Hay, Haylage and Silage: What’s the Difference?

For the horse owner the onset of fall weather can signal the start of the search for storable forage before winter begins. Considerations such as forage type and storage form nutritional content palatability and cost all become important.
Horses are classified as nonruminant herbivores. They are adapted to eating plant fibre or forage sources such as pasture or preserved forages such as hay haylage or silage. Horses can utilize fibrous plant material very successfully through the hydrolyzation of simple carbohydrates and other nutrients in the stomach or foregut and the fermentation by microbes of complex carbohydrate sources in the uniquely adapted hind gut. The energy derived from fibrous plant material is generated as a result of the fermentation of carbohydrates like cellulose by the natural microbes living in the hind gut of a horse.

Fermentation of these carbohydrates results in short chain fatty acids called volatile fatty acids VFA. They are utilized by the horse as an excellent source of safe energy.
Horse are happiest when they can browse or forage for food for at least 10 to 15 hours per day. In summer this can easily be provided through the feeding of fresh forages in the form of pasture. Weather prohibits the utilization of pasture as a forage source for a large part of the year in Canada. Canadian horse owners have a yearly objective of sourcing quality stored forage for our horses to consume in the coming winter months.  There are few things more satisfying for the horse owner than a successful search for winter feed that results in a barn full of good hay!
Forage preservation methods
Forages for horses are most commonly preserved for storage in the form of hay haylage or silage. The first step in preparing any kind of forage for preservation is the cutting and the subsequent wilting of the grass by the sun and air as it lies in the field. As forage is wilted the moisture level drops and the dry matter percent goes up. The amount of moisture present in the forage when baled will dictate whether the feed is stored as hay or ensiled as haylage or silage
What defines hay?
Fresh grass when cut generally has a moisture content of at least 80 percent resulting in a dry matter value or DM of 20 percent or less. Cut forage intended for hay must be allowed to dry in the field to a moisture level of