The importance of recognizing hay quality for horses

Weather conditions make hay production difficult this year

An open area of land with carts filled with hay
Photo by Tim Williams

If you’re a typical horse owner in the Midwest with limited access to quality pasture, you may be getting more than a little concerned about finding hay.  Many horse owners have been out for some time and have found prices sky high at their local hay auction if there is any decent quality to be had at all.  Further, given the amount of rainfall we’ve had this spring, many hay producers are having a difficult time getting in the fields to harvest first-cutting which typically happens around Memorial Day, or getting hay to dry properly if they can enter the field. Going into a wet hay field and damaging it puts good second cutting at risk as well.   Finally, for those producers growing crops in addition to hay, the issue has been further compounded by efforts to get corn and soybeans planted first, which is the traditional time table.  For the Michigan horse owner,

Horses are what are known as “trickle feeders” which means that the gastrointestinal tract is designed to consume small amounts of feed continuously to function at its best. Horses at maintenance or performing at a light workload should consume feed at approximately 2% of their body weight each day, which for the average 1,000 lb horse equates to at least 20 lbs. In the wild, horses graze forages roughly 18 hours each day, and move while doing so.   In domestic situations recommendations for the average adult horse at maintenance are that forage in the form of pasture or dry hay make up at least 50% of the total ration, although for some horses, a completely forage-based diet will suffice. For those with large pastures and appropriate stocking rates, this may solve the hay shortage problem this summer.

Hay with 30% alfalfa/legume or less and 70% grass is adequate to meet the nutritional requirements for most equine life stages. Nutrient quality in hay is dictated by plant maturity. As plants mature, they become more fibrous, which can limit the amount of nutrients available to the horse.  Grass hay with observable seed heads indicates maturity and may require the addition of grain or a ration balancer, depending on the horse’s nutritional requirements based on their workload, growth rate, production status, or body condition score.  Having hay tested is one way to determine overall hay quality, and understanding how to interpret the results will assist in making feeding decisions.

Unlike most other species, horses are often used in athletic endeavors that require optimum respiratory function.  As a result, horses require forage free of excessive dust and mold, which can aggravate the respiratory system and potentially cause Chronic Obstructive Pulmonary Disease or Heaves, which is progressive and while manageable for a time, potentially career and ultimately life ending. Hay that is harvested in wet conditions or that does not adequately dry prior to baling may develop mold over time.  In addition, wet bales are more likely to combust while stored resulting in a barn fire.  Typically, wet bales will seem unusually heavy when moved.

Hay should also be free of plants toxic to horses such as Hoary Alyssum, which is endemic in many parts of the Midwest.  Hoary Alyssum may cause edema or “stocking up” and in serious cases, founder.  While well-fed horses tend to avoid Hoary Alyssum while grazing, they may consume it in dry hay.  The plant itself has seed pods on the stem, making it more easily identifiable in hay.

Finding good quality hay for horses may be a challenge in the upcoming months, and depending on weather patterns, possibly years.  Horse owners in the Midwest may be well served by focusing on pasture management to minimize the need to feed hay in the summer, developing storage systems to buy appropriate hay quantities at reasonable prices, and considering hay alternatives such as hay cubes, when the need arises.

Visit the Michigan State University Equine Team’s site at

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