SOME KEY POINTSFeed is the single largest cost associated with raising sheep.Sheep can be fed different feedstuffs so long as they are in balance with their needs for energy, protein, vitamins, minerals, fiber, and water.Energy is usually the most limiting nutrient and is the ingredient fed in the greatest quantity.All sheep should have long stemmed forage (effective fiber) in their diets.Water is the most important nutrient and often most overlooked.As with people, sheep do not require specific feeds. They require energy, protein, vitamins, minerals, fiber, and water. Many different feedstuffs can meet their nutritional requirements.EnergyEnergy makes up the largest portion of the diet and is usually the most limiting nutrient in sheep diets. Carbohydrates, fat, and excess protein in the diet all contribute towards fulfilling the energy requirements of sheep. Carbohydrates are the major sources of energy. Concentrates (grain) contain starch, which is a rich source of energy. Forages contain fiber or cellulose, which is not as rich in energy as starch. The major sources of energy in a sheep's diet are pasture and browse, hay, silage, and grains.Meeting energy requirements without over or underfeeding animals is one of the producer's biggest challenges. An energy deficiency is the most common nutritional deficiency in sheep. An energy deficiency will manifest itself in many ways. In growing animals, an early sign of energy deficiency is reduced growth, then weight loss, and ultimately death. In reproducing females, early signs of an energy deficiency are reduced conception rates, fewer multiple births, and reduced milk production.With restricted energy consumption, wool growth slows, fiber diameter is reduced, and weak spots (breaks) develop in the wool fiber. An energy deficiency reduces the function of the immune system. Undernourished sheep are more susceptible to diseases, especially gastro-intestinal worms.Excess energy consumption can cause problems in sheep, too. Extra energy is stored as fat (adipose tissue). Gross excesses in adipose tissue impair reproductive function in rams and ewes. During late gestation, fat ewes are more prone to ketosis (pregnancy toxemia) and dystocia. Fat lambs do not gain efficiently and they are undesirable to most consumers.Energy is quantified in the ration in many ways. The simplest measure is TDN, which is the acronym for " total digestible nutrients." Metabolizable energy (ME) and net energy (NE) values are more accurate measures of energy in a sheep's diet. TDN is usually used to formulate rations for breeding animals, while the net energy system is often used to calculate diets for growing lambs.Protein Protein is usually the most expensive part of the diet. Since the rumen manufactures protein from amino acids, the quantity of protein is more important than the quality of protein in a sheep's diet. Protein requirements are highest for young, growing lambs who are building muscle and lactating ewes who are producing milk proteins.The most common protein supplement for sheep is soybean meal. Other less common sources include sunflower meal, cottonseed meal, whole cottonseed, whole soybeans, peanut meal, canola (rapeseed) meal, fish meal, and alfalfa pellets. In most countries, it is illegal to feed meat and bone meal from other ruminants. Legume hays, when they are harvested in the early to mid-bloom stage, are intermediate sources of protein.Though levels vary, grains are usually low in protein. Urea is the most inexpensive source of protein or dietary nitrogen. Urea is converted to protein in the rumen. It has an equivalent crude protein value of 280 percent. It needs to be carefully incorporated into sheep rations and should not be included in creep rations.Protein blocks are the most expensive way to provide supplemental protein to pastured animals, but they save labor. The hardness of the block regulates intake by the sheep. Excess protein is an expensive and inefficient source of energy. It can have a detrimental effect on animal health, as excess protein is converted blood urea and ammonia. Animals overfed protein excrete more nitrogen in their urine and feces. Minerals Sixteen (16) minerals have been classified as nutritionally essential in sheep diets. Macro-minerals are required in larger amounts, usually grams or ounces. They include sodium (Na), chloride (Cl), calcium (Ca), phosphorus (P), magnesium (Mg), Potassium (K), and Sulfur (S). Microminerals (also called trace minerals) are required in smaller amounts, usually milligrams or parts per million (PPM). They include iodine (I), copper (Cu), iron (Fe), manganese (Mn), zinc (Zn), molybdenum (Mo), cobalt (Co), selenium (Se), and fluoride (Fl), are required in small amounts.Salt Salt (sodium [Na] and chloride [Cl]) has an important regulatory function in the body. Inadequate salt intake can decrease feed and water intake, milk production, and growth of lambs. Animals desiring salt may chew on wood and/or lick dirt. They are more likely to consume poisonous plants. When adding salt to mixed rations, it is customary to add 0.5 percent to the complete diet or 1 percent percent to the concentrate portion. Salt is sometimes used to limit the intake of free choice mineral mixes. It can be used to regulate the intake of feed.Calcium and phosphorus Calcium (Ca) and phosphorus (P) are interrelated in the development and maintenance of the skeleton. Deficiencies may result in rickets. An imbalance of Ca and P in the diet can cause urinary calculi in male sheep, especially wethers. The calcium in most forages is usually adequate to meet the needs of sheep. Deficiencies of calcium most often result when high-grain diets are fed, as cereal grains and oilseeds are high in phosphorus and low in calcium. The ratio of calcium to phosphorus in the sheep's diet should be at least 2:1.Vitamins Sheep require vitamins A, D, and E. Vitamin A is absent in plant material, but is synthesized from beta-carotene. Vitamin D is required to prevent rickets in young animals and osteomalacia in older animals. B-vitamins are not required in the diets of ruminants because they are synthesized in the rumen. Vitamin K is essential for blood clotting. Dietary supplementation is usually not necessary.Fiber Fiber adds bulk to the diet and keeps the sheep's rumen functioning properly by increasing rumination and salivation. Most ruminant nutritionists agree that sheep should always have roughage (long stem fiber) in their diets, at least one pound per head per day. Sheep that do not consume adequate forage may chew on wood or wool.Water Water participates in nearly all body functions and is the most important "nutrient," though oftentimes the most neglected aspect of feeding sheep. A sheep will consume anywhere from ½ to 4 gallons of water per day, depending upon its physiological state and the environmental conditions.Voluntary water intake is usually 2 or 3 times dry matter intake and increases with high-protein and high-salt diets. Decreased water intake may reduce milk production in ewes and growth rates of lambs. Animals than consume adequate water have fewer digestive upsets and a lower incidence of urinary calculi (kidney stones).

