Pasture management for horses
Tania Cubitt | 18.10.20
From the start
Many breeds and types of horses are used in a wide variety of activities throughout Australia. The majority of these horses are owned and managed for recreation or sport and not for profit by the owners. One of the greatest expenses in owning horses is feed. Feed costs can be minimized by keeping the horse healthy and by feeding a balanced ration that meets the horses nutritional needs. More myths are associated with feeding horses than with feeding most other animals. This is in part due to the lack of current nutritional research information compared to other species as well as an increasing number of horse owners who are unfamiliar with the basics of horse nutrition. Nutritional requirements vary considerably among horses depending on individual age, weight, and level of activity. There are no magic supplements; high performance feed "secrets", or short cuts that will transform any horse into a champion. Horses naturally use forages as a primary component of their diets. Adequate forages are a basic necessity for normal functioning of the horse's digestive system. This requirement for forages is most easily supplied by pasture and hay. Mature horses will generally consume 2 to 2.5 percent of their body weight in feed each day. For example, a 500kg horse should consume approximately 10 to 12.5 kg (90 percent dry matter) of feed per day. The anatomy of the horse's digestive tract restricts effective digestion and utilization of low quality forages that are high in fiber. The poor digestion of low-quality forages can restrict the amount of dry matter that a horse can eat to a level below what is necessary to meet the horse's nutrient needs. Therefore a premium should be placed on using high-quality forages in the horse's diet. Ideally, horses should consume a minimum of 1 percent of their body weight in hay or pastures each day. Mature horses performing minimal or no work can be maintained on high quality forages without supplementing their diet with grain. However, growing, breeding, or working horses requires supplementing the forage with a quality grain or concentrate to meet their additional nutrient requirements. As a general rule, forages should supply one half or more of the total weight of feed consumed daily for optimum horse growth and development. Forages can provide varying amounts of the nutrient requirements depending on the forage quality and amount consumed. The nutrient content of the forage and concentrate in the horse's diet must be known to properly balance the diet. Once the quality of the feeds are known, then proper amounts of each can be calculated to meet the nutrient requirements.
Pasture for horsesHigh quality, pasture represents one of the best and least expensive sources of feed for a horse. In addition, a well-managed pasture can provide the most natural and healthy environment for exercise and rest. Productive, well-managed pastures can provide most of the feed requirements of horses at the lowest cost. In fact, good pasture alone is sufficient to meet most of the nutritional requirements for many classes of horses such as Idle and lightly exercised horses. Yet, poorly managed pastures supply little or no feed, and are frequently the source of many internal parasites, thus supplementation will need to occur. General guidelines for the pasture area requirements (if the pasture is to serve as a feed source) for horses, which have a mature weight of 450 to 550 kg. Are:
- Mare and foal 1.75 to 2 acres
- Yearlings 1.5 to 2 acre
- Weanlings 0.5 to 1 acre
When acreage is very limited (less than one acre per horse), exercise may be the main use of the pasture. Pasture for this purpose will not supply more than a minimum amount of feed. However, with limited pasture acreage, rotational grazing systems are the most effective method to maximize forage production and consumption. In this system, a group of compatible horses can graze a paddock (area of divided pasture) for approximately 3 to 6 days and then be moved (rotated) to a fresh paddock. Well-limed and fertilized ryegrass or phalaris should be the main grass for this type of area. Phalaris and cocksfoot withstands close and continuous grazing better than most other grasses and when well established and properly fertilized, it produces a reasonably dense and attractive sward.
When planning to renovate a horse pasture, the first thing you should do is to walk the pasture and determine what plant species currently exist and make an assessment of the overall condition of the pasture. If the pasture consists primarily of grass and/or legume species, but is being considered for renovation due to low productivity, changes in pasture management may be more effective and more economical than a complete renovation. Such things as fertilizer weed control and grazing management may produce big gains. If, on the other hand, few desirable species are present, and the pasture is infested with weeds, then renovation may be the best solution. If the site was previously in some other crop, then renovation will also be required to establish the desired pasture species.
Soil sampling and analysis
The best time to take a soil sample for analysis of nutrient requirements is prior to a new seeding. This will allow you to incorporate any needed fertilizers into the seedbed, or to spread them near the seed at time of seeding. This allows for more efficient use of fertilizers, especially phosphorous and lime which need to be in the root zone, as they do not move down readily when applied on the surface. High phosphorous levels are important for encouraging good root growth and to improve seedling vigor. Micronutrients such as boron and molybdenum may also be applied and incorporated prior to seeding. Nitrogen and potassium may be applied after the crop has become established. High levels of nitrogen and potassium prior to seeding are not desirable as it may promote vigorous weed growth and can cause root burning and injury of seedlings.
