Cuts, Quality, Storage, Rain, Colour: Separating Hay Facts from Fiction

Horse people are often described as picky, fussy or difficult when it comes to hay selection. This description is not surprising because many horses are either very valuable or viewed as part of the family.

It is often a lack of knowledge about selecting quality hay that gives horse owners a bad name and forces them to pay more for hay than their neighbors with other types of livestock. Myths develop because of a piece of truth that becomes inflated and held as absolute truth without justification. To improve our knowledge of hay selection, here are a few common myths about hay, how these myths came to be accepted and, finally, “the truth.”

(Note: For the purposes of this article, “high quality hay” refers to hay with a high nutritive value.)

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Myth: Second cutting hay is always the best cutting.

How it came about: The number one factor that determines hay quality is stage of maturity at harvest. Cool season grasses such as orchardgrass and timothy will produce a seedhead in the spring, often just in time for the first cutting. For the hay producer, this means an increase in yield and therefore more bales can be harvested and sold. However, this also means that fiber is elevated in the crop, therefore reducing quality. Because seedheads are only produced one time per year in cool season grasses, subsequent cuttings do not contain them and second or later cuttings will be generally less fibrous as a result. Second cuttings tend to cure more quickly and are less likely to experience rain damage; both contribute to higher quality relative to first cutting.

Truth: First cutting hay can be high quality if cut early and second cutting can be low quality if it cut late. Stage of maturity and other management factors affect hay quality at harvest. High quality (or low quality) hay can be harvested from late spring to late fall if weather and management conditions are right. Quality should never be assessed based on cutting number, but on a laboratory-performed analysis.

Myth: Horses require higher quality hay than cattle.

How it came about: Some horses, especially those with high nutrient requirements, do require higher quality hay than cattle. Horses and cattle have very different digestive tracts. Cattle are ruminants and are able to breakdown fiber very efficiently, whereas horses are monogastrics with a functional large intestine (hindgut fermenters) and are less efficient at fiber digestion. Therefore, cattle can perform well on lower quality hay that horses cannot digest well.

Truth: Individual needs of the animal should dictate the quality of hay provided. An easy-keeping Quarter Horse in light work does not need the same quality of hay as a Thoroughbred at the peak of its racing career. Similarly, an open Angus cow does not need the same quality of hay that a high producing dairy Holstein needs at the peak of lactation. Consider the current body condition, level of work and pasture availability of your horse. Then choose hay that will meet the needs of your horse without excess based on a hay test.

Myth: (Fill in the blank) is the best type of hay.

How it came about: Statements such as this often come from horse owners that have moved from one area of the country (or world) to another and are not accustomed to the local hay. Different forages are adapted to different soils and climate conditions, so the most common hays available for horses vary among regions.

Truth: Hay quality is not about the forage species or even the variety. Forage species used for hay will fall into one of two categories: grasses or legumes. Grasses can include orchardgrass, Kentucky bluegrass, tall fescue, bermudagrass, timothy, teff and smooth bromegrass. Legumes include alfalfa, red and white clover, lespedeza and birdsfoot trefoil. When managed and harvested correctly, legumes will be higher in quality than grasses; however there will be little difference between different grasses or between different legumes when all other factors are held constant. Buying quality, local hay will likely save money due to reduced transportation costs. Make sure to address any concerns with a specific grass or legume species, such as endophyte infected tall fescue. If you are concerned about feeding a certain species of hay, ask your local county extension agent or equine nutritionist about it.

Myth: Forage stored as round hay bales or as silage contain diseases such as botulism and should not be fed to horses.

How it came about: The botulism bacterium prefers moist conditions and is commonly found in the soil, in stream sediments and in the intestinal tracts of fish and mammals. Silage (haylage) by definition is stored with higher moisture than hay, and when not properly handled, can allow the botulism bacterium to flourish. Hay that is conserved in large round bales is usually baled at a similar (often lower) moisture content as small square bales and thus is different than haylage. However, if round hay bales are stored outside, they can get wet from rain, encouraging the growth of bacteria and mold.

Truth: Proper storage, handling and feeding of round hay bales will minimize the risk of botulism in horses. Round hay bales should be covered when stored and fed using a hay feeder to reduce contamination from trampling and urination. Round bales that show clear signs of mold should not be fed to horses. Feeding silage to horses is much more common in other countries than in the U.S. Silage should be put up at the proper moisture content for the style of storage, kept airtight until feeding and fed quickly to reduce the risk of botulism. Silage should always be tested for forage quality before feeding. In botulism prone areas, a veterinarian should be consulted about the use of silage and the inclusion of a vaccination against botulism to protect horses.

Myth: Don’t feed hay that has been rained on.

How it came about:

Rain negatively affects hay in a variety of ways:
Rain on recently cut hay can prolong plant respiration and reduce energy content.
Rain on legumes will cause leaves to separate from the stems (called leaf shatter) and therefore remove the more nutritious portion of the plant. Fibrous stems will then be more concentrated in the final product, causing a decrease in quality.
Rain will also cause leaching of sugar and other carbohydrates, proteins and minerals.
Heavy rain can splash soil up onto curing hay, which can increase dustiness and rapidity of molding.

Truth: Rained-on hay can be acceptable quality. While rain usually negatively affects hay, to what degree depends on several factors, including what type of hay is being harvested, how much/how intense the rain fell, stage of curing when it rained and what the producer has done to counteract these negative effects. For example, if light rain occurs within a day of cutting, it has very little effect on hay quality. All hay, especially material that has been rained on should be tested for quality and inspected for mold or dustiness before use.

Myth: Hay should be stored for six weeks before feeding.

How it came about: This myth likely came about from hay testing. After hay is stored in a barn, it will continue to cure for four to eight weeks. During this curing period, the quality of the hay can change slightly.

Truth: Hay can be fed at any time after harvesting. Hay should not be tested until it has been stored for six to eight weeks to increase the accuracy of the hay test. While feeding hay sooner will not be harmful to horses, it will be difficult to balance the ration because the quality of the hay is unknown.

Myth: Green is good; brown is bad.

How it came about: Often, hay that has been harvested too late or mishandled will lose its green color due to processes such as heating and bleaching. Green hay is less likely to have gone through these processes and more likely to be of quality.

Truth: A hay test is the only way to truly evaluate quality. No quality factors directly affect color or vice versa. Therefore, color is an inconsistent factor to evaluate the quality of hay.

Myth: Feeding hay causes a large, distended digestive tract, known as a hay belly.

How it came about: Hay belly usually results when malnourished horses are provided large quantities of low quality, high fiber hay. The horse will usually be thin over the neck, withers, ribs and hindquarters; however the belly will appear large because the horse is consuming large amounts of hay.

Truth: A balanced ration that includes quality pasture or hay will maintain a horse at an ideal condition without excessive gut fill.

It is important to remember that horses evolved consuming forage, and whether in the form of pasture or hay, is an important component in the equine diet. Choosing hay for your horse will depend on your horse’s current condition, work level, pasture availability and the logistics of management on your farm. Hay should always be inspected and found to be free from contaminants such as weeds, insects, mold, dust and other foreign material. The nutritional value of the hay should also be evaluated prior to feeding so that a ration can be formulated that will meet the needs of your particular horse.

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~ Krista Lea, MS,; Ray Smith, PhD; Chris Teutsch, PhD; and Jimmy Henning, PhD, June 2021 Equine Science Review, University of Kentucky