SOME KEY POINTSA sheep's diet can be met with a variety of feedstuffs.Forages are the most natural diet for sheep and often most economical.Supplemental feeding of sheep and lambs is common to meet increased nutritional requirements. Ensilage can be fed to sheep so long as it is made, stored, and fed properly.While forages are the most "natural" diet for sheep and lambs and often most economical, a sheep's nutritional requirements can be met by feeding a variety of feedstuffs. The rumen is an adaptable organ. It can easily adapt to different feeding programs, so long as it is given ample time to adjust to changes in the diet.Feedstuffs can substitute for one another so long as the sheep's nutritional requirements are being met, nutritional imbalances are not created, and the health of the rumen is not compromised. Feeding programs should consider animal requirements, desired level of performance, feedstuff availability, costs of nutrients, and the labor to deliver the feed.Pasture, forbs, and browsePasture, range, forbs, and browse are usually the primary and most economical source of nutrients for sheep and lambs, and in many cases all that sheep and lambs need to meet their nutritional requirements. For example, from the time a ewe weans her lambs through her first 15 weeks of pregnancy, medium-quality forage will likely meet all her nutritional needs. Lambs can be finished on high quality forage diets.Pasture is high in energy, protein, and palatability when it is in a vegetative state. However, it can have a high moisture content when it is rapidly growing, and sometimes it can be difficult for high-producing animals to eat enough "wet" forage to meet their nutrient requirements. Vegetation with high moisture content can also cause sheep and lambs to have loose feces that can accumulate on their back sides. For this reason, it is important to dock lambs that will be finished on pasture. Bloat is not uncommon when sheep are grazing the first grass of the spring or certain legumes.As pasture plants mature, their palatability, digestibility, and nutritive value decline, thus it is important to rotate and/or clip pastures to keep plants in a vegetative state. Forbs often have higher digestibility and crude protein levels than grasses at similar stages of maturity. It is becoming popular in some countries to graze sheep on herbs (chicory and plantain). Sheep are excellent weed eaters and will often choose to eat broadleaf weeds over grass. Because of their preference for weeds, sheep are often used to control invasive or noxious weeds, such as leafy spurge, knapweed, and kudzu. There is some interest in hydroponic fodder (e.g., barley sprouts) as a feed source for sheep and other livestock. Hydroponic fodder is a nutritious feed; however, its high moisture (~80 to 85 percent) content usually makes it an expensive feeding option. Hydroponic fodder is usually fed as a portion of the diet or mixed into a TMR (total mixed ration).HayHay is forage that has been mowed (cut) and cured (dried) for use as livestock feed. It is usually the primary source of nutrients for sheep during the winter months or dry season when forage plants are not actively growing. Hay varies significantly in quality, and while hay quality can be affected by many different factors, but especially maturity of the plants when they were harvested for hay.Proper harvesting and storage are necessary to maintain the nutritional quality of hay. Hay that is stored outside without cover deteriorates rapidly in quality. The only way to know the "true" nutritive value of hay is to have it analyzed at a forage testing laboratory. A list of certified forage testing laboratories can be found at www.foragetesting.org. Hay is usually a moderate source of protein and energy for sheep and lambs. While good grass hays can have as much energy as legume hays, legumes have 50 to 75 percent more protein and three times as much calcium. However, a good quality grass hay will be a better source of nutrients than a low or medium-quality legume hay if it is more digestible and palatable. The important thing about hay is to feed the right hay at the right time. The is no "best" hay. From an economical standpoint, the "best" hay is the hay that provides nutrients at the lowest cost. Palatability is important to the extent that the more hay sheep refuse the higher cost it will be, due to wastage (though wasted hay can make good bedding and bedding can also be expensive).An average quality grass hay is usually more than adequate for ewes during maintenance and in early to mid-gestation. Grass hay almost always meets the needs of mature rams and wethers. A mixed grass-legume hay can be fed to ewes in late gestation to meet their increased need for calcium and other minerals.It is best to save legume hays, such as alfalfa, for the lactation diet due to their higher levels of protein and calcium. If a grass hay is fed during late gestation or lactation, it may be necessary to provide an additional source of calcium to pregnant ewes and supplemental calcium and protein to lactating ewes.Table: Different kids of hayGrasses LegumesBermudagrassAlfalfa BromegrassBirdsfoot TrefoilKentucky bluegrassCow peasNative grassesLespedezaOrchardgrassPeanutReed canarygrassRed cloverRyegrassSoybeanTall fescueWhite/ladino cloverTimothyVetchIf hay is not