Pasture improvementIf you already have good stands of desirable grass and legume species, proper soil fertility combined with good management will be sufficient to assure a good horse pasture. Most permanent horse pastures produce far below their potential. Yields on many pastures can be doubled simply by applying lime and fertilizer. Liming and topdressing pastures with phosphate, potash and nitrogen costs much less and is less work than complete pasture renovation. Furthermore, it is often possible to have these materials custom applied at a relatively low cost. Apply lime and fertilizer according to soil test results and recommendations. A soil test will determine the pH (acidity) and nutrient level of your soil. Soil testing kits and information on how to take samples are available through your local agriculture department extension officer or your local agricultural store. The response is often slow when you apply lime and fertilizer on the surface of established pastures. It may take 3 to 5 years, depending largely on the lime needs and species present in the pasture, before your pasture sward is thick and productive again. If you don't have a good stand of desirable species, you may want to renovate the pasture by destroying the existing plants and planting productive mixtures. This procedure usually results in the highest yield increase per acre, but will also be relatively expensive to complete. If you plan to renovate an old pasture you should consider the following points:
- Soil test for lime and fertilizer requirements. This is the only sure way of knowing how much lime and fertilizer are needed
- Apply required lime several months before the actual seeding. Disking or ploughing will help to mix the lime evenly throughout the soil.
- Select a seed mixture that complements the pasture drainage and climatic characteristics.
- Destroy or suppress the old pasture by ploughing or use of herbicides.
- Use the appropriate method of seeding based on extent of tillage.
- Protect the seeded area until the new plants are well established. Where recommended mixtures are seeded without a companion crop and weeds are controlled, new seedings can become established in a single year.
- Importantly, Keep your horses off the newly established pasture for at least 90 days. Longer would be more desirable.
In heavy traffic areas, along fences and around gates and water troughs, phalaris, cocksfoot or tall fescue may be used. While it is generally considered less palatable than ryegrass, the aforementioned species produces one of the toughest and heavy traffic swards of any adapted grass, which is desirable for horses. Older stands of fescue often are infested with an endophyte (within the plant) fungus. Toxins associated with this fungus can cause lowered reproductive rates, abortion, agalactia (lack of milk) and prolonged gestation with mares. Use endophyte-free tall fescue seed whenever establishing new fescue stands for horses. Brood mares should be removed from pastures containing endophyte infested tall fescue at least 90 days prior to foaling.
Whether you improve your pastures by the use of lime and fertilizer or by reseeding, sound management is essential to keep the desired species persistent and productive. Avoid over or under grazing. Horses are notorious selective grazers. They will seriously damage desired species in some areas unless they are moved into new pastures frequently. Therefore, some form of rotational grazing is desirable. The correct acreage per horse changes with the season as well as with other factors. However, a good rule is to provide at least one acre of good quality pasture per horse. Then set up 5 or 6 paddocks, letting the horses graze first in one area for about one week and then change to another. This system helps to keep the legumes and grasses growing better and increases the feed available per acre. In addition, by rotating the horses from pasture to pasture you can break the life cycle of some parasites. Top pastures regularly during the growing season. Toping at a height of 5 to 8 cm after horses are moved to a new paddock helps to control weeds, prevent grasses from heading and in general keeps the pasture in a more desirable condition and maximizes nutritional value. Harrow pastures with a chain link harrow at least once per year. Harrowing helps to spread manure droppings which reduces the parasite populations by exposing them to air and sunlight. Harrowing also helps to smooth over areas dug up by horses' hoofs on wet soil. Apply fertilizer as needed. Improved horse pastures must be fertilized annually if legumes and grasses are to persist and remain productive. The fertilizer to use depends on the pasture species present. Complete soils test every 2 or 3 years is your best guide.
Weed identification and control
Prior to any tillage operations, it is important to determine what weed species are growing on the site, as some species (e.g. Dock, Cape weed, Pattersons curse) may be more effectively controlled by applying a herbicide before any cultivation is done. Cultivation procedures such as discing or rotovating such plants as Dock and Cape weed may just spread these weeds throughout the paddock, as they can regrow from a small fragment of root material. For specific information on weed control contact your farm supply outlet or your local office of the Department of Agriculture.
When to feed
The decision of when to start feeding your horse and what to feed is an extremely important question. When pasture quality and quantity is limited, several adjustments to your horses ration have to be made. These are greatly determined by the size, weight and activity of your horse. Most idle horses will be able to satisfy their nutritional requirements. Growing, Stud and Performance horses will have to be supplemented with a quality feed. During these times stud formulations such as HYGAIN® BALANCED® that are high in vitamins and minerals are preferred, as these are the first limiting factors in poor quality pasture. If no pasture is available then a full supplementary ration will have to be formulated. It is not uncommon for a majority of performance horses to be stabled for a majority of the day. Obviously supplementation will occur. Full feeds will be used in conjunction with quality roughage. Remember that a horse requires at least 1% of their body weight a day in roughage.