Grass, clover, and forbs
Mostly sheep eat grass, clover, forbs, and other pasture plants. They especially love forbs. It is usually their first choice of food in a pasture. A forb is a broad-leaf plant other than grass. It is a flowering plant. Forbs are often very nutritious. As compared to cattle, sheep eat a greater variety of plants and select a more nutritious diet, but less so than goats.
Grazing time
Sheep will graze for an average of seven hours per day, mostly in the hours around dawn and in the late afternoon, near sunset. When supplements are fed, it is best to feed them in the middle of the day so that normal grazing patterns are not disrupted.
Different plants
Sheep in different geographic areas eat different plants. Tropical forages are usually not as nutritious as those that grow in temperate climates. Protein is often the most limiting nutrient in forages. All forages are more nutritious if they are eaten in a vegetative state.
Pasture (land) requirements
The amount of pasture or range land that it takes to feed a sheep depends upon the quality of the land (soil), the amount and distribution of rainfall, and the management of the pasture.
In dry climates, an acre (or hectare) of pasture or rangeland cannot feed as many sheep as an acre of pasture in a moist climate. An acre of pasture in the wet season (spring and fall) can support more sheep than an acre in the dry season (usually summer)
Reproductive rates and lamb growth rates are lower in arid climates than high-rainfall areas that grow more plentiful forage. As a result, wool production tends to be of greater importance in arid and semi-arid environments, as it takes less nutrition to grow good quality wool than to produce milk and raise lambs. A farmer may be able to graze ten sheep on one acre of improved pasture in Maryland, whereas one sheep could require ten acres of native range in West Texas.
Stored feed
When fresh forage is not available, sheep are usually fed stored or harvested feeds: hay, silage, green chop, or crop by-products. Hay is grass that has been mowed (cut) and cured (dried) for use as livestock feed.
Silage (short for ensilage) or haylage is green forage that has been fermented and stored in a silo or other system that keeps air out. Moldy silage can cause listeriosis in sheep. The pieces should be chopped smaller for sheep as compared to cattle.
Sometimes, pasture plants are cut, chopped, and brought to the sheep. Fresh harvested forage is called green chop. This "cut-and-carry" system of feeding is common in developing countries, where labor is not a limiting factor.
Supplementation
Grain is often fed to sheep with higher nutritional needs, such as pregnant ewes during late gestation, ewes nursing two or more lambs, and lambs with the genetic potential for rapid growth. Grain is the seed part of cereal crops such as corn, barley, wheat, and oats. Grain is not "unnatural" for sheep. They have always eaten the seeds of plants.
A protein source, such as soybean meal or cottonseed meal is usually added to the grain ration, along with vitamins and minerals to make a 100 percent nutritionally-balanced feed. Unbalanced grain rations can lead to a variety of health concerns.
Sheep love the taste of grain and can experience digestive problems if they eat too much grain too fast. Grain consumption needs to be regulated, introduced slowly and gradually increased in the diet.
Ruminants, such as sheep, should always have some roughage (fibrous feed) in their diets. at least a pound per day for sheep. Producers in many parts of the world cannot afford to feed grain to their livestock. Whereas in some parts of the U.S. and in some years, grain is a more economical source of nutrients that forage.
By-products
By-products from crop production and food processing can also be fed to sheep. This is another advantage of ruminant livestock: they can be fed products that would otherwise go to waste and/or require costly disposal. Examples of by-product feeds include soybean hulls, peanut hulls, corn gluten feed, wheat middlings, and whole cottonseed.
With more corn being used in the production of ethanol, distiller's grains are becoming a more popular (and more economcal) feedstuff for sheep and other livestock. Distiller's grains are the solids left after ethanol is made. They are also a by-product of the brewing industry. Distiller's grains can be fed wet or dry, but are usually fed dry. Distiller's grains can contain high levels of phosphorus and sulfur, so their inclusion in sheep and lamb diets is usually limited.