grown on the farm, it should be purchased (or priced) according to weight. A sheep's nutritional requirements are based on weight not volume and you will not know what it costs to feed your sheep unless you know how many pounds your sheep are eating and what the feed cost per unit of weight is. Wastage (or refusal) can factor heavily into the cost of hay. The weight of hay bales (small square, round, and large square) varies significantly and needs to be considered. When hay is purchased by the bale and you do not know what the bales weigh, you could be spending a lot more for hay than you think. It is seldom the other way around. Most hay auctions sell hay by the ton. If you buy hay from a farm, you can ask the farmer to sell you hay by the ton and weigh the load of hay on a commercial scale or you can weigh some representative bales, then negotiate a per bale price.Just because you produce your own hay does not mean it is free. If you produce your own hay, the cost to the sheep operation would be the "opportunity" cost of the hay. An opportunity cost is the value of a resource for its next-highest-value alternative. In the case of hay, this is usually the income you would receive from the hay if you sold it (less marketing costs).Silage or Haylage (ensilage)Silage (or ensilage) is a generic term for livestock feed that is produced by the controlled fermentation of high moisture herbage. Silage can be made from forage or grain crops. It has been successfully fed to sheep; however, special attention must be paid to quality, as moldy silage can cause listeriosis "circling disease," a usually fatal neurological disease. Listeriosis can also be a cause of abortion in ewes. As compared to cattle, sheep are more susceptible to the negative effects of moldy silage. It is important that sheep consume silage before it has a chance to spoil. You should only put out the amount they can consume in a day.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 can be a more economical source of feed than traditional feeds. For small and medium sized flocks, silage bags make silage feeding a possibility.BaleageIt has become increasingly popular to feed baleage to sheep. Baleage is "wet wrapped hay." It is forage with a relatively high moisture content that is baled with a round baler, then sealed in a plastic bag or wrapped in plastic to keep oxygen out. While dry hay is less than 20 percent moisture and silage is usually more than 65 percent moisture, baleage is usually ensiled at 40 to 60 percent moisture. Baleage is easier to make in the spring, when rainfall is unpredictable.Concentrates (grain)Concentrates are feedstuffs that are high in nutrients. It is often necessary to feed concentrates to sheep to provide the nutrients that the forage diet is deficient in. This is particularly true in the case of high-producing animals. There are also times and situations where concentrates are a more economical source of nutrients than forages. Creep feeding and supplemental feeding of lambs has been shown to increase weight gains and market acceptability. The economics of supplemental feeding will vary by operation.Energy feedsThere are two types of concentrate feeds: carbonaceous and proteinaceous. Carbonaceous concentrates or "energy" feeds are high in total digestible nutrients (TDN) but tend to be low in protein (8 to 11 percent ). The most common energy feeds are the cereal grains: corn, barley, wheat, oats, milo (grain sorghum), and rye. Some by-product feeds are also high in energy.It is usually not necessary to process grains (grind, crack, roll, or crimp) for sheep except for lambs that are less than six weeks of age and lack a functioning rumen. In fact, whole grain diets are healthier for the rumen because they require the animal to do its own grinding of the feed. Whole grain diets are less likely to cause digestive upsets, such as acidosis. Whole, uncooked (raw) soybeans may also be fed to sheep. While cereal grains are the most concentrated source of energy, they are high in phosphorus and low in calcium. Feeding a diet that is high in phosphorus and low in calcium can cause urinary calculi in males, especially wethers. Inadequate calcium can lead to milk fever in pregnant or lactating ewes. It is important to understand that cereal grains are an energy source, not a complete feed.Excessive or sudden intake of grain (starch) can cause numerous digestive and metabolic problems in sheep and lambs, including enterotoxemia (overeating disease), acidosis (grain overload), bloat, and polioencephalomalacia. The rumen always needs time to adjust to a higher concentrate diet, as there are different microbes for digesting starches and sugars versus cellulose (fiber). Grain should always be introduced and increased gradually.Table: Energy feedsFeedstuffPercent TDNWhole cottonseed91Wheat middlings90 Corn grain (maize)89Wheat grain89Grain sorghum (milo)89Barley grain84Corn gluten feed83 Ear corn82Rye grain81Soybean hulls77Molasses75Beet pulp pellets74Oat grain74Protein feeds Proteinaceous concentrates or "protein feeds" contain high levels of protein (usually over 20 percent). Examples include soybean meal, cottonseed meal, and fish meal. In the US, soybean meal is the most commonly fed protein supplement and often the most economical. Whole cottonseed is another common source of protein for livestock, especially in the South. By law, ruminant-derived meat and bone meal cannot be fed to other ruminants, including sheep. Fish meal is valued for its high level of by-pass protein. Roasted soybeans contain more by-pass protein than uncooked beans or bean meal.Protein quantity is generally more important than protein quality (amino acid content) in ruminant diets because the microbes in the rumen manufacture their own protein. Livestock do not store excess protein; it is either burned as energy or eliminated (as nitrogen) by the kidneys. Feeding protein above NRC requirements will not usually increase productivity or carcass quality.Since parasites often cause blood loss in sheep and lambs, higher levels of protein in the diet may enable the animal to mount a greater immune response to parasites, especially the blood-sucking barber pole worm. Research has shown that protein supplementation (above NRC