Why Hay is Not Enough

While an all forage diet can be appropriate for some mature horses, mainly those not involved in any energy expenditure activities, most require some sort of additional feed. Because we have confined horses and then use them for many different types of activities, it is generally accepted that any working horse will need additional nutrients on top of their forage year-round to maintain health and an acceptable body condition.

Even non-working horses need additional feed to meet non-energy nutritional requirements. As mentioned in our Pasture Management article, nutrient quality of forage will vary by the plants themselves, what stage of growth they are in, and on the soil the pasture is grown on. Thus, forages themselves may be deficient in certain nutrients, which is why it is recommended to supplement the horse’s diet with a sufficient concentrate to ensure optimal nutrition. To learn more about assessing what nutrients forages provide, our Total Diet of the Horse article goes more in depth.

To determine what additional nutrients are needed beyond forage, you must first ask what the horse’s daily activity is like. The amount of exercise or work a horse does each day will heavily influence their dietary requirements. The following categories break down the levels of exercise and these horses will almost always need additional nutrients in addition to their forage.

  • Light activity is generally 1-3 hours of exercise per week of walking, trotting and rarely cantering. Activities include recreational riding, occasional shows, or early levels of training.
  • Moderate activity is generally 3-5 hours of exercise per week of trotting, some cantering, and some instances of jumping, cutting or other work. Activities include recreational riding, ranch work, horses in a training program.
  • Heavy activity is generally 4-5 hours of exercise per week, with trotting, some cantering and galloping, jumping and other work. Activities include more intense ranch work, polo, frequent shows, eventing and race training.

As work intensity increases for a horse, nutrient requirements also increase. For horses not undergoing any work with a maintenance diet compared to horses undergoing various types of work, the following recommendations from Nutrient Requirements of Horses (NRC, 2007) for the total diet demonstrates how just some of these requirements change.

  • Maintenance diet per day includes: 8% crude protein, 0.91 Mcal/lb fed, 20 g calcium and 14 g phosphorus
  • Light activity diet per day includes: 10% crude protein, 1.1 Mcal/lb fed, 30 g calcium, 18 g phosphorus
  • Moderate activity diet per day includes: 10.5% crude protein, 1.2 Mcal/lb fed, 35 g calcium and 21 g phosphorus
  • Heavy activity diet per day includes: 11.5% crude protein, 1.3 Mcal/lb fed, 40 g calcium and 29 g phosphorus

It is often difficult to assess any mineral or vitamin deficiencies in horses. Energy deficient diets are usually the easiest to identify. This manifests itself in a horse losing weight and body condition. The Tribute® Equine Nutrition Wellness System is an excellent start on evaluating your animal and its current diet.

While it will not be discussed at length here, nutrient requirements for young, growing horses are much higher than mature horses. This is also true of broodmares and stallions in a breeding program. You can learn more by reading our Feeding the Weanling and Yearling article. You can also read our Feeding the Broodmare During Gestation and Feeding the Lactating Broodmare articles for more information.

Finally, Tribute® brand of feeds are expertly formulated to meet the nutritional requirements of your horse at any stage of training or life. For example, Essential K® is an excellent low non-structural (NSC) carbohydrate ration balancer that will help maintenance or even low activity horses reach their daily essential vitamin, trace mineral and amino acid requirements. Conversely, Kalm Ultra® is formulated for horses under heavy work due to its high fat content and highly digestible fiber inclusion, along with an optimal balance of essential amino acids, organic minerals, omega fatty acids, and antioxidants.

Since feeding situations are dynamic, we encourage you to reach out to us directly to develop a personalized feeding plan tailored to each of your horses.

Article By: Chris Mortensen, Ph.D.
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