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Pros and Cons of Grazing

Pros and Cons of Grazing


Horses naturally meet their nutritional needs through grazing. It is possible to provide a balanced nutritional diet for horses that are not allowed to graze, but there are several advantages to providing good quality pastures for horses.

Good pastures provide one of the best and least-expensive means of feeding horses. The horse’s digestive tract needs adequate fiber to function properly. Pasture forages provide fiber, as well as protein, minerals and vitamins.

Horses appear to be healthier when kept outside on pasture with adequate shelter because they get sunshine, fresh air and exercise. Most horses kept on pasture also have a better disposition than horses that are kept in stalls all of the time.

Grazing also may improve reproduction. Mares placed on spring pasture have been shown to ovulate up to seven days earlier than mares of similar age that are kept on dry lots and fed hay. New Jersey horse standing behind a fence in a snowy pasture

Without proper management, however, there can be drawbacks to grazing both for horses and the environment. For example, horses can be malnourished in deep, green forage. Extremely lush pastures containing more than 85 percent water can be too wet and too low in fiber for good nutrition and dry-matter intake. Providing too much water and too little nutritional value, plentiful, low-quality pasture can result in hay gut and horse digestive tract impaction (colic). Thus, supplemental feeding on pasture is sometimes needed.

If horses have not grazed pastures all winter, they should not be turned out at once on spring pasture. Immediate access to lush, spring forages can cause colic or laminitis (founder).

A crucial factor in managing horses on pasture is to avoid abrupt changes from a fed ration to pasture and from extremes of pasture quality. Changes especially are a problem when horses are moved from a lower-quality pasture, or no pasture, to a high-quality pasture.

To prevent problems when introducing horses to pastures, feed them a normal amount of hay before turning them out, and limit grazing time to one hour the first day. Then add 30 minutes to one hour of grazing time each day, or as recommended by your veterinarian.

Eating clovers, either by grazing or in hay, often results in excessive slobbering caused by a fungus growing on the clover when conditions are adverse. While not particularly attractive, this poses no health concern to the horse.

In addition, there are a number of plants that are poisonous to horses that can make horses ill, or even kill them, if they are consumed (see plant list in Chapter: Pasture Plants).

E+ Fescue

Tall fescue infected with the toxic endophyte fungus (E+) has long been taboo for use as horse pasture or hay. Toxic E+ tall fescue affects all classes of horses, but the most dramatic effects are seen in pregnant mares. Pregnant mares grazing E+ tall fescue may develop thickened placentas resulting in foal death, and the mare may fail to lactate. Pregnant mares should not be allowed to graze E+ fescue or eat hay containing E+ fescue for 60-90 days prior to foaling.

Varieties of tall fescue are available which do not contain the toxic endophyte. These varieties should be selected for planting. It is prudent for horse owners to eradicate the E+ fescue to the greatest extent possible.

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New Jersey Pasture Management Guide for Horse Owners

Pasture Management Guide for Horse Owners (PDF, 2.15 MB)