The Grass is Not Always Greener

The word "horse" conjures up images of graceful, powerful animals roaming across miles of rolling hills, periodically stopping to graze on lush, green grass. In reality, such scenes are rare; these days, many horses live without grazing at all.

Equine nutritionist and veterinarian Susan Garlinghouse, DVM, MSc, of Wellington, Colo., says the reasons behind the non-grazing trend are largely circumstantial. "The limitation, in most cases, is not that a horse is unable to graze, but usually that safe pasture is not available, either because of more horses living in urban situations, or because what turnout is available has unsafe fencing or social structure," she says. "For example, turning out stallions together or into a group of mares with foals may not be possible. In desert areas, grass is not easily grown and maintained, so turnout provides exercise opportunities only."

Urban sprawl has contributed to a lack of suitable pasture. "More and more horses are reared and maintained around urban areas," says Paul Siciliano, PhD, a nutritionist and associate professor in the Department of Animal Sciences at Colorado State University. "Here in Colorado, there are certainly a number of three- and five-acre horse operations, but there is no water that goes with it. When you live somewhere where there is 14 inches of rain annually, there's not a lot of available pasture."

These circumstances aside, there are many conditions that keep horses from grazing normally. "Some horses have restrictions that render them physically unable to graze, such as those with chronically malformed dental occlusions as a result of congenital defects (including) parrot mouth or monkey mouth, or severe injury," Garlinghouse says. These afflictions differ from those associated with horses which have not received regular dental treatment.

Too Much Grass

For some horses, grazing on pasture can pose a health risk, especially for horses prone to laminitis. "There are some horses who shouldn't be allowed to graze, or whose grazing time should be strictly controlled," Garlinghouse notes. Research has indicated that lush, green grass can contain up to 20% soluble carbohydrates. "Thus, a horse grazing free-choice on lush spring grass may be consuming as much sugar as contained in a large grain meal, which can be a considerable risk factor in some horses."

"Certain horses that are overweight--particularly ponies--if they are put out on green grass are more prone to founder, especially in the spring," notes Rex A. Ewing, author of Beyond the Hay Days: Refreshingly Simple Horse Nutrition.

Garlinghouse suggests that owners of laminitis-prone horses restrict the animals' grazing patterns or cut grazing out of their diets altogether. She does, however, offer a bit of hope for horses in this situation: "There is some research now available from the UK suggesting that fructan content is a primary contributor in the incidence of laminitis in pasture-grazed horses. As fructan content is highest in 'stressed' pasture, such as pasture that is over-grazed or after a frost, it may be possible in the future to better predict which pastures are riskier for laminitis-prone horses." (See "Cutting Down on Carbs for Your Horses" on page 116 for more information.)

The grazing patterns of pregnant mares turned out on fescue pastures should be restricted as well. "Fescue contaminated with the endophyte Acremonium coenophialum produces reduced or absent milk production and placentitis in mares, with a subsequently higher incidence of dystocia, retained fetal tissues, and other complications," Garlinghouse explains. She adds that pastures planted with endophyte-free fescue can also pose a threat because they can become contaminated by infected fields nearby.

Another health problem that might be affected by pasture access is allergies. Some allergy sufferers might not fare too well on pasture, either--in some cases, summer heaves can be caused by pasture allergies. However, horses with respiratory problems due to dust would benefit from pasture. Consult your veterinarian if you believe your horse has allergies.

Keep in mind that heaves cases also suffer if left standing around in a dusty barn all day. Controlling dust is one way to lessen the severity of this condition, but horse owners also should address this issue during feeding. "Wetting or soaking the hay prior to feeding may help, as well as feeding non-hay alternatives such as soaked beet pulp or hay cubes," Garlinghouse suggests.

Wide Open Spaces

Sometimes, the pasture itself might not pose a health risk, but turning a horse out onto it could. Horses placed on stall rest as a result of an injury fall into this category, as do surgical patients.

"Post-colic surgical cases are normally kept off pasture for at least several days following recovery, if not longer, and orthopedic cases may require stall rest for weeks or months," Garlinghouse points out. "In the latter case, it's not the pasture which provides the risk factor, but simply the additional space and potential for re-injury. In these cases, some grazing may still be allowed on a lead, if hand-walking is allowed and if the handler is capable of fully controlling the horse."