requirements), especially by-pass protein, can reduce fecal egg counts in periparturient ewes.UreaUrea is not a protein supplement but is a source of nonprotein nitrogen (NPN) that rumen bacteria can use to synthesize protein. NPN should be used only in conjunction with high-energy feeds such as corn. Urea, which is 45 percent nitrogen and has a crude protein equivalent of 281 percent, should not supply over one-third of the total nitrogen in a diet. It should not be fed to very young lambs. It should be included in the same diet as raw soybeans.Table: Protein FeedsFeedstuffPercent CP (crude protein)Urea281Fish meal62Soybean meal48Whole soybeans42Linseed meal34Protein pellet36 to 40Corn gluten feed26Distillers grains (DDSG)25Brewers grains24Whole cottonseed21Alfalfa pellets17Protein (lick) tubs16 to 30Commercial FeedsMany feed companies offer "complete" sheep and/or lamb feeds. These are textured (sweet) or processed (pelleted) feed products which have been balanced for the needs of sheep of a specific age or production category. Complete feeds should not be mixed with other grains, because this will "unbalance" them. For example, adding corn to a complete feed will alter the Ca:P ratio and could result in urinary calculi in male lambs. It will also reduce the protein percentage.Pelleted rations have an advantage in that the animals cannot sort feed ingredients. Sorting can be a problem when animals are on self-feeders and allowed to eat all they want. Pelleted diets are ideal for free choice self-feeding. Complete feeds come in 50 or 100 lb. sacks and tend to be more expensive than home-made concentrate rations. For small producers, inexperienced shepherds, and 4-H members, commercial feeds are usually recommended.Pelleted Supplements To help control feed costs, producers can mix their own simple rations by combining various feed ingredients, such as corn, soybean meal, and minerals. It is also possible to buy commercial pelleted supplements that contain vitamins and minerals, as well as high levels of protein (34 to 40 percent). These supplements can easily be combined with whole grains or by-product feeds to create balanced concentrate rations.For example, combining 4 lbs. of corn with 1 lb. of a 36 percent protein pellet would result in a 16 percent protein ration that includes vitamins and minerals, making it a "complete" ration. This ration would be suitable for feeding lactating ewes or finishing feeder lambs. The pellets mix better with whole grains than soybean meal and loose minerals, which may fall to the bottom of the trough.By-product feedsThere are numerous by-products that can be fed to sheep and lambs. Most by-products are available as a result of processing a traditional feed ingredient to generate another product. For example, corn gluten meal is a by-product of the corn milling process. Soybean hulls are a by-product of soybean processing for oil and meal.Wheat middlings are a by-product of the flour milling industry. Beet Pulp is the vegetable matter, which remains after sugar is extracted from sliced sugar beets. Brewers grains is a by-product of the brewing industry. Citrus Pulp is the dried residue of peel, pulp and seeds of oranges, grapefruit and other citrus fruit. Sheep can also be fed waste products, such as cull onions and pumpkins, and out-dated (expired) human food stuffs. By-product feeds can be economical sources of nutrients for sheep; but because they are variable, they should always be tested to determine their nutritive content. Some by-product feeds contain high levels of certain minerals. For example, distiller's grains are usually high in sulfur. This needs to be considered when balancing rations. The high moisture content of some by-product feeds could limit consumption of the diet resulting in poor animal performance. High water content may also make by-product feeds difficult to transport and store. By-product feeds are often incorporated into least cost rations or TMR's (total mixed rations).Table: By-product feedsFeedstuffPercent energy (TDN)Percent protein (CP)Alfalfa pellets6120Beet pulp (dry)7511Citrus pulp797 Corn gluten feed8022Corn stalks595Distillers grains (DDSG)9029 Ear corn829Grain screenings6514Kelp327Molasses (cane, dry)749Soybean Hulls7712Wheat middlings8219Whole cottonseed9523Vitamins and mineralsChoosing the right mineral supplement for sheep can be very tricky. Sheep require macro and micro (trace) minerals and you need to know which minerals are deficient (or excess) in your area, in your feedstuffs, and in your sheep's diet. Mineral supplements range from plain white salt to trace mineralized salt (TMS) to complete mineral mixes containing all of the macro and micro minerals required by sheep.In general, TMS fortified with selenium is all that is needed during the spring and summer when sheep are grazing high quality pastures containing more than 20 percent clover. Complete mineral mixes are recommended when sheep are consuming low quality forages. It is not necessary to offer minerals to sheep that are being fed complete feeds or TMRs.Studies have clearly shown that selenium supplementation for pregnant ewes via the feed is preferred to selenium injections in late gestation. When high grain diets, certain alternative feeds, or silage are fed to sheep, additional calcium may be need to be added to the diet.The most important minerals are calcium, phosphorus, salt (NaCl), and selenium.Table: Sources of calcium and phosphorusSourcePercent Calcium (Ca)Percent Phosphorus (P)Bone meal2412Dicalcium phosphate2518.5Limestone380Sodium phosphate022Alfalfa leaf meal2.880.34Kelp (dry)2.720.31Complete mineral mix18 to 208 to 10With the exception of salt, it has been scientifically proven that animals are unable to determine the proper balance and amount of minerals required when fed free choice. Some animals may consume more of what they do not need, while others may not consume enough (or any), even if they are required. It is therefore recommended, that minerals be thoroughly blended with the ration wherever possible to ensure proper supplementation. However if this is not possible, minerals can be mixed with loose salt.Granular or "loose" forms of minerals are preferred to blocks. Blocks are hard on the teeth and consumption may be less than