Hay Selection for Horses
Aside from pasture, hay is the predominant forage consumed by horses, so its value in equine diets is unquestionable.
During certain times of year, hay may be the only forage available to horses and therefore the selection of well-preserved hay harvested at the appropriate stage of maturity is critical.
Hay can be classified into three general types: legume, grass, and mixed.
Mixed hay is usually defined as a blend of grass and legume plants, though some hay producers and horse owners may define it as a combination of several grasses.
Like most horse owners, Kathleen Crandell, Ph.D., has opened hundreds of bales of hay during her lifetime of owning and caring for horses. While most horse owners are mindful of the hay they offer their horses, Crandell is perhaps more vigilant than most. As a nutritionist with Kentucky Equine Research (KER), she understands the importance of good-quality hay.
Legume Hay
When evaluating legume hays, Crandell first establishes the type of hay. Although the most popular legume used among horse owners is lucerne, other legumes such as clover and subclover are often fed, and these provide horses with high-quality nutrients.
Evaluating hay requires a thorough visual appraisal. Because the outside of a bale can be misleading, especially if it was situated on the edge of a stack with exposure to the sun or other elements, appraisal necessitates breaking open several bales. Small bales can be opened easily, but the same cannot be said for larger round bales.
Pure legumes are rarely roundbaled, but if faced with tightly wound round bales that cannot be opened, an instrument designed to remove core samples from the inside of hay bales, called a hay probe, can be used. Probes are used to collect hay samples for chemical analysis and nutrient determination. Hay collected in the probe should be assessed just as carefully as that in entire bales.
Crandell next evaluates the colour of the hay. "It might be bright green, brownish-green, or pale green, or it might not be green at all; perhaps it is yellow. Colour is not the end-all, be-all in determining hay quality, but it can be a clue to how it was made. If it is bright green, then I know the hay was likely cut at an appropriate time, that it was probably not rained on after cutting, and that it dried quickly and was baled in a timely manner. When baled under optimal conditions, the most nutrients are preserved."
It is not unusual to run into bales that have both green and brown plant material, according to Crandell. If the leaves are brown, the hay is likely to have less nutritional value, as leaves deliver the most nutrients. If, on the other hand, the occasional stem is brown but the leaves are green and well-anchored to the stem, then the hay is probably still nutritious.
"Yellow, brown, or otherwise faded hay indicates that it was made at a mature stage, laid in the field longer to dry, or possibly rained on after being cut in the field, all of which would indicate lost nutrients through leaching by the sun or rain," said Crandell.
Aside from colour, probably the most important criterion when selecting legume hays is leaf-to-stem ratio. A profusion of leaves and few stems indicates that the hay was made at the desired maturity and that few leaves came loose during baling. The opposite is often true with legumes, and these hays sometimes have an abundance of stems and few leaves. This usually means that the leaves came off during baling or when the hay was lying in the field.
"I also look at stem coarseness, as this tells me the stage of maturity of the plants when they were harvested. The stem contains few nutrients and a great deal of indigestible fibre. Aside from marginal nutrition, if the stems are too mature, horses do not particularly like to eat them," added Crandell.
The presence of mould, unusual growths on leaves, insects, and suspicious plants is noted. "I might shake a couple of handfuls to see how much dust flies off. Almost all hay has some dust, but if a large cloud erupts, it's probably best to pass but imperatively so if you have a horse with a respiratory ailment aggravated by dust."
'I almost always try to smell the hay to see if it is fresh, stale, or mouldy. If the hay was baled wet, it might have a distinct smell that results from caramelisation of proteins," remarked Crandell.
Other Legumes
While lucerne is the most well-known legume hay, clover hays are appropriate for horses, even if they are not as popular with horse owners as lucerne. One reason horse owners often avoid clover is its propensity for mould. Getting clover to dry quickly in the field is challenging for growers, and premature baling of damp hay is the primary reason clover hay is sometimes mouldy.
From a nutritional standpoint, clovers and lucerne are very similar: higher in calcium and protein, and more calorie-dense than grass hays. Palatability is usually good as horses are inclined to love the taste of clover and eat it well.
Grass Hays
Common grasses sown include phalaris, fescue, cocksfoot and ryegrass. Kikuyu grass and other tropical grasses are popular in coastal areas but calcium supplementation needs to be given if these are the predominant species as they contain oxolates that bind calcium, rendering it unavailable for absorption. Tropical grasses mixed with ryegrass and clover or lucerne would be fine.
A special category of grasses are cereal hays. These hays are made from leaves, stems, and grains of oat, barley, and wheat plants. A good quality cereal hay is harvested when the grain is immature (soft dough stage) and the leaves and stems are still green, and therefore higher in digestible nutrients. If the cereal hay is harvested after the grain is removed, it is no longer considered hay but straw.
Oat hay is the most common cereal hay fed, and if harvested at the right time, it is quite palatable to horses.
Crandell uses the same process of evaluating grass hays as she does for legumes. To determine the type of grass, seed heads are the most telling, though blade characteristics are also useful.
Distinguishing hay types is important, if only from the standpoint of purchasing the appropriate hay. Generally, though, a mix of grasses in a hay is more common than any pure single-species hay so knowing where ti cam from can be helpful. As far as physical characteristics, Crandell assesses colour to determine how the hay was harvested. An overall brownish tinge could mean the hay was baled too wet and went through a caramelizing stage. Cereal hays should be light green in colour; a yellow, straw-like colour would indicate that the hay was harvested too late and will be of lower nutritional value.
She then estimates plant maturity. "Maturity is judged by the number and age of the seed heads, ratio of leaves and stalks, colour, and texture. I grab a handful or two to get an idea of the hay's texture. Early-maturity hays are softer to the touch than late-maturity ones."
As with legumes, Crandell checks for dust and unusual odour indicative of mould.
Mixed Hays
The term mixed hay can be an ambiguous one, which makes clarification essential. Mixed grass hays usually include a medley of grasses, some grown specifically for hay intended for horses and others not, while grass/legume mixes such as grass/lucerne, and rye/clover are also common.
Mixing grasses with a legume has two notable benefits. The first involves improvement of the land. Legumes add nitrogen to the soil, so growing legumes with grasses can cut down on fertilizer needs and growing costs. The other advantage involves palatability, as adding a legume to a grass can increase sweetness and consumption. Introduction of a legume also improves the quality by increasing energy, protein, and calcium.
Some horse owners prefer grass/legume mixes over pure legume because a mixture more or less averages the content of certain key nutrients to make it appropriate for different classes of horses. A practical advantage occurs as well: when grasses and legumes are grown together it is more difficult for horses to pick out the tasty portions, as they could if fed a flake of legume and a flake of grass.
Understanding the ins and outs of hay selection is an important aspect of horse ownership. The true test of hay quality rests with the horses, though, and if they offer up their approval by consuming it readily, selection was a success.
By Kentucky Equine Research - Last updated 16 November 2013
