Photo: Anne M. Eberhardt/The Horse
Feeding horses can be a daunting and time-consuming task, particularly if owners attempt to optimize and maximize their horse's diet by unnecessarily introducing concentrates, vitamins, or other supplements. But providing a complete diet does not have to be time-consuming or expensive.
Step 1: Stop!
Horses require six nutrients in their diet: water, carbohydrates, fats, protein, vitamins, and minerals. Except for most of the water requirements, almost all of a horse's remaining dietary requirements can be obtained from a single source: forage.
"Adult horses that are not involved in moderate to heavy work do not generally require grain," advises Eleanor Kellon, VMD, proprietor of Equine Nutrition Solutions in Pennsylvania.
In fact, Kellon suggests that many horses will maintain an appropriate body weight and obtain all necessary nutrients on pasture and free-choice hay alone.
The only exception to this rule is sodium. According to Equine Extension Specialist Carey Williams, PhD, from the Equine Science Center at Rutgers, The State University of New Jersey, all horses require plain white salt, regardless of their feeding regime. The salt can be offered either free-choice as a salt block or as 1-2 tablespoons top-dressed if the horse does not care for the licks.
A mineral block (widely known as the "red block") is not essential, required, or recommended for the majority of horses because the levels of minerals (other than sodium) in the block are not at the level required by horses.
"In addition, some horses may consume a 50-pound block in a matter of days, which could cause problems with the mineral balance of their system," explains Williams.
Step 2: Weigh your Hay
If owners wish to feed hay in a daily ration instead of free-choice, each horse requires approximately 1.5 to 2.5% of their body weight in hay per day. Therefore, an average 1,000-pound horse will eat approximately 20 pounds of hay on a daily basis. Since counting flakes or "eyeballing" hay is an unreliable estimate at best, the only way to know how much hay you are feeding is to weigh it.
Kellon recommends using a bathroom scale in the barn. Weigh yourself and then weigh yourself again holding the hay. Alternatively, an inexpensive fish scale can be easily used in any barn.
For horses that are on pasture and being fed a ration of hay each day, the amount of required hay to meet their daily energy requirements can still be determined easily. A horse on good-quality pasture 24 hours a day, seven days a week, will meet his full 2% body weight energy requirement. Therefore, if a horse is on pasture half of this time, one could assume that 1% of his body weight is required in hay, which is equivalent to approximately 10 pounds of hay for an average 1,000-pound horse. Similarly, if the horse is on pasture only one-quarter of the time, then 1.5% of his daily energy should be supplied as hay (i.e., 15 pounds of hay per day).
The only complicating factor is if the pasture is overgrazed. If the pasture is grazed down approximately 50%, then a horse on pasture full time is likely only receiving 50% of his daily energy requirement. In this situation, an additional 1% of his body weight in forage (or 10 pounds of hay for an average 1,000-pound horse) will be required. Horses turned out on a 50% grazed pasture half of their time will, therefore, only be eating one-quarter of their daily energy requirement and will need to be fed three-quarters of their energy requirement in supplemental hay--approximately 15 pounds of hay for an average 1,000-pound horse.
Some equine nutritionists would argue these estimations on grass consumption during turnout are oversimplified. While there are few studies on pasture intake, there are estimates that horses can eat 0.5-1kg (1.1-2.1 pounds) of pasture dry matter per hour when they are turned out. Good quality pasture is usually higher in calories and other nutrients than hay, so they will often eat more than 50% of their requirements during a half-day turnout.
Step 3: Evaluate Body Condition
The only way to determine if your horse is being fed enough (or too much) using the forage-only approach is to properly evaluate body condition.
"In my experience, many owners either overfeed their horses because they like their horses overweight, or they are not familiar with what a healthy weight looks like," explains Kellon.
Just like in human medicine, obesity in horses is detrimental. Overweight horses are unable to dissipate heat during strenuous or prolonged exercise, and they can become resistant to the effects of insulin. This, in turn, is thought to contribute to the development of laminitis. Further, overweight horses find infrequent work (e.g., the weekend ride) challenging due to the extra body weight they carry.
Kellon suggests a horse is considered overweight if:
- The ribs are difficult to feel even with firm digital pressure;
- There is a bulging, "cresty" neck;
- The withers are rounded and only the tip of the spinous processes are easily felt or they are covered in fat;
- The girth makes an indent in the horse's fat when tightened;
- The saddle makes an indent in the fat on the horse's back;
- The shoulder blade of the horse cannot be easily seen and is not distinguishable from the neck, shoulder, and body of the horse.
