Feeding Through the Ages: Understanding Your Horse’s Nutritional Needs Through Life’s Stages

Whether your horse is a growing youngster, an active athlete, or an aged companion, all horses share certain nutritional requirements. However, an individual horse’s nutritional needs will be further influenced by genetics, age, workload, and access to grazing, making it important for managers to consider many variables when crafting a ration.

Unfortunately, it is often the case that horses are fed “a scoop of this, a scoop of that” based on convenience or hearsay rather than scientific fact. According to Tigger Montague, owner, founder, and formulator for BioStar US in Gordonsville, Va., this is a mistake.

“We currently don’t feed to the caloric needs of horses,” says Montague. “It is incredible to me what an epidemic of overweight horses we have, and how many metabolic horses.”

Not only is feeding horses in a piecemeal approach hazardous to their health, but it can also be hard on the wallet.

“When we blindly buy a bag of concentrate because a trainer told us to or there’s a pretty picture on it that we want our horse to look like, then we waste money,” explains Dr. Tania Cubitt of Performance Horse Nutrition, an Idaho-based consulting company that advises for Poulin Grain’s equine line. “If you work with a professional, get the hay tested, and then put the results in a ration balancing program, you will feed a concentrate to complement what you’re not getting out of your forage.”

General Guidelines

When nutritionists craft their feeding recommendations for horses, they ask a series of important questions. Is this horse still growing, mature, or aging? Is this a high-performance animal or a weekend warrior? What sport or discipline is this horse training for, and what does that sport demand of him? How is the horse’s dentition? Is the horse gaining muscle, maintaining muscle, or losing muscle? 

“I think there isn’t a whole lot of change [in a horse’s nutritive needs] from two to 20,” says Cubitt. “It’s like a bell curve. At the beginning and the end, they have elevated requirements. Both [younger and older horses] need more concentrated nutrients to meet the requirements they have.”

All horses should have access to clean, freshwater (cool in summer, warmed in winter) to fully and safely process their ration. And all horses should have a ration that begins with high-quality forage, which should make up a minimum of 50% of the horse’s total diet.

“It’s all about feeding enough fiber,” says Cubitt. “In the Northeast, where there are at least five months a year where horses are primarily reliant on hay, I recommend storing a little over one ton per horse. If you can’t store or pay for that much all at once, you can use things like hay pellets or forage extenders to help.”

Though all horses should be fed a diet based on forage, depending on where your horse lives, their dentition, and their genetics, the form and quantity of forage will vary. On average, a horse should eat between 1.5 to 2.5% of his body weight in forage per day; this translates to 15 to 25 pounds! 

“I define ‘good quality’ forage as what is most appropriate for your horse,” says Cubitt. “Is it alfalfa? An orchard grass? A local grass mix? It all depends on your horse. Small differences in forage can have a big impact because you are feeding so much of it.”

Where your hay is grown will influence the nutrition it provides. For hay grown in the Northeast, experts report seeing consistent changes in quality over the past decade. In general, non-structural carbohydrates (sugars) are increasing and protein, phosphorus, and vitamin E are all decreasing. Most northern-grown hay is chronically deficient in copper, zinc, and selenium. Knowing what is (or is not) in the hay gives nutritionists a baseline to use in choosing the perfect concentrate to complement it.

Planning a balanced ration should start with a hay analysis. While this could prove difficult in a facility receiving loads every month if hay is purchased every six to 12 months, investing in an analysis (usually at a cost of around $30) will pay dividends.

“The only thing I can guarantee is that all horses need fiber, and then we ask a bunch of questions to decide what’s next,” says Cubitt. “Not knowing what you’re getting out of your forage—that is where a lot of people fail.”

Protein

You may remember from high school biology that proteins, made up of chains of amino acids, are the “building blocks of life.” Having sufficient high-quality protein is essential for basic life functions to be carried out, for young horses to grow, and for athletes to build muscle. But protein fed above the horse’s needs cannot be stored in the body; instead, it is excreted in the urine, and horses fed high protein diets unnecessarily may consume excessive amounts of water and have saturated stalls as a result.

“The protein needs of young horses all the way to seniors are not that radically different,” says Montague. “I think protein levels need to stay fairly consistent throughout the horse’s life. But the higher the level of work they do, the more protein they need.”

A young, growing horse may require a diet that is between 14 and 15% protein. But as they mature, their needs decline slightly and many horses can maintain good condition with 12% protein. As horses enter their senior years, protein needs may change yet again.

“The senior horse can become the most difficult of the stages of the horse to maintain muscle,” says Montague. “Once you lose the muscle with a senior horse, it takes a long time to rebuild it.”

However, Cubitt cautions against over-supplementing protein in an older animal. 

“It is one of the biggest pitfalls people fall into with the older horse,” says Cubitt. “We know protein is important for building muscle, so if the horse is losing muscle, we think he must need protein. But as a function of aging, the horse starts to lose topline, or they are not riding him as much because he’s older, or the horse has Cushing’s, a symptom of which is losing muscle tone. It is important to consider other variables.”

Energy Sources: Fat and Carbohydrates

Grab any box at the grocery store, and the label will reveal the total number of calories per serving, which helps to measure the energy value of the food. But for animal feed, listing calories or digestible energy (DE), which is the actual amount of usable energy, is not required by the American Association of Feed Control Officers (AAFCO). 

“Digestible energy is a calculated value, based on the protein, ash, and fiber in the feed,” says Cubitt. “There are several equations that are used to calculate DE, and companies will use the one that best highlights their feed.”

To ensure that horses receive the correct amount of energy from feed, managers should rely on the feeding recommendations listed on the product packaging by the manufacturer. These recommendations are calculated by equine nutritionists like Cubitt, who consider the product’s DE, the nutritional composition of average hay in a given region, and the nutrient guidelines set by scientists at the National Research Council. 

