Ground linseed
Linseeds are valuable in horse feed, among other things due to their mucilage. To allow the mucilage contained in the seed coat to be released more quickly, not only whole linseeds but also ground linseeds are used in feed.
In addition, ground linseed is more easily and completely digestible than whole linseed and still contains the full amount of oil and therefore of omega-3 fatty acids. However, grinding also causes linseed to turn rancid more quickly. For this reason, ground linseed is used relatively rarely in feed mixes for reasons of shelf life.
Incidentally, alongside ground linseed there is also linseed extraction meal, which is used as a protein source.
More information on linseed: Linseed extraction meal, Linseed, Linseed oil