GETTING ENOUGH HAY?

There’s no need to guess. In less than five minutes you can calculate your horse’s minimum hay requirement.

It’s probably not news to you that horses are herbivores with digestive systems designed for grazing around 18 hours a day. Or that the foundation of an ideal equine diet is high-fiber forage, such as pasture and hay. But making practical use of that knowledge can seem complicated. Thankfully, it’s not all that difficult to do.

But first, here’s a quick refresher on why feeding your horse enough hay is important to his health and well-being:

• Hay provides the fiber necessary for optimal digestive system function, reducing the risk of colic and other gastrointestinal problems.

• Hay is a good source of energy, protein, vitamins and minerals at varying levels, depending on forage species.

• Hay encourages healthy hindgut microflora vital to fermentation and digestion.

• Hay consumption increases the horse’s chewing rate, reducing the risk of cribbing and other stereotypic behaviors. Increased chewing also encourages saliva production, which in turn helps to buffer the acid produced in the stomach, reducing the risk gastric ulcers.

Despite these benefits, many owners worry that feeding too much hay can adversely affect performance. But research has shown that this is not true; in fact, studies suggest that high-energy fibrous feeds may even adequately support elevated nutritional requirements.

Another worry is that hay has potential to increase a horse’s bodyweight due to the water-absorbing capacity of fiber. However, strategic feeding and a short period of dietary restriction prior to competition can mitigate that possibility.

So how much hay does your horse need? If he is kept on pasture and offered free-choice hay when grass isn’t growing, he’s going to consume enough forage on his own. For horses stabled even part of the day with limited access to pasture, however, you’ll want to calculate the minimum and adjust from there.

Before we begin, it’s important to understand two terms: “as fed basis,” which means the actual amount of hay you give the horse by weight (more about that later); and “dry matter” (DM), which is everything in hay except the water—the protein, carbohydrates, minerals, etc.—and defines the nutrient value of the forage. Ideally all hay would be sold with a basic analysis including DM. However, in practice, few horse owners receive a detailed analysis of the hay they purchase so we estimate that most hay is 90 percent DM. Haylage has a lower DM percentage because it contains more water, but it is not commonly fed to horses in the United States, so we won’t dwell on that.

Here are some general guidelines to consider when calculating hay rations:

• Horses at a healthy weight are ideally fed a minimum of 1.5 percent of their body weight in dry matter

(DM) per day. If the hay is of good nutritional value, some horses can do just fine on this ration alone, with no supplementation with grain.

• Horses in high intensity training need a minimum of 1.25 of their body weight in DM as hay. The remainder of the ration would be supplied as a grain concentrate.

• A weight-loss regimen for horses would provide less than 1 percent of their body weight in DM as forage. A ration balancer can be a good way to ensure that overweight horses get all the necessary nutrients with limited hay and grain. Likewise, a “slow feeder,” which extends the time it takes to eat a hay ration, can be beneficial because it preserves many of the physical and mental benefits of a hay-based diet.

So, let’s get to it. To calculate your horse’s minimum forage requirements, follow these three steps:

1. Estimate your horse’s body weight. There are several ways to do this, including using a weight tape or livestock scale.

2. Determine the minimum DM forage requirement of your horse, according to his body weight and workload.

3. Calculate the minimum amount of forage your horse needs for optimal health; To convert the amount on a dry matter basis to the amount as fed, divide the amount of forage on a dry matter basis by the dry matter percentage of the feedstuff.

For example, what is the minimum amount of hay that an 1,100-pound mare in good condition and medium work would need? Here are the steps:

1. 1,100-pounds 2. Calculate 1.5 percent of 1,100 to determine DM forage requirement.

(1,100 x .015 = 16.5)

3. Divide that DM requirement by 90 percent (the presumed DM in the hay unless otherwise known) to determine how much hay to feed. (16.5 /.90 = 18.33)

(continued from page 58)

grows locally, since it’s expensive to haul hay; in fact, the price of shipping can surpass the price of the hay itself.

Nonetheless, sometimes shipping hay is unavoidable. Not every region of the country has ideal conditions for producing high-quality hay. During rainy periods, it is difficult to dry hay enough to bale. Hay baled at moisture levels greater than 16 percent can become moldy, making it unsuitable for horses. In arid regions, farmers can simply turn off irrigation systems when it’s time to cut, rake and bale hay. In humid regions, however, hay may have to keep growing several weeks beyond optimum maturity until weather is dry enough for harvest.

Some farmers use preservatives, typically organic acids that are not harmful to horses, to inhibit mold in hay baled in less-than-optimal conditions. The main one used is propionic acid, which is also produced naturally by bacteria in the horse’s digestive system. These preservatives don’t change the texture of the hay, but may affect the smell and even taste, leading horses to eat less of it until they get used to it.

In very wet areas, many horse owners have alfalfa shipped in from more arid regions, simply because that hay is higher quality than what can be grown locally. Growers who cater to the horse market are good at putting up high-quality hay, but you’ll pay a premium price for it.

All of these factors can affect your choice of hay for your horse. “Here in Florida we often have to pay a lot for hay because at least half the cost is for shipping. I have found that even though it is more expensive, it is more important to select a hay that the horse is able to eat—consuming all the hay that you buy. Otherwise, you are really wasting your money,” says Downer.

Although we may refer to them by the single, simple term “hay,” these cultivated, dried forages are as varied as the horses who happily dine on them. Understanding this opens a world of hay options you may not have known existed and provides the opportunity to select the very best type for your horse.