There are approximately 100,000-110,000 domestic horses and 6,500-7,000 feral horses in Wyoming depending on the time of year. We fluctuate during foaling, show/rodeo season and tourism/hunting seasons. About 38% of these horses are kept on non-commercial properties for recreation. Many of these s sites housing 38,000-41,800 recreational horses vary from 20-200 acres in size.
A horse of 1,400 pounds eats about 40-42 pounds of forage each day or 1,260 pounds each month. Horses will eat additional amounts as they graze for socialization and so they can keep their heads down to watch for predators. An average 40-acre paddock in Wyoming will grow 1,050 pounds of grass on each acre annually, or 42,000 pounds each year.
You have to leave half un-grazed so the plants can regrow so only 21,000 pounds of growth are “usable”. Using more leads to erosion, weed infestation and property devaluation. Dividing the average usable forage by a horse’s monthly needs equates to 16.66 “horse months” on a forty acre paddock. Often this is less if located on arid areas, sand dunes or rocky soil. This example property would only support two horses for a period of 8 months in an average year. If overgrazed past 50% the production grass level on the property will drop dramatically.
Horses will fool well-meaning owners who feed concentrates and supplements to prevent overgrazing in that they have the capacity each day to consume the added nutrients and still use more grass than recommended.
I want to discuss two basic horse safety issues, specifically feeding to prevent sand colic and feeding to prevent poisoning.
Horses go after feed aggressively, and since their physiology includes agile lips and incisor teeth, which can get very close to the ground, they can get very close to elements that can negatively affect them.
When horses are fed too little or in a feeder that allows the hay to drop to the ground they may continue trying to pick up fibers on the ground leading to the consumption of soil particles in the process. Consuming too much soil or sand can generate blockages and twisting in their intestines. This can cause health issues and a risk of death.
When horses are allowed to graze paddocks well below recommended levels they will still seek, investigate and consume amounts of “novelty” plants other than normal grasses. Many of these are weeds and native plants which may be toxic or poisonous to horses. Horses will avoid these usually if suitable grass is present.
The key note here is if you have a forage-limited operation:
Carefully monitor, manage and rotate use on your pastures. It takes many grasses in Wyoming 30-45 days to recover 50% use in the growing season with rain.
Develop a holding area to house and feed horses using feeders which keep hay off the ground, and make sure there is enough feed to keep horses from searching the ground all the time.
Watch for strange plants on your property and strange behaviors by your horse.
If you have questions or concerns contact your local extension educator for horse and pasture management issues or your local veterinarian for equine health issues. Happy horses have suitable pasture and feed. Happy horse owners have healthy horses. Everything starts from the ground up.