Q: I have a 5-year-old gelding who is not in work. He is on a concentrate feed now, but I’m considering switching him to a forage-focused diet. Would a diet of hay cubes (or pellets) and hay (and pasture when it’s available) sustain him, or does he need some type of concentrate to meet his nutritional requirements?  -via email

A: A forage-focused diet is a great option for feeding most horses; however, forage alone will not provide horses with adequate vitamins and minerals, so they do need some form of ration balancer or vitamin/mineral supplement to meet their nutritional requirements.

Obtaining a hay analysis is the critical first step when considering a change in your gelding’s diet. Your hay analysis will provide important information for choosing which supplemental product he needs. For a mature horse that is not in work, quality hay will likely meet his protein and energy requirements so your analysis will help you determine if your hay has adequate crude protein content.

About 8-10% crude protein will meet the requirement for most adult horses that are at maintenance level (not in work). The acid detergent fiber (ADF) and neutral detergent fiber (NDF) values provide insight into how digestible the forage is. As these values increase, the level of digestibility decreases and the amount of indigestible fiber increases—below 45% is ideal for ADF, and below 65% is best for NDF.

Digestible energy content of hay varies depending on the plant maturity and species of grasses/legumes in it. The amount of digestible energy a horse needs to maintain a healthy body weight can vary greatly depending on factors such as genetics. If your gelding is currently on a concentrate feed and doing well, it might be worth considering the digestible energy he is getting from that feed. This will depend on the product, as well as the amount he is being fed, but he might need additional energy from alfalfa cubes, or even a fat source such as flax oil, to maintain a healthy body condition when transitioned off the concentrate.

The hay analysis also provides information about mineral content, fat, starch, sugars, and moisture, all of which is important. For example, if your hay is high in moisture content (>15%) mold development is a safety concern, but if the moisture is too low (<6%), your hay might have excessive nutrient loss due to leaf brittleness. Overall, hay is almost always most of a horse’s diet so, to curate a balanced diet, you must know the nutritional value of the forage. If you have questions about the analysis results, reach out to an equine nutritionist.  

After interpreting your hay analysis results, if the hay provides adequate protein and energy you can opt for a vitamin/mineral ration balancer. Oftentimes these products do not tend to be palatable enough on their own, so you might need to mix them with a small amount of soaked hay cubes.

However, if the hay does not provide adequate protein you will need to feed a ration balancer that supplies protein as well. You’ll need to feed a greater amount of these products than the vitamin/mineral supplements but still much less than you would a concentrate, which is designed to provide additional carbohydrates and fats as well.

Choosing a quality balancer for horses on a forage-focused diet is important because hay is known to be deficient in nutrients such as vitamin E. If you remove the concentrate from your gelding’s diet and add hay cubes or pellets instead, there would be both vitamin and mineral deficiencies present in the diet that could lead to a variety of health issues and deficiency symptoms.

There are two primary ways to evaluate the nutritional content of pasture. You can take a sample and send it to a lab, but it can be challenging to collect an accurate sample and the nutritional content of pasture is continually changing. The nutritional content of pasture will depend on a plethora of factors such as the plant species present, soil health, time of year, pasture management, and weather. When comparing pasture to hay, pasture will be more robust in providing the many vitamins such as vitamin E, but you will still need to be supplementing a source of minerals.

If you are maintaining your horse on pasture, take the time to learn about pasture health, and optimal pasture management. Pasture can be a great option in the summer months for your horse’s primary forage source; however, when pasture is poorly managed, for example, not fertilized or is over-grazed, it can negatively impact the nutritional quality.

Whether you need to simply add a vitamin/mineral supplement, a ration balancer that also supplies protein, or a concentrate that provides additional calories, your decision will depend on the information your hay analysis provides. Horses, overall, have evolved to consume a forage-focused diet, so a diet high in fiber is often a good choice. However, because hay does not meet a horse’s vitamin and mineral requirements, a supplemental source of these nutrients is necessary to create a balanced diet.

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