The majority of the equine diet should be based on forage, which serves as a source of fiber and nutrients. However, some horses might not readily consume all types of hay. To that end, a team of California State University researchers set out to compare four hay types to determine which horses are most inclined to consume.

Hay palatability depends on a variety of factors, such as species and maturity at harvest. In addition, some hay types might not be suitable for all horses, depending upon individual nutrient needs for maintenance, work, growth, or reproduction. In the current study, led by Anne V. Rodiek, PhD, researchers evaluated horses’ voluntary intake of alfalfa, oat, wheat, and teff.

The study involved eight mature mares housed in individual, partially roofed pipe pens. During a two-week adaptation period, all horses received one flake of each hay type daily (alfalfa and wheat hay in the morning and oat and teff in the evening). During the following four-week evaluation period the horses were paired and fed the same hay at the same time.

The team separated the horses into four groups of two, each of which consumed each type of hay alone for one week at a rate of 2.2% body weight (as determined by a weight tape) increased to 2.5% body weight if the horse consumed all the hay during the feeding period. The researchers removed any leftover hay prior to the next feeding and weighed it during the last five days of each week to calculate voluntary intake