optimal. Performance may be better if loose minerals are fed. Mineral feeders should be full of fresh mineral, placed in readily available areas and protected from the weather. Sporadic feeding of minerals may cause animals to "binge". Coccidiostats can be incorporated into mineral mixes.Sheep should not be fed commercial feeds and mineral mixes that have been formulated for other livestock because these products usually contain copper. While sheep have a dietary requirement for copper, they cannot tolerate excess copper in their diets. Excess copper is stored in the liver and can cause a toxic reaction, resulting in the death of the sheep.Copper nutrition is complicated, involving interactions with other minerals (antagonists), including molybdenum, sulfur, and iron. Producers should not provide supplemental copper to their sheep unless a deficiency has been documented via laboratory testing. The mineral status of animals can be determined by having their livers or kidneys analyzed.Feed AdditivesA feed additive is a compound added to the ration for a purpose other than to supply nutrients. Various feed additives can be utilized to improve the health of sheep and lambs.AntibioticsIn the US, oxytetraycline is FDA-approved to feed to ewes to prevent abortions caused by chlamydia and vibrio (Campylobacter spp.). In order to do so, producers must obtain a written script (called a VFD) from their veterinarian. Including sub-therapeutic antibiotics in the feed for lambs is now prohibited. IonophoresLasalocid (Bovatec®) and Monensin (Rumensin®) are ionophores that can be added to mineral mixes or complete rations. Ionophores improve feed utilization and gain in cattle by altering rumen fermentation. They are also coccidiostats. They kill coccidia, primarily during the sporozoite stage. Lasalocid (Bovatec®) is labeled as a coccidiostat for confined sheep.Rumensin® is approved for use in goats and cattle. Its use in sheep must be prescribed by a veterinarian. Care must be taken when having Rumensin® mixed into rations, as there is a greater risk of toxicity. Decoquinate (Deccox®) is another coccidiostat. Deccox® stops coccidia from growing. In contrast with Bovatec® and Rumensin®, Deccox® is a quinolone. It is safer to use than ionophores, but is more expensive. Bovatec® and especially Rumensin® can be toxic to equines. Feeding Bovatec® or Deccox® to ewes prior to lambing may help to reduce the level of coccidia in the lambing environment. Rumensin® fed to ewes during late gestation may help to prevent abortions caused by toxoplasmosis. Other potential benefits to ionophores include reduced incidences of acidosis and feed lot bloat. Ionophores have also been shown to reduce livestock methane production (CH4) and nitrogen leaching. Other feed additivesAmmonium chloride is often added to lamb rations to prevent urinary calculi (kidney stones). Ammonium chloride will help to acidify the urine. It should be added to the ration at a rate of 0.5 to 1.5 percent. It can also be mixed as a drench and used to treat lambs with early signs of urinary calculi. Probiotics are just the opposite of antibiotics. They are living organisms of beneficial bacteria. Probiotics may improve animal performance by keeping livestock healthy and improving their digestion. Many commercial feeds contain probiotics. Milk replacers usually contain probiotics.Other potential feed additives include essential oils, yeast, rumen buffers (e.g. sodium bicarbonate), and toxin binders (e.g. mycotoxins). Similar to probiotics, research regarding the potential benefit of yeast and essential oils is still pending.

SOME KEY POINTS Sheep should be fed rations that have been balanced for energy, protein, vitamins, and minerals. In order to properly balance rations, you need to know the weight, age, and stage and level of production. Nutrient requirements for sheep and lambs have been established by the National Resource Council (NRC). While feed composition tables provide the nutrient composition of many feedstuffs, forages (and by-product) feeds should be tested to determine their nutritive content. Rations an be balanced by hand (using simple math) or using a computer or smart device. A ration is the amount of feed that is fed to livestock during a 24-hour period. Sheep should be fed rations that have been properly balanced for energy, protein, minerals (especially calcium and phosphorus), and vitamins. If balanced rations are not fed, you may not be meeting the nutrient requirements of the sheep or lambs you are feeding or you may be exceeding their requirements. There are many potential consequences to not feeding sheep and lambs balanced rations. Ration balancing will also help to determine least-cost feeding options. There are five steps to balancing a ration. Describe the sheep you are feeding Look up their nutrient requirements Determine what feedstuffs are available List the composition of the feeds Balance the ration by hand or using a computer Step 1: Describe the animals you are feeding Sheep with different nutrient requirements need to be fed differently. A sheep's nutritional requirements are based on its age, size (weight), and stage and level of production. Lambs Lambs tend to have higher nutritional requirements because they are still growing. Early-weaned (younger) lambs have higher nutritional requirements than late-weaned (older) lambs. Lambs with high genetic potential for growth have higher nutritional needs than lambs with low to moderate genetic potential. Genetic potential is usually estimated by frame size. When nutrition is not a limiting factor, larger-framed breeds and lambs will usually grow faster than small-framed breeds and lambs. Forage alone does often not meet the nutritional requirements of fast growing lambs. Lambs and yearlings often need to be fed for both growth and production (gestation and lactation). Ewe lambs that will be lambing for the first time at 12 to 14 months of age should be fed separately from mature ewes. They don't necessarily need more feed, but they usually require a more nutrient dense diet (e.g. higher energy and protein). Size Size affects the level of nutrients that a sheep requires. Obviously, a 225-lb. Suffolk ewe requires more nutrients to maintain herself than a 