Ensuring Enough Nutrition

Dennis Passa, owner and operator of The Feed Store in Richmond, Minn., advises owners not to overdo it when administering dietary supplements to augment nutrition from a diet lacking in pasture. Passa prefers to feed a grass hay diet with a commercial feed rather than add a lot of supplements to the diet. "It's already mixed up, it's a lot easier, and it's a lot cheaper," he says. "If you buy a good-quality feed and good-quality hay, you are going to be covered unless you have specific problems. Then, of course, you are going to have to supplement their diet. But this is the easiest and most economical way to do it in the long run."

If supplements are necessary, he recommends, "Pick a good supplement and a good feed, follow the directions, and stay with it. We run into a lot of situations where people are using a variety of supplements and they counteract other things. People end up increasing the amount of protein energy considerably with supplements."

Still, a good-quality pasture is the best food for horses--something that horse owners must consider when devising a feed program for those which don't graze. "It's difficult to provide a formula for all the nutrients and benefits of pasture, because nothing really replaces good, green grass," Garlinghouse admits. "Aside from the basic nutrients, grass is full of antioxidants, bioflavonoids, and isoflavonoids--supplements that can be purchased at a health food store at a considerable price. Good-quality hay is usually the best we can do, with additional supplements added as needed on an individual basis."

Siciliano cautions that if the pastures in your area are low in nutrients, the local hay will be similar. "Most of the trace minerals and other micro-nutrients, if they are low in the pasture, they are probably low in the hay, so horses on this type of pasture would require some supplementation," he says.

"You want to provide very good-quality forage, lots of protein, and lots of digestible energy," Ewing instructs. "One of the best things you can do is make sure your horse is parasite-free, and provide good, clean water at all times."

Conrad Boulton, DVM, of the Pilchuck Veterinary Hospital in Snohomish, Wash., notes that owners don't always know exactly what is being fed, and how much is being administered. A coffee can, he says, isn't an adequate measurement tool. "You may have an idea of what he is getting in terms of concentrates, but you have no idea what the bulk of his diet is. He may be getting two flakes of hay, but how much does the bale weigh? They vary all over the place," he says.

Behavior and Grazing

Generally, horses spend 70% of their time grazing, depending on the quality of the pasture, according to Garlinghouse. Those responsible for developing feeding programs for the non-grazing horse should bear this in mind. "Horses are naturally evolved and psychologically hard-wired to nibble their way through the day, and preventing them from doing so is an invitation to developing stable vices such as wood chewing, cribbing, kicking, pawing, and weaving," she says. "Supplying hay free-choice around the clock is always a good first step." She suggests that feeding large amounts of grass or grain hay, instead of smaller amounts of rich legume hay, might work out better for most horses.

Even with a set feeding schedule, hay should always be available. "Not only do we try to maximize the amount of forage in the diet, but we also should spread it out over the course of the day with a minimum of two feedings, possibly three," Siciliano instructs. "These feedings could happen once in the morning, once in the evening, and once before they go to bed, which serves as a nice time to check on the horses."

In removing horses from pasture, we alter their natural way of life. As a result, some behavioral and health-related issues can develop. "These problems tend to be associated more with a stall-bound environment, as opposed to absolute issues due to lack of grazing," declares Garlinghouse. Sheer boredom can produce habits such as chewing, kicking, and cribbing. These stable vices generally result in a damaged barn, but they have the potential to cause serious health conditions.

"Wood chewing and cribbing often cause uneven wear on the incisors, anxiety and boredom can increase incidence of colic, and some stalled horses will kick or paw to the point of causing solar hoof abscesses," Garlinghouse cautions. "Occasionally, a few horses develop the habit of incessant water-drinking, to the point of causing a kidney condition called medullary washout."

"These are related to the fact that they don't have their normal exercise routine and that their feeding patterns are altered," Boulton says. "If you took all of that away and ran them on pasture, it would reduce these problems a lot."

When this isn't possible, horse owners should keep a close eye on how the horse functions. "When you have a more sedentary lifestyle, you end up with some problems--you get a little too much gas, or too much (feedstuff) in there without enough water, and things tend to be a little sluggish as they move through the piping system," he says. A horse with good intestinal performance, in combination with a healthy diet and plenty of water, is better equipped to live without pasture grazing.

