A close look at teff as a forage option for horses. Hay comprises the majority of a horse’s diet. Therefore, when owners are able to source a forage that complements their horse’s nutritional requirements, there are numerous benefits. These benefits range from ease of management to better equine health and even lower feed bills. Teff is a species of grass that is gaining popularity for use as horse hay. It is thought to be a great option for both easy-keepers and metabolic horses.