An introduction to feeding small ruminants
Feed is the single largest cost associated with raising small ruminants, typically accounting for 60% or more of total production costs. It goes without saying that nutrition exerts a very large influence on flock health and productivity, as well as profitability.
Late-gestation and lactation are the most critical periods for ewe and doe nutrition, with lactation placing the highest nutritional demands on ewes/does and late gestation being the most crucial time for proper nutrition. Nutrition level largely determines growth rate in lambs and kids. Lambs and kids with higher growth potential have higher nutritional needs, especially with regards to protein. Animals receiving inadequate diets are more prone to disease and will fail to reach their genetic potential.
Small ruminants require energy, protein, vitamins, minerals, fiber, and water in their dets. Energy (calories, TDN) is usually the most limiting nutrient, whereas protein (CP) is the most expensive. Deficiencies, excesses, and imbalances of vitamins and minerals can limit animal performance and lead to various health problems. Fiber (bulk) is necessary to maintain a healthy rumen environment and prevent digestive upsets. Water is the cheapest feed ingredient, yet often the most neglected.
Many factors affect the nutritional requirements of small ruminants, including productive status and level, activity, and environment. As a general rule of thumb, sheep and goats need to consume 2 to 4 percent of their body weight on a dry matter (DM) basis in feed to meet their nutrition requirements throughout their life. The exact percentage varies according to the size (weight) of the animal, with smaller animals needing a higher intake (percentage-wise) to maintain their weight.
Maintenance requirements increase as the level of the animals' activity increases. For example, a sheep or goat that has to travel a farther distance for feed and water will have a higher maintenance requirements than housed animals. Environmental conditions also affect maintenance requirements. In cold and severe weather, sheep and goats require more feed to maintain body heat. The added stresses of pregnancy, lactation, and growth further increase nutrient requirements.
The following chart gives the nutritional requirements for various classes of sheep and goats:
The next chart gives typical "book values" or "ballpark" figures for the nutritional content of various feedstuffs commonly fed to sheep and goats.
A sheep or goat's nutritional requirements can be met by feeding a variety of feed stuffs. Feed ingredients can substitute for one another so long as the animals’ nutritional requirements are being met and the animals will readily consume the offered diet. Small ruminant feeding programs should take into account animal requirements, feed availability, and costs of nutrients.
Pasture, forbs, and browse
Pasture, forbs, and browse are usually the primary and most economical source of nutrients for sheep and goats, and may be all that small ruminants need to meet their nutritional requirements. Pasture tends to be high in energy and protein when it is in a vegetative state.
However, pasture can have a high moisture content, and sometimes it can be difficult for high-producing animals to eat enough forage to meet their nutrient requirements. As pasture plants mature, palatability and digestibility also decline, thus it is important to rotate pastures to keep plants in a vegetative state. During the early part of the grazing season, browse (woody plants, vines and brush) and forbs (weeds) tend to be higher in protein and energy than cultivated plants.
Sheep are excellent weed eaters. Goats are natural browsers and have the unique ability to select plants when they are at their most nutritious state. Sheep and goats that browse have fewer problems with internal parasites (worms).
Hay is the primary source of nutrients for small ruminants during the winter or non-grazing period. Hay varies considerably in quality, and the only way to know the nutritional content is to have the hay analyzed by a forage testing laboratory. Hay tends to be a moderate source of protein and energy for sheep and goats. Legume hays (alfalfa, clover, lespedeza) tend to be higher in protein, vitamins and minerals, especially calcium, than grass hays.
The energy, as well as protein content of hay depends upon the maturity of the forage when it was harvested for hay. Proper curing and storage is also necessary to maintain nutritional quality of hay.
Silage made from forage or grain crops has been successfully fed to both sheep and goats; however, special attention must be paid to quality, as moldy silage can cause listeriosis or "circling disease" in small ruminants. As with fresh forage, the high-producing animal often cannot consume enough high moisture silage to meet its nutritional needs. Silage is typically fed on large farms, due to the need for storage and automated feeding equipment.
It is oftentimes necessary to feed concentrates to provide the nutrients that are deficient in a forage-only diet. This is particularly true in the case of high-producing animals, such as lactating females and lambs and kids with the potential for rapid growth. There are also times and situations where concentrates are a more economical source of nutrients than pasture or hay. Creep feeding and supplemental feeding of lambs and kids has been shown to increase growth weights, but should only be done to the extent that it increases profit.
There are two types of concentrate feeds: carbonaceous and proteinaceous. Carbonaceous concentrates or "energy" feeds tend to be high in energy, but low in protein (8-11%). They include the cereal grains --corn, barley, wheat, oats, milo, and rye. It is generallly recommended that grain be fed whole to sheep and goats. It is not necessary to process (crack, role, or grind) grains for sheep and goats unless the animals are less than six weeks of age and lack a functioning rumen.