Some horse owners find ways of occupying stall-bound horses with various toys and feeding devices. "There are various schemes for making hay consumption a more laborious task for the horse," Garlinghouse notes. "One plan is to stuff hay inside several layers of hay netting, making the hay inside available just a few shreds at a time. I've also seen hay nets hung swinging almost out of the horse's reach outside the stall door, so that they have to play 'bobbing for apples' to get a bite."

Ancillary Problems

To avoid the problems that are often associated with non-grazing horses, owners should provide an adequate alternative to pasture grazing. Turning out on a dry lot and establishing a regular exercise routine helps keep weight down on the easy keeper.

Some overweight horses can be fitted with grazing muzzles--enabling them to be turned out on pasture. "Grazing muzzles are possible solutions for some horses that will tolerate them, as they slow down the rate of grazing while still allowing the benefits of exercise and social interaction," Garlinghouse continues, but she's not enthusiastic about using them on a long-term basis.

To ensure that horses low in the pecking order get enough nutrients in a pasture or dry lot situation, Ewing notes that a larger pasture might help; then more aggressive horses can't prevent others from eating.

The availability of quality feeds and supplements have enabled horse owners to help their horses adapt to pasture-free environments. However, most agree that nothing beats the real thing. Boulton emphasizes that owners who are able to supply pasture should remain educated about what is growing in their backyards. "It would be a big step toward putting a lot of veterinarians into lesser workloads if people who had horses and had pastures were knowledgeable about the grasses," he says.

Regardless of the reason your horse can't graze, turnout in general helps horses avoid health problems. "They have it better turned out," says Boulton. "If you can combine some kind of turnout with other horses so they may socialize, it's better."


Kathryn Watts, BS, director of research for Rocky Mountain Research and Consulting, has found that some hay isn't a safe diet for insulin-resistant horses (which are at risk for obesity and laminitis), and in fact some hays could be much worse than one might think. But she has had success with an easy, very inexpensive way to make hays safer.

Watts presented a poster on her research findings at the Second International Equine Conference on Laminitis and Diseases of the Foot, held in West Palm Beach, Fla., Nov. 10-11, 2003. Her focus was on the levels of water-soluble carbohydrates (sugars) in hay, which are powerfully affected by the weather conditions before hay is cut and while it dries.

"Sunny days combined with cold nights causes the sugars produced by photosynthesis during the day to accumulate when growth that occurs at night is restricted," says Watts. "Other factors that may increase water-soluble carbohydrates (WSC) in hay are drought stress, intense sunlight, nutrient deficiencies, high salt content of the soil, and very rapid drying of the hay. About the lowest-sugar hay you can get is hay that was rained on between cutting and baling."

Increased WSC, including the fructan that is often used to induce laminitis for research, is bad for horses which can't handle a rich diet. But how do you tell if your hay has too much sugar? Have it tested, says Watts--the look of hay is no indicator if its sugar content. Part of her poster included samples of various hay types from different areas of the United States. High-sugar hays included several different plants and different colors of hay; in other words, you couldn't select "good" or "bad" hay (in terms of sugar content) based on visual inspection.

Watts listed several high, medium, and low-sugar/fructan grasses common to horse pastures based on USDA forage research on reactions to cold stress. (For this list and more information on Watts' research, see article #4777 online.)

But how can you cut down on carbohydrates for your horse when the hay is already baled? The answer is simpler than you might think. Remember those WSC--water-soluble carbohydrates--discussed earlier? Water-soluble means they dissolve in water: "Simple sugars, disaccharides, and short-chain fructan are soluble in cold water, while the longer-chain fructans are soluble in hot water," says Watts. Her research found up to a 30.7% reduction in WSC content of hay after soaking. The plant species, its initial amount of WSC, and its maturity at cutting all can affect the WSC reduction potential, she said.

About the Author

Carolyn Heinze

Carolyn Heinze ( is a freelance writer/editor. She currently works from her pied à terre in Paris, France, where she continually dreams of convincing the French Republican Guard to let her have a go-round on one of its magnificent horses. One can dream, can't they?

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