For many years, carbohydrates (sugars and starches) were considered the best source of fuel for horses. Many horses with access to pasture or fed high-quality hay can more than meet their energy needs through the sugars and starches these feeds provide. But for easy keepers or horses with metabolic conditions such as PSSM, Equine Metabolic Syndrome, or Cushing’s, too much sugar and starch can be deadly. For horses in higher levels of work, the “rapid burn” effect of carbohydrates may not sustain them through intense training or competition. The results of your hay analysis provide critical detail as to the amount of non-structural carbohydrate (NSC) your horse is receiving.

“If you find the NSC in your hay is high, and I would go no higher than 10%, you will have to soak your hay, especially if dealing with metabolic horses,” says Montague. “Hay needs to be soaked at least 30 minutes in cold water to remove the sugars. This can be a really difficult challenge in many barns, especially in winter.”

Increasingly, fat is being used as the primary energy source in a horse’s diet. Compared to carbohydrates, fat has as much as 2.5 times the level of energy and is often a safer source of fuel for horses sensitive to sugars and starches. But the level of fat in the diet must suit the amount and type of work the horse is doing.

“You can pretty much break it down by whether you want the horse to go fast or slow,” says Cubitt. “If the horse needs to go fast, he needs to engage the energy pathways that work those fast-twitch muscles, and that’s sugars and starches, that’s carbohydrates. If we are going to do more calm, long, slow exercise—that utilizes fats, or voluble fatty acids from fiber, as your energy source.”

Horses that tend to be harder keepers, like some Thoroughbreds or older horses, may do best on a higher fat diet.

“I like to be in the 10% area for fats, particularly with performance horses,” says Montague. “But for some warmbloods, if you add more fat, especially if it is a long-chain fatty acid like soy, vegetable, or corn oil, it goes right to the gut.”

If adding supplemental fat to the ration, Montague recommends avoiding heat-processed oils (like soy, vegetable, and corn) in favor of cold-pressed oils such as camelina, flaxseed, hemp seed, and most coconut oils.

“Camelina oil, which is also known as false flax, has the ideal ratio of Omega 3, 6, and 9 and has naturally occurring vitamin E,” says Montague. “Hemp seed oil is great because it is really high in gamma-linolenic acid (GLA). GLA works as a prostaglandin regulator, which is responsible for regulating inflammation in the body.”

Vitamins and Minerals

Vitamins and minerals play vital roles in keeping our horses healthy, happy, and sound. Certain vitamins—like C, D, and the B complex—can be produced within the horse’s body to some degree. But other vitamins and all minerals must be ingested, ideally in a bioavailable form that the equine body can easily process. Hay grown on poor soil or in regions with known deficiencies will be lacking in required minerals. This is especially unfortunate because minerals ingested by the horse through forage have been made bioavailable by the plant.

 “When a plant like a timothy grass or orchard grass is up-taking minerals from the soil, they are just rock ions,” says Montague. “The plants can’t use them in that form. What the plant does is frees amino acids and binds them to the mineral, and that mineral becomes bioavailable. This is a process called chelation.”

Chelated minerals may be highly bioavailable, but they are also expensive. Instead, many grain manufacturers use forms like calcium carbonate or magnesium oxide in their feeds. Like plants, the horse must first bind amino acids (protein) to the mineral to make use of it in his body. Minerals listed as proteinates or chelates will be more bioavailable to the horse.

“The bioavailability of inorganic minerals like oxides or carbonates is 8 to 10%,” says Montague. “For a proteinate, the bioavailability is 65 to 70%.”

Certain vitamins and minerals must be kept balanced in relation to each other. For example, a horse should always have at least twice as much calcium as phosphorus. In a young horse, that ratio may be increased to three or four parts calcium to one part phosphorus. Most feeds provide magnesium at one-third the amount of calcium.

“I personally like to keep the calcium/phosphorus/magnesium ratio pretty consistent throughout the life cycle,” says Montague. “We run into trouble by trying to just add one thing to balance it, especially minerals because they are all so related. That’s where owners get into trouble.”

Most commercial grains (and supplements) are produced with the goal of providing horses the optimal nutrition based on the best available science. But this requires consumers to feed the correct product in its recommended quantity.

“The most frequently misused feed is senior feed,” says Cubitt, who notes that senior feed is geared toward horses with poor dentition that cannot properly chew hay. “If you look at the guaranteed analysis, the senior feed is really high in fiber and is usually pelleted so you can wet it.”

Senior feeds are meant to be fed at the rate of 8 to 15 pounds per day, spread out across several meals, as they are intended to replace fiber for horses that cannot chew long-stemmed hay.

“[Senior feed] is not very concentrated,” says Cubitt. “It is quite diluted in vitamins and minerals because he’s eating such a large quantity. If someone with a performance horse feeds senior feed at just one to two pounds a day, you’re only feeding about 20% of the vitamin and mineral requirement.”

On the other extreme, ration balancers are a highly concentrated source of supplemental vitamins and minerals, meant to be fed in small quantities to complement a fiber source. Ration balancers are excellent sources of supplemental nutrition for easy keepers and metabolic horses, or even to top-dress the ration of a young, growing horse.

Final Thoughts

Experts emphasize that it is essential to feed each animal as an individual and according to the manufacturer’s recommendations.

“I get that it’s complicated, but if you have more than one horse, they may need different things, and we have to feed horses that way,” says Montague. “Not just as a basic species, equine.”

Always base a horse’s ration on forage.

“The bottom line is it comes down to the forage you have available,” says Cubitt, “that makes or breaks the diet.”

 

By Christina Keim