Tips for forage-only diets, plus common misunderstandings

Tips for forage-only diets, plus common misunderstandings

Posted by Bluebonnet Feeds on Mar 14th 2023

Forage is the most important part of your horse’s diet. Quality hay not only provides the majority of nutrients essential to your horse’s health, but also promotes more natural grazing behavior and digestive processes. In other words, when eating hay, your horse’s body is working as it was designed - to be out in a large field, grazing for most of the day.

4 easy tips for feeding a forage-only diet successfully:

  1. Forage should be the foundation of your horse’s diet, fed at around 1.5-2% of their body weight1. The average 1,000 lb horse, at maintenance, should eat 15 to 20 lbs per day.
  2. Provide a quality diet balancer to cover essential vitamins & minerals.
  3. Test your forage to make sure your horse is getting enough calories, understand macro and micro-nutrient composition, and ensure your hay is high in digestible fiber. Studies show that forage cut at an early plant maturity stage provides high fiber digestibility and energy content, while late-cut forage does not8.
  4. Use a hay net to encourage all-day grazing, and slow down easy-keepers.

Is a forage-only diet right for my horse?

Many of today’s horses can thrive on a forage-based diet, as long as we manage the critical details. At the same time, performance horses, and those with increased energy requirements or special needs, often need some additional support.

We’re all trying to do the best for our horses, but nutritional information gets complicated and confusing very easily.

5 most common misunderstandings about forage-only diets:

  1. Forage & hay has everything my horse needs.

    While a forage-only diet comes very close to meeting the needs of a horse in maintenance (one that is not being ridden, bred, or growing), all forage lacks adequate trace minerals. There is no horse that can perform or reproduce at OPTIMUM levels without trace mineral supplementation1.

    Adequate vitamins would also be a concern. From the moment you cut hay, the vitamins begin to degrade 2. The more time between cutting and feeding of hay, the more likely it is to fall short of the vitamins your horse needs.
    Horses with higher nutritional requirements, may even struggle to eat enough hay to meet their energy and/or micronutrient needs.

  2. Hay pellets and cubes can provide the benefits of a forage-only diet.

    While cubes and pellets are often an excellent forage alternative, we prefer adding these as supplemental to long stem forage.

    Most of the benefits from a forage-only diet come from the digestion of long-stem forage, like hay or pasture grass. More time spent “grazing” and slower processing through the digestive tract, are just a couple of the direct benefits for your horse6. Whenever possible, buy quality, long-stem hay to maximize that “chew-time”.

  3. All horses should have 24/7 access to forage.

    Ideally, yes! Horses are designed to spend over half of their day eating or, rather, grazing.

    Though there are many instances where this becomes a challenge such as obesity, metabolic conditions, or senior horses who may be losing teeth. If your horse has good chompers, we recommend using hay bags and slow feeders as much as possible. This will also help manage weight and metabolic conditions. If your horse is struggling to chew from aging teeth, they’ll likely need calories from a quality senior feed.

  4. Forage-only diets decrease the risks for health complications, like intestinal stones or ulcers.

    The most common dietary contributor to Enteroliths is a high magnesium diet, such as feeding alfalfa-only diets7. Especially when combined with the ingestion of something foreign.

    It is true that multiple studies show that providing constant access to long-stem forage significantly reduces the occurrence of gastric ulcers8. Daily turnout in a grassy pasture or with a hay bag/slow feeder, is one of the best ways to help ulcer-prone horses.

    It’s important to note, however, that ulcers aren’t directly caused by concentrated feeds. Instead, research indicates that it’s the combination of large meals without access to forage in between, lack of long-stem forage in general, and other stress factors.

  5. A hair/mane mineral analysis will tell me if my horse has a deficiency.

    Hair Analysis is NOT a reliable way to find deficiencies3 and has little value in assessing nutritional health4. The results of hair analysis can be different during different seasons of the year. Plus, things like hair coat color5 and dust, can also affect the results of hair analysis.

    Not to mention, that the hair that you look at was formed weeks or months in the past and will not tell today’s story. Check out Feed Room Chemist Podcast Episode #109 for more.

3 times to provide a quality, fortified feed:

  1. Horses that are being ridden, breeding, or still growing have higher nutritional requirements. Performance horses, broodmares and growing horses need additional calories, more amino acids, and extra vitamins and minerals. All of which are critical to developing strong muscle and healthy bones, joints and organs.

  2. Senior horses, or those with degrading teeth, may struggle to chew forage. Thanks to great care and nutrition, our horses are living longer than ever (and we’ll take all the time we can get with our beloved 4-legged family members!). At the same time, many horse’s teeth won’t last through their later years. Today’s older horses may start to struggle to chew hay and forage and will require additional calories from a concentrate. Look for a fully-fortified feed, designed for seniors with soft, easy-to-chew pellets.

  3. Horses who can’t get enough calories.Some horses eat slowly while others, like broodmares in the 3rd trimester or lactating, simply cannot eat enough hay in a day to cover their needs. For these horses, incorporating a concentrated feed can close the gap. Look for a low-starch feed that’s high in digestible fiber and healthy fats, as well as covers essential vitamins and minerals.

When doing your own research, try also searching Google Scholar to look for reputable and unbiased scientific articles.

You can also work with an equine nutritionist to design the right, balanced diet for your horse.

Referenced research

1 - National Research Council (NRC). Nutrient Requirements of Horses, 6th ed. Washington, DC: National Academy Press, 2007

2 - BA. Palmonari, M. Fustini, G. Canestrari, E. Grilli, A. Formigoni, Influence of maturity on alfalfa hay nutritional fractions and indigestible fiber content, Journal of Dairy Science, Volume 97, Issue 12, 2014,Pages 7729-7734, ISSN 0022-0302,

3 - Seidel S, Kreutzer R, Smith D, McNeel S, Gilliss D. Assessment of commercial laboratories performing hair mineral analysis. JAMA. 2001 Jan 3;285(1):67-72. doi: 10.1001/jama.285.1.67. PMID: 11150111. Hintz, H.. (2001). Hair analysis as an indicator of nutritional status. Journal of Equine Veterinary Science - J EQUINE VET SCI. 21. 10.1016/S0737-0806(01)70122-0.

4 - Cape L, Hintz HF: Influence of month, color, age, corticosteroids and dietary molybdenum on mineral concentration of equine hair. Am J Vet Res 1982;43(7):1131-1136.

5 - Ralston S. VMD, Ph.D., dACVN: Forage Substitutes for Horses, Department of Animal Science, School of Environmental and Biological Sciences, Rutgers University, Fact Sheet 073 – Reviewed 2004

6 - Ashaki A. Rouff, George A. Lager, Dayana Arrue, John Jaynes, Trace elements in struvite equine enteroliths: Concentration, speciation and influence of diet, Journal of Trace Elements in Medicine and Biology, Volume 45, 2018, Pages 23-30,, ISSN 0946-672X,

7 - Luthersson N, Ýr Þorgrímsdóttir Ú, Harris PA, Parkins T, Bennet ED. Effect of moving from being extensively managed out in pasture into training on the incidence of equine gastric ulcer syndrome in Icelandic horses. J Am Vet Med Assoc. 2022 Sep 28;260(S3):S102-S110. doi: 10.2460/javma.22.06.0263. PMID: 36149938.

8 - Ringmark S, Revold T, Jansson A. Effects of training distance on feed intake, growth, body condition and muscle glycogen content in young Standardbred horses fed a forage-only diet. Animal. 2017 Oct;11(10):1718-1726. doi: 10.1017/S1751731117000593. Epub 2017 Apr 3. PMID: 28367770.