrubs might get wrapped by simply slipping the bag over top. In the same way, use the bags to protect wood and trees from bark and wood chewing horses.
Burlap bags also make good lawn clipping and manure disposal bags. They will rot over time, but if they are going in a municipal waste composter, make sure they'll accept them. Feed bags—whether plastic or burlap have lots of uses in the garden. Use the plastic bags to mulch the foot paths between rows. Use burlap bags to shade or darken beds of delicate seeds like carrots and lettuce. They hold the moisture, so will help some seeds germinate and prevent lettuce from bolting when the weather is the hottest. Burlap is good for protecting plants from frost, but I've found that plants under plastic aren't well protected.
Burlap sacks can be laundered (if you're willing to put your washing machine through this), and used for crafts. Cut into strips they can be woven into rugs,and they're a given when creating a scarecrow. They can be used for any number of other creative uses. I've even seen ones with folksy printing that I thought would look great stretched on a frame for a wall hanging. Here are a few interesting ideas from creative About.com Guides:
Budget Decorating Ideas with links to wall hangings, planters, corkboards and wreaths.
Scrapbook Pages (I could definitely see scrapbooking a season's show memorabilia against a background of a printed feed bag)
Mr. Potato Head costume
The plastic feed bags have their uses too, but they aren't as durable or decorative as burlap. They tend to break down in the sunlight. The beige bags seem to be more hardy than the white ones. But both should survive a summer or even longer if you keep them indoors. I made a clothes pin bag out of one, and it was flaking away by autumn. So you have to decide how long you want your finished project to last.
Of course, the most obvious use is as garbage bags for dry trash. Anything wet will leak out. You can also bundle up kindling and firewood, bulk shavings for your stalls and use them as drop sheets. I've seen large round bale bags made from them and they seemed to weather about the same the 'official' purchased version.
You can make a quick hay flake bag out of either type of bag. Simply cut a 'horse-nose-sized' hole in the side of the bag. Cut small slots to run twine through around the open end of the bag and fill the bag with hay. Pull the top of the bag closed and tie it high so the horse can reach the opening, but not get entangled. Feeding hay at head height is not good for horses over a long period of time.
So have you found a great use for feed bags that you'd be willing to share? How do you re-purpose feed bags.