Everybody knows that what the horses eat is important but we didn't have a clue that it was so extremely important also how they eat. Today I seriously wonder if it isn't more important how they eat than what they eat.
http://www.swedishhoofschool.com/hayfeeders.htm
An even more technical approach, for the handy man:
http://www.paardnatuurlijk.nl/onderzoek/dispenser.htm
It's in dutch, but pictures will explain for themselves.