- The area surrounding the tailhead is bulging and feels soft, or;
- The inner thighs touch each other more than a quarter of the way down the inner thigh region when the horse is standing square.
Ideally, horses at an appropriate body weight have ribs and hip bones that are not visible, but they are easily felt.
Exceptions to the "Forage Only" Rule
Adult horses that typically require an additional source of calories to maintain an appropriate body condition are those with higher energy demands, such as competitive horses, broodmares, or the infamous "hard keepers." A horse might also lose condition if he has problems with teeth that require veterinary attention or if he's low in the pecking order in his herd situation and simply is not getting enough to eat. Horses falling into this latter category can be separated from the herd and fed an additional ration of hay each day.
Even if only poor-quality (not moldy) hay is available, the daily energy requirements for most horses can still be met to maintain an appropriate condition without the addition of concentrates. Williams advises that if only poor-quality hay is available, then a basic multivitamin/mineral supplement should be fed to the horse on a daily basis.
For owners uncomfortable with feeding poor-quality hay or if hay is either prohibitively expensive or unavailable, then forage substitutes such as beet pulp without molasses, hay cubes, pellets, or bagged hay chaff can be considered. Again, switching to a forage substitute does not necessitate the addition of concentrates!
"For horses that are not maintaining their condition on their current diet, the first step is to simply increase the amount of forage," suggests Williams. Increasing the amount of forage by 2-5 pounds per day gradually over the course of two to three weeks may be sufficient, assuming the horse is cleaning up his hay. If the horse is losing condition and not cleaning up his hay, then an additional source of energy will be required and concentrates should be considered.
How to Use Concentrates
The first step in adding concentrates to a horse's diet is to visit a local feed store to determine what kinds and brands of products are available. For average adult horses, a basic pelleted feed or sweet feed (i.e., concentrates mixed with molasses to improve palatability) containing 10-12% crude protein and 3-10% fat is sufficient.
"The most important consideration when introducing a concentrated food is to keep feeding the exact same amount of forage and increase the amount of concentrate extremely slowly, which necessitates weighing the concentrate," emphasizes Williams.
She recommends starting with 1 pound of concentrate per day, divided into two or three feedings. The amount of concentrate fed can be increased by a half-pound every two to three days. No more than 6-8 pounds of concentrate should be fed per horse per day, and definitely no more than 3-5 pounds at any single feeding.
Kellon advises that if the expected results are not achieved after adding concentrates according to the manufacturer's recommendations, the owner should consult his or her veterinarian.
One additional product worth mentioning is the complete feed. Complete feeds are pelleted or extruded food products that contain forage, protein, oils, vitamins, and minerals. While complete feeds contain all of the required energy and essential nutrients, horses fed complete feeds consume their ration very quickly, leaving the remainder of the day with nothing to do.
"Horses are grazers by nature and normally spend the majority of their day eating," explains Williams. Feeding complete feeds, which are not intended to be supplemented with hay or other types of forage, leaves too much time for horses to partake in "other" activities, such as cribbing and additional destructive behaviors.
For product-specific questions, the best resources for owners are the manufacturers. Feed producers will be able to provide detailed information regarding energy, mineral content, etc., for their specific feeds.
For additional information, owners are encouraged to contact their local agriculture extension specialist. This is a state-funded agent who provides free services for farm and horse owners. Extension specialists provide feeding guidelines, information regarding toxic weeds, pasture management-related help, and they can assist owners in locating hay or suggest appropriate forage alternatives, among other services.
Extension specialists can be located by contacting the local county extension cooperative office by phone, or by searching the Internet (e.g., Google your state's name with "cooperative extension"). Some land-grant universities have online information available in addition to the assistance offered by the county extension personnel. Together these resources will help horse owners answer their most pressing questions about their horse's nutritional requirements.
About the Author
Stacey Oke, MSc, DVM, is a practicing veterinarian and freelance medical writer and editor. She is interested in both large and small animals, as well as complementary and alternative medicine. Since 2005, she's worked as a research consultant for nutritional supplement companies, assisted physicians and veterinarians in publishing research articles and textbooks, and written for a number of educational magazines and websites.