Question

On a recent horse-buying trip to Europe, I noticed that silage is frequently fed to horses. Is this the same feedstuff fed to cattle in the United States, and is it safe for horses? What’s the difference between silage and haylage?

Answer

Silage is chopped forage that retains its succulence through anaerobic fermentation. Silage usually contains grain plants such as corn. Haylage is also a fermented forage but typically does not include grain plants; it’s made entirely from grasses or legumes. In the United States, silage is more often fed to cattle than horses, as you have observed. Horses are fed hay in the United States because the weather is typically dry enough to allow for mass cultivation. In countries such as England or Netherlands, rainfall may preclude the production of hay, and alternative forages must be sought.

When preserved properly, silage is an acceptable feed for horses. Silage should be green or greenish-brown, be uniform in texture and moisture content, and have a pleasant smell. Due to the high moisture content, silage may be an excellent feed choice for horses with respiratory problems such as chronic obstructive pulmonary disease (heaves).

If the fermentation process goes amiss, however, mold and bacterial toxins may proliferate in silage. Moldy silage has been implicated in cases of colic and botulism.

Therefore, horse owners must carefully weigh the benefits of feeding silage against the potentially fatal side effects of spoiled silage. Because of these risks and the abundance of hay available, silage is not commonly fed to horses in the United States.