110-lb. St. Croix ewe. All shepherds should have access to a set of scales. No one can accurately predict weights. Unfortunately, weigh tapes are not suitable for sheep, due to their varying coat types and lengths. Production A ewe's nutrient requirements change throughout her production cycle. They increase at the time of breeding and during her last six weeks of pregnancy and are highest during the first 6 to 8 weeks of lactation. Ewes carrying triplets have higher nutritional requirements than ewes carrying twins, and ewes carrying twins have higher nutritional requirements than ewes carrying singles. The more lambs a ewe is nursing the higher her nutritional requirements will be. While litter sizes are not usually known ahead of time (unless ewes are scanned for pregnancy determination and fetal numbers), most producers have a general idea of the reproductive rate of their flock and know which ewes usually give birth to multiple lambs. Step 2: Determine their nutrient requirements The nutrient requirements of sheep (and other animals) have been determined by the National Research Council (NRC). The requirements are updated periodically. The requirements for sheep (and other small ruminants) were most recently updated in 2007. Many publications and software programs still use the NRC requirements from 1985. Besides the NRC book, Nutrient Requirements of Small Ruminants, there are various other places where the nutrient requirements of sheep and lambs can be found. Many university facts sheets list nutrient requirements of sheep and lambs. The nutrition chapter of the Sheep Production Handbook has tables giving the nutrient requirements of different classes of sheep. Other books usually give abbreviated lists of nutrient requirements. Nutrient requirements are always given on a dry matter (DM) basis. Amounts need to be converted to an as-fed basis to determine how much to feed. Most common feeds are around 90 percent dry matter. Some feeds contain significantly more moisture, e.g. silage, haylage, balage, fresh forage and green chop, hydroponic fodder, and many byproduct feeds. Step 3: Determine what feedstuffs are available The availability of feedstuffs varies by geographic location, year, infrastructure, and individual farm. If a feed crop is grown or manufactured locally, it is more likely to be available as a livestock feed ingredient. In some years, growing conditions (e.g. drought) may limit the availability of a feedstuff or affect its quality. In livestock production areas, especially dairy areas, there are likely to be more feed stores, mills, and dealers, giving producers more feeding options. Remote areas and extreme climates often have few choices. In addition, just because a feedstuff is available doesn't mean a producer can use it. Small farms have many limitations. Many lack the equipment necessary to feed silage and round bales of hay or store bulk quantities of feed. Step 4: List the composition of the available feeds As with the nutrient requirements, there are several places to find and ways to determine the nutrient composition of different feedstuffs. Many of the same books that give nutrient requirements of livestock have feed composition tables, e.g. NRC's Nutrient Requirements of Small Ruminants and the Sheep Production Handbook. Colorado State University has a online fact sheet that provides feed composition tables for sheep and cattle. Beef Magazine also has feed composition tables that can be downloaded. The values found in feed composition tables are usually fairly accurate for feedstuffs that do not vary much in composition, e.g. grain and oilseeds. For feeds that vary significantly in nutrient composition, e.g. hay and by-product feeds, it is better if actual values are used. Any feedstuff can be analyzed at a forage testing laboratory. A forage test provides a wealth of information for a marginal cost. Some companies or government agencies may do forage testing for free. If commercial feeds are being fed, the nutrient composition of the feedstuff will be on its label. Feed labels usually give the percentage (sometimes minimum and maximum)of crude protein, crude fiber, crude fat, ADF (acid detergent fiber), calcium, and phosphorus, as well a list of the feed ingredients. Mineral mixes, blocks, or tubs will have a more extensive listing of vitamins and minerals. Step 5: Balance the ration Rations can be balanced by hand (using simple math), online, and using ration balancing software. No matter which method is used to balance the ration, the same information is required: a description of the animals, nutrient requirements of the animals, available feedstuffs, and composition of feeds. If rations are balanced online or ration-balancing software is used, nutrient requirements and feed inventories will be build into the programs. Programs usually allow the user to alter the nutrient requirements and feed compositions and add custom feeds. Balancing rations by hand Rations can be balanced by hand using paper, a pencil, and simple math. Step 1. Describe the animals Let's balance a ration for mature ewes that average about 155 lbs. They are nursing three-week old twin lambs. Step 2. Look up the ewes' nutritional requirements Table: Nutrient requirements for 155-lb. ewe nursing three-week old twins Source: Nutrient Requirements of Small Ruminants: Sheep, Goats, Cervids, and New World Camelids 2007 Step 3. Determine what feedstuffs are available. You have barley, a mixed clover- grass hay, and a commercial protein supplement. Step 4. List the composition of the available feeds Step 5. Balance the ration The easiest way to balance a ration is to start with the forage (usually hay). Determine how much hay you are feeding or how much hay they are consuming (if the hay is fed free choice). Be sure to factor in waste, as there can be considerable waste when feeding hay, particularly lower quality hays. Let's say you are feeding (they are eating) 5 lbs. of hay per day. Assume a 10 percent feeding loss. 5.0 lbs. fed - 10% percent = 4.5 lbs. of hay being consumed by an individual sheep You have to convert it to dry matter intake (DMI) in order to do further calculations. 