Good and Bad Grazing
Simply leaving a horse to graze in a field does not guarantee that it will feed on vegetation sufficient for a healthy diet. For starters, the nutritional value is dependent on the types of plants that grow within the area. It also depends on the state of growth of the plants; most grasses are at their most nutritious state before they go to seed. Finally, its value depends on the height of the grass. Horses prefer to graze on shorter rather than longer grasses. Areas with unpalatable plants are not grazed and the uneaten plants produce seeds and multiply, making the area worse.
Meadow grass (Poa annua)–This plant was once common in water meadows in temperate climates. It provides good ground cover and is enjoyed by horses.
Fescue (Festuca)–These grasses are relatively hardy. They are less palatable to horses than some other types, so there is a possibility that it will be ignored if the horses have alternate species to graze.
Ryegrass (Lolium)–Ryegrass grows quickly. Most seed mixes for farm use in temperate climates contain a high percentage of this plant. It is not very drought resistant, but grows well early in the season.
Timothy (Phleum pratense)–This is not a very hardy grass, even though it is very palatable, and horses will have a tendency to seek out this plant among others. Timothy is also a tasty and nutritious element in hay.
Cocksfoot or Orchard grass (Dactylis glomerata)–This can withstand spells of really dry weather during its growing season, but it does not have high carbohydrate content.
Dandelion (Taraxacum officinale)–Dandelions are useful for grazing. Their broad leaves are palatable to horses, but a horse will only be able to find them if the grass is short.
Wild Chicory (Cichorium intybus)–To humans, chicory is bitter, but is often without reserve by animals. Wild Chicory is nutritious for horses because it has a good mineral content.
White Clover (Trifolium repens)–Clover has high starch content. Unfortunately, because it is so rich it can cause laminitis to develop, so a high pasture percentage is undesirable for ponies.
Thistle (Carduus)–Thistles are painful to eat and the spines from the leaves can damage the mouth. They grow tall and spread their seeds well, multiplying easily.
Nettle (Urtica dioica)–Nettles sting the inside of a horse’s mouth, so horses generally will not eat them willingly. They are a problem because they grow rapidly, smothering more desirable plants.
Yorkshire Fog (Holcus lanatus)–The plant is not harmful to horses, but it has little nutritional value. It is a nuisance because it impedes the growth of other species of grass in a pasture.
Couchgrass (Agropyron repens)–This type of grass has a relatively low nutritional value. It spreads rapidly by extending new growth through surrounding vegetation rather than relying on seeds. It can stop other, more desirable plants from thriving.