With all of the recent rainfall, I have seen some situations in which horses that are penned in small lots are standing in water instead of grass, and we all know that is not a good thing. This brings me to the point of this discussion, how much land area does it take to support a horse, without destroying the grass in the pasture? Horses tend to be hard on pastures for a few reasons.

Often times they are overstocked, and the biting style of a horse is such that it allows them to clip plants off close to the ground, causing severe problems for plant regrowth. Other horse habits bad for pastures include: defecating in localized areas, causing manure buildup and reduced palatability of the forage in those areas and their selective grazing instinct.

So the real question is how can horse owners control the grazing of horses so they get the most out of their pasture, while at the same time prevent the horse(s) from degrading the pasture?

Many horse farms, particularly those with small acreage should consider some type of controlled grazing system. This simply means limiting the time per day horses have access to pastures and/or dividing the pasture into smaller areas and practice rotational grazing. These practices will enhance total forage production and allow higher stocking rates to be maintained.

Proper stocking rates, or the number of horses per unit of land area, are affected by several factors, including size of horse, soil type, forage species, time of year, soil moisture, soil nutrient needs and length of time horses have access to a pasture. These factors make it difficult to make a general statement providing a suggested number of head per land area.

If you plan on using a pasture as the total ration for the horse, you must consider several variables:

* Is there enough pasture to meet the needs of the animal?

* How much rainfall do you normally receive? Is irrigation of the pasture an option?

* What species of grasses are in the pasture?

* What is the soil depth and type?

* Does the horse receive supplemental hay or grain in addition to the pasture?

So after you have answered those questions, then consider calculating the stocking rate for horses. Generally, a horse weighing 1,000 pounds consumes 600 pounds of dry matter forage each month. This will calculate to 7,200 pounds of needed forage per year (600 lbs./mo. x 12 mo.). Average pastures will produce two to three tons of forage per acre over a season depending on rainfall, soil type and species of plants.

A stocking rate of 600 to 700 lbs./acre should be a good starting stocking rate for most pastures. Stocking adjustments can be made gradually according to increases or decreases in visually observed changes in forage supply, and should account for the prevailing rainfall.

Depending on the productivity of the pasture land, supplemental feeding may be required. Limiting grazing to several hours per day combined with supplemental feeding on smaller acreages will extend the length of the grazing seasons. Horses will need to be housed in a box stall or a dry lot for the period of time they are not on pasture.

Continuous grazing on pastures of limited acreages may require a recovery period of no grazing to maintain forage health and vigor.

During periods of drought, when no forage is available, supplemental hay must be provided. During periods of very wet conditions, like we are currently experiencing, and the existing forage is very limited, horses should be held in a sacrifice area, which would be a small area of your pasture that you give up and fence off to keep the horses on when the pasture is wet or in winter so that they do not destroy your grass. Then you could create a rotational grazing system with the rest of the pasture, using electrified tape or some sort of temporary fence to divide off sections that you allow them to graze on. Remember not to graze the pasture to less than three inches before you rest it. You then need to allow the grass to regrow to six inches before you graze it again. All of this hinges on having a stand of forage to work with.

Continuous heavy stocking inevitably results in the deterioration of pastures. A good indicator of excessive stocking rates is when manure piles are readily seen, and when horses are observed grazing closer to these piles. Stocking rates should be based on total body weight per acre, and not number of horses per acre. This is because a 1,000 lb. horse will consume daily approximately 40 percent more forage dry matter than one that weighs 600 lbs.

The Texas AgriLife Extension Service in Nueces and San Patricio Counties will host the Coastal Bend Pasture Symposium, on Friday, March 12, 2010, from 8:15 a.m. to 4 p.m. at the Texas AgriLife Research and Extension Center at 10345, State Hwy 44, just west of the Corpus Christi Airport. To aid with program planning, all participants are requested to preregister by March 8 by calling 361-767-5223. There will be a registration fee of $10 per person payable at the door to help offset meal costs.

Jeffrey Stapper is the Agricultural and Natural Resources Agent for Nueces County. Readers may contact him at 767-5217.