Horse's Diet vs. Nutrition

If your horse develops a health issue, adding supplements or medications before checking the basics of digestion may not be the answer!

by Mary Ann Simonds

Horse with Hay

Horses living in well-managed pastures with a diverse mix of grasses and other plant material, free-choice salt, and fresh, clean water are likely getting what they need nutritionally. But horses living in confinement with limited plant matter, engaged in high-performance sports, or in a pasture with poor soils and non-palatable plants may need diet supplementation in order to achieve proper nutrient intake. With thousands of nutritional supplements available in the marketplace how do you know what your horse needs?

Blood and urine tests give you a good overview of your horse’s health, and your horse can also tell you what it needs—if you know what to look for and how to test. Your horse evolved as a free roaming, social herbivore, eating for up to 15–20 hours a day and often walking 20 or more miles daily. By walking all day and eating small bites of rough forage, the digestive system was constantly active. Modern horse keeping requiring horses to stand most of the day in a stall eating is “contra-natural” to the horse’s evolution

Benefits of “Free Choice”

Horses are opportunistic foragers and their diets in nature change according to habitat and seasons. They do have food preferences and will eat a variety of plants to meet their nutritional needs. Allowing your horse to have “free choice” vitamins and minerals[1] allows you to monitor its preferences and needs. A horse not familiar with selection or significantly out of balance will often try everything, but after a few days or a week will settle in on what it needs.

Allowing your horse to hand graze around the barn on non-sprayed and non-toxic weeds can also give you indicators of nutritional needs. Horses who may have ulcers, lack fiber, or are toxic will often seek woody or bitter plants. While horses may enjoy the taste of various plants, once they find something their bodies need, they remember where those plants are located and continue to seek them out.

If hand grazing is not possible, you can observe what your horse may gravitate to on the trail. Horses who never get to taste anything other than hay and grain will look for other plants to supplement their diet. Obtain a plant guide from your local United States Department of Agriculture’s (USDA) Agricultural Extension Office to determine safety of plants.

Importance of Teeth

It is critical to make sure your horse’s teeth are in good shape. Not all horses are gifted with perfect teeth. It is tempting to file down a horse’s teeth for routine maintenance, but remember, you may be impeding your horse’s ability to properly chew and break down plant material. In nature a horse will eat a variety of grasses, herbs, shrubs, trees, lichens, and even dirt, which can naturally wear down the teeth, but in domestic life teeth can wear down early in a horse’s life.

Healthy Digestion is Key

If something gets out of balance in the digestive track, ~~then~~ the whole body can develop symptoms of imbalance. Health issues such as anhydrosis or non-sweating, metabolic syndrome, tying up, ulcers, poor feet, or dull coat can all be tied back to improper digestion. Even behavioral issues such as spooking, getting quick over the jumps, worrying, bucking, rearing, or refusing to go forward, can be related to poor digestion. Try to maintain these key components: healthy forage and nutrients, good teeth, adequate saliva, clean water, proper pH, enzymes, healthy tissue in the stomach, small intestines and large intestines, happy microbes for fermentation, and correct motility and movement.

Value of Hay and Manure Tests

Conduct both hay and manure tests to evaluate how your horse is digesting. Most hay growers and feed stores will provide you an analysis of the hay or you can send your own sample into a lab, which offers a variety of analysis packages for hay and pastures. A basic analysis evaluates protein, fiber, carbohydrates, and minerals. Giving a horse too much of a certain vitamin or mineral can be just as detrimental as not enough. Learn more about any hay you purchase. Check the soils and make sure they are not toxic, as there are no laws governing growing hay on toxic soils. Look for hay not sprayed with weed killer or pesticides, or over-fertilized, because all of these can throw off your horse’s digestive ability.

In One End and Out the Other

If your horse is not digesting its hay properly, nutrient absorption will be poor. Adding a hoof supplement or any other supplement is likely not to help until proper digestion is established. Likewise, if your horse is not sweating, adding electrolytes without having an electrolyte analysis may just complicate the problem. Many health issues have simple fixes, but basic diet and nutritional evaluations are often overlooked as the underlying issues, particularly when the horse consumes good hay and respected supplements.

How to Check Manure for Hay Digestibility

Courtesy Mary Ann Simonds

Orchard Grass Hay

Dry Orchard Grass

Hay may look and smell wonderful and your horse enjoys the taste, but if the hay is too high in sugar, is inadequate in nutrients or has an imbalance in minerals, or has stems that are too tough, your horse will not be able to properly metabolize nutrients and use energy.

Courtesy Mary Ann Simonds

Timothy Hay

A simple twist test can help determine relative amount of moisture and digestibility. To determine if hay has toxins or too much fertilizer perform a quick soak test. Add a few handfuls of hay to a bucket of water and let sit for 15 to 20 minutes. Water will appear green to brown, but should smell a bit like green tea. If the water is black, has no smell or does not smell good, then it may have too much fertilizer or other improper additives.

Manure checking is essential to evaluate how your horse is digesting.

Mary Ann Simonds

Hay Test

Orchard Grass Hay manure in water test.

Ideally, the manure should not smell bad, have few small (1 inch or less) undigested plant stems and no long undigested material. The manure should be nicely formed and appear as spongy moist balls. An average horse with proper digestion will pass about 50 pounds of manure each day, spread out into eight to12 piles. Every horse is different, so tracking what goes in and what comes out is key to determining if your horse’s diet is meeting its nutritional requirements.

Courtesy of Mary Ann Simonds

Timothy Hay in Water

Testing horse's manure in water-Timothy Hay

Courtesy Mary Ann Simonds

Orchard Grass in Manure

Horse Manure only on Orchard Grass Hay

Courtesy of Mary Ann Simonds

Horse Manure-on Timothy

Manure of a horse only on Timothy Hay

Checklist for a Balanced Diet

1. Monitor Horse Weight — Using a scale is best, but tape method can estimate.

2. Evaluate Hay - Sample Analysis — “As Sampled – with water” and “Dry Matter”- protein, digestible energy, ethanol soluble carbohydrates (sugars), starch, lignan, fiber, calcium, phosphorous, magnesium, potassium, sodium, iron, zinc, copper, manganese, molybdenum.

3. Monitor Feed and Water Intake Daily —

Although food and water intake is dependent on environmental conditions, level of activity, type of feed, and the physiology of the horse, an average 1100-pound horse with limited exercise in cool weather will eat 18–22 pounds of dry matter forage and drink between eight to12 gallons of water per day. Keep track of your horse’s consumption in various seasons to learn what is “normal” for your horse. Weigh your forage to keep track of amounts.

3. Check Manure — Check amount, color, smell, consistency, and form. Break apart and check, then add a clump or two in a cup and fill with water and stir. Let sit for 20 minutes or more and stir again. What is floating versus what is holding water? Fiber should hold water and particles should look evenly digested.

4. Monitor Salt Intake —Weigh your salt block or loose salt daily. Correlate this to temperature and level of exercise.

5. Allow free choice selection of vitamins and minerals if possible and monitor uptake.

Horses can be as different as humans; just because most horses do well on a particular feeding program, does not mean your horse will do well too. Observing how your horse ingests and digests forage will save you money in the long run and prevent many digestive imbalances from becoming serious health issues.