4.5 lbs. fed ÷ 0.88 (% DM) = 4.0 lbs. of DM Determine how much nutrients the 4.0 lbs. of hay is providing. Energy: 4.0 x 0.58 (%TDN) = 2.3 lbs. of TDN Protein: 4.0 x 0.15 (% CP) = 0.6 lbs. of CP Calcium: 4.0 x 0.0084 (%Ca) = 0.0336 lbs. of Ca (or 15 g) Phosphorus: 4.0 x 0.0030 (%P) = 0.0124 lbs. of P (or 5.6 g) The ewes require 4.0 lbs. of TDN per day. 4.0 lbs. TDN (required) - 2.3 lbs. TDN (supplied by hay) = 1.7 lbs. TDN (deficiency). The grain portion of the ration needs to provide 1.7 lbs. of TDN to meet the 4.0-lb. requirement of the ewes. 1.7 lbs. ÷ 0.84 (%TDN of grain) = 2.0 lbs. of grain You need to convert to an as fed basis in order to know how much grain to feed 2.0 lbs. DM ÷ 0.89 = 2.25 lbs. As fed Next, you need to know how much protein the grain ration needs to provide. The hay is providing 0.6 lbs. of CP. The ewes require 0.92 lbs. 0.92 (required) - 0.6 (provided by hay) = 0.32 lbs. CP. (deficiency) 0.32 lbs. CP ÷ 2.0 lbs. of grain = 0.16 or 16%. The grain ration needs to be 16% protein. You can use Pearson's Square or the substitution method to determine the ratio of barley to commercial protein supplement. Pearson's Square Pearson's Square is an old mathematic tool that can be used to balance rations by blending two ingredients. The value in the middle of the square must be between the two ingredients that are to be mixed. Subtraction is done diagonally. Negative signs are ignored. This example shows Pearson's Square being used to determine the ratio of grain to supplement to create the 16% protein ration needed in our example. Pearson's Square shows that you need to mix 85 percent barley with 15 percent of the protein supplement to make a 16 percent protein grain ration for your lactating ewes. Similar calculations should be done to determine if the ration is meeting the calcium and phosphorus needs of the ewes. Earlier calculations show that the hay portion of the ration already meets the calcium requirements of the ewe. Balance rations using a computer Because the math is tedious, many sheep producers prefer to use a computer to balance sheep rations. There are several options. The Montana State University Sheep Ration Program is a free online program for balancing sheep rations. It has a feed inventory of over 300 forages and feeds. Feed specifications and rations are stored on MSU's server. Cornell University has set up a free Access database called Feedform to formulate diets based on the substitution method. Microsoft Access is required to run the program. There are several ration-balancing programs that can be purchased. ARIES is a package of computer programs developed by the University of California at Davis for formulating and analyzing rations for sheep. Oviration is a Canadian program that enables sheep farmers to formulate their own sheep nutrition program. The author of Sheep 201 has developed several Excel spreadsheets to assist sheep producers in feed management decisions. RationEvaluator allows the user to evaluate the current ration that is being fed. The ration can be balanced by changing composition of the ration, using the available feedstuffs. RationMixer can be used to batch mix rations. NutrientCosts allows users to compare the cost of different feedstuffs. There are many online versions of Pearson's Square. Pearson's Square has various other real-world applications. Making adjustments to balanced rations There are times when adjustments may need to be made to otherwise balanced feeding programs. You may wish to increase the feed intake of animals that are in poor body condition and likewise reduce the intake of obese sheep. These kind of feed adjustments should not be made during critical periods during the production cycle. For example, reducing the intake of a fat ewe during late gestation can cause her to develop pregnancy toxemia. Conversely, increasing the feed intake of a thin ewe during late gestation may increase the size of her unborn fetus(es), making the pending delivery more difficult. Activity can alter nutrient requirements. Livestock that have to travel farther for their food and water have higher nutritional requirements, as they expend more energy. For this reason, sheep on pasture have higher nutritional requirements than housed sheep. Weather and climate can have a significant effect on nutrient requirements. When it is cold, sheep require more energy to maintain their body temperature. Critical temperature is the lowest temperature or wind chill at which no additional energy is required to maintain core body temperature. There is a 1 percent increase in energy requirement for each 1°F that the temperature is below the sheep's critical temperature. A sheep's critical temperature depends upon the length of its fleece (and other factors). It is about 28°F (2°C) for a sheep with a 2.5 inch fleece and about 50°F (10°C) for a freshly shorn sheep. When don't we balance rations It is difficult to balance rations when sheep are free ranging on pasture. While you can determine the nutrient composition of fresh growing forage, it is difficult to determine intake, especially in a mixed sward. When sheep are grazing, they are usually given free choice access to a trace mineral mix to make sure their mineral and vitamin requirements are being met. It's similar to people taking vitamins or other supplements. When forage quality is low, protein tubs or blocks are sometimes provided. It is estimated that sheep will consume 2 to 4 ounces per day of a poured nutritional product. Monitoring body condition of grazing animals is a good way to determine if their nutritional needs are being met by the forage. Poor body condition is an indication that supplementation is advisable.