One of the problems with feeding a lot of cereal grains is that they are high in phosphorus (P) content, but low in calcium (Ca). Feeding a diet that is high in phosphorus and low in calcium can cause urinary calculi (kidney stones) in wethers and intact males, especially if they are not consuming adequate forage. Inadequate calcium can lead to milk fever (hypocalcemia) in pregnant or lactating females.
Proteinaceous concentrates or "protein supplements" contain high levels of protein (>15%) and may be of either animal or plant origin. They include soybean meal, cottonseed meal, and fish meal. Ruminant-derived meat and bone meal cannot (by law) be fed to other ruminants, including sheep and goats. Protein quantity is generally more important than protein quality (amino acid content) in ruminant livestock since the microorganisms in the rumen manufacture their own body protein. By-pass protein bypasses rumen degradation and is advantageous in the diets of sheep and goats. Fish meal has the higher percentage of by-pass protein.
Livestock do not store excess protein; it is burned as energy or eliminated (as nitrogen) by the kidneys. Too much protein in the diet can have a detrimental effect on metabolism. Since parasites often cause blood (and protein) loss in small ruminants, higher levels of protein in the diet may enable the animal to mount a greater immune response to parasites.
By-products feeds, such as fat, soy hulls, wheat middlings, distiller's grain, and broiler litter may contain high levels of various nutrients and can be incorporated into small ruminant diets if they are cost effective. Due to its copper content, it is not recommended that sheep be fed broiler litter for sustained periods of time. By-products feeds can vary in their nutritional composition, so it is important to test them before incorporating them into the ration.
Many feed companies offer "complete" sheep and/or goat feeds -- pelleted or textured -- which are balanced for the needs of the animals in a particular production class. Pelleted rations have an advantage in that the animals cannot sort feed ingredients. Textured feeds are usually more palatable. While complete sheep feeds have been available for many years, it has only been in recent years, that meat goat rations have been introduced to the market place. Complete feeds come in 50 or 100 lb. sacks and tend to be much more expensive than home-made concentrate rations. However, they are 100 percent nutritionally balanced.
Vitamins and minerals
Many minerals are required by small ruminants. The most important are salt, calcium, and phosphorus. The ratio of calcium to phosphorus should be kept around 2:1 to prevent urinary calculi. Vitamins are need in small amounts. Small ruminants require vitamins A, D and E, whereas vitamin K and all the B vitamins are manufactured in the rumen.
A free choice salt-vitamin-mineral premix should be made available to small ruminants at all times, unless a premix has been incorporated into the grain ration or TMR (total mixed ration). In the very least, ewes and does should be fed pre-choice mineral during late gestation and lactation. Loose mineral is preferred to mineral blocks. It is better to incorporate the vitamins and minerals into the grain ration or TMR rather then to offer them free choice, since animals will not consume minerals according to their needs.
Many soils are deficient in selenium, thus the premix should be fortified with selenium to prevent white muscle disease in lambs and kids and reproductive problems in females. Supplementing selenium via the feed or mineral is preferred to giving selenium injections. Goats have a higher requirement (and higher tolerance) for copper in their diets as compared to sheep, thus it is recommended that feeds and/or premixes contain copper, unless the goats are co-mingled with sheep. Sheep should be fed mineral mixes that have been specifically formulated for sheep.
It is possible to get pelleted supplements that contain vitamins and minerals, as well as high levels of protein (34-40%). These supplements can easily be combined with whole grains or by-product feeds to create a balanced concentrate ration. Coccidiostats and antibiotics can also be added to the mineral mix or supplement. Bovatec® (lasalocid) is FDA-approved to prevent coccidiosis in feedlot lambs. Rumensin® (monensin) is FDA approved for confined goats. Deccox® is approved as a coccidiostat for both species.
Small ruminants should have ad libitum access to clean, fresh water at all times. A mature animal will consume between ¾ to 1 ½ gallons of water per day. Water requirements and intake increase greatly during late gestation and during lactation. Water requirements increase substantially when environmental temperatures rise above 70°F and decline with very cold environmental temperatures.
An animal’s nutrient requirements will increase if it has to consume cold water during cold weather. Rain, dew, and snowfall may dramatically decrease free water intake. Inadequate water intake can cause various health problems. In addition water and feed intake are positively correlated.
References and further reading
Nutrient Requirements of sheep, Sixth Revised Edition (1985) - NRC
This article was written in 2003 by Susan Schoenian. It was last updated in 2015.