SOME KEY POINTSHow much you need to feed a ewe depends upon her age, weight and body condition, along with her stage and level of production.A wide variety of feedstuffs can meet a ewe's nutritional requirements.Pregnancy toxemia is a common metabolic disease of ewes caused by an insufficient intake of energy during late pregnancy.A ewe's highest nutritional requirements are during early lactation.Body condition score should be done at key points in the ewe's production cycle to make sure she meets specific targets, e.g., BCS 3 or better at the time of breeding and lambing.Feed usually represents the single largest cost in all types of sheep production. A ewe's nutritional needs are not static. What and how much to feed a ewe depends upon many factors, including the ewe's age, weight, and body condition, along with her stage and level of production. Climate, exercise, and disease can also have an effect on her nutritional requirements.A wide variety of feedstuffs can meet the nutritional needs of ewes during their different production stages. There is no one perfect feeding program. The choice of feeding program will depend upon geographic region, when lambs are born, and the cost and availability of feedstuffs.Life cycle feeding of ewes BreedingFlushingFeeding the ewe so she is gaining weight about 2 weeks before breeding is called flushing. Flushing may increase lambing percentage by increasing the number of eggs that the ewe ovulates. Flushing works best on thin ewes (BCS < 2.5). Ewes that are already in good body condition (BCS > 3) usually do not respond well to flushing.Flushing has more effect early in the breeding season. Flushing may also be beneficial late in the breeding season. Mature ewes respond better to flushing than yearlings. You can flush ewes by feeding them 0.5 to 1 lb. of grain per day or by moving them to a better quality pasture. If flushing is continued through the breeding season, it may enhance embryo survival during early pregnancy.Plant estrogensEwes should not be bred on pastures that contain a high percentage of legumes. Clovers (especially red clover), alfalfa, and birdsfoot trefoil may delay estrus. Fescue grasses, as well as barley grain and oat grain also contain compounds with estrogenic activity. Estrogenic compounds are present in varying concentrations in most all legume plants during the entire growing season, though not when the plants are mature and dry. Mixed pasture swards dilute the effects of specific plants.Early-to-mid gestationEarly to mid gestation is a critical period in the ewe's production cycle because placental development occurs from day 30 to day 90 of gestation. Placental size or weight affects nutrient transfer between the ewe and the her fetuses. Underdeveloped placentas result in lower birth weights regardless of late gestation nutrition. While the ewe's nutritional requirements during this period are not significantly above maintenance requirements, 21 days of severe underfeeding or 80 days of moderate underfeeding can affect placental development.Late gestationGood nutrition during late gestation will help to ensure a successful lambing season. Knowing how much to feed ewes during late gestation can be difficult because it depends upon the number of fetuses the ewe is carrying. Underfeeding will result in the birth of small lambs. Small lambs are less resistant to cold stress and will have slower pre-weaning growth. Most of the ewe's mammary development occurs during late gestation. Underfeeding will reduce the yield and quality of milk, including colostrum. Overfeeding can result in oversized fetuses. Big lambs increase lambing problems and have a higher mortality rate.The nutrients that are important during late gestation are energy, protein, calcium, selenium, and vitamin E. The amount of energy required depends upon the number of fetuses the ewe is carrying. Cold stress increases nutritional requirements, especially if ewes are kept outside. Winter lambing ewes usually cannot consume enough forage to meet their energy needs. More energy is required two weeks before lambing versus six weeks before lambing. Ewes carrying singles do not need to receive grain as early as those carrying multiple births.Pregnancy toxemiaPregnancy toxemia (ketosis or twin lamb disease) is a common disease of sheep in late gestation. It is caused by an inadequate intake of energy during late gestation, as fetuses make 70 percent of their growth during this period. As the ewe breaks down her body fat to meet her increasing nutritional needs, toxic ketone bodies are produced.The ewes that are most prone to pregnancy toxemia are fat ewes, thin ewes, old ewes, timid ewes, and ewes carrying multiple births. Treatment is aimed at increasing blood glucose level. In advanced cases, a caesarian section may be necessary.Milk feverMilk fever is different in sheep as compared to dairy cattle in that symptoms occur pre-lambing. Milk fever is low blood calcium (hypocalcemia). It is caused by either inadequate intake of calcium (usually) or the inability to mobilize calcium reserves. The clinical signs of milk fever are very similar to pregnancy toxemia. Differential diagnosis is based on the affected ewe's response to calcium therapy.Vaginal prolapses tend to occur more frequently in fat ewes or ewe lambs carrying multiple fetuses. There is simply not enough room for everything. . Preventing ewes from becoming overfat and limiting intake are two ways to reduce vaginal prolapses.LactationLactation places the greatest nutritional demand on ewes. How much you feed a ewe will depend upon how many lambs she is nursing, her size and condition, her age, and the time of the year the lambs are born. Ideally, ewes should be separated into production groups and fed according to the number of lambs they are nursing. A general rule of thumb for concentrate feeding of lactating ewes is 1 pound of grain for each lamb nursing the ewe. On pasture, ewes rearing triplets should be given access to more forage. Supplemental feeding may be advisable.Protein and energy are both critical nutrients for milk production. If either nutrient is fed below the requirement, milk yields and lamb gain will be reduced. After the first 60 days of lactation, you should reduce the amount of feed you are feeding because all it will accomplish is making the ewes fat.Most ewes will lose weight during lactation. Weight loss during lactation affects protein requirements. The more weight ewes lose, the higher their protein requirement will be.Water Lactating ewes require a lot of water if they are expected to milk well. It is estimated that lactating ewes require 100 percent more water than non-lactating ewes. Ewes should have a free-choice supply of fresh, clean water at all times. Heated water bowls should be used during the winter to encourage water consumption. Water bowls should be checked and cleaned on a daily basis.WeaningWeaning often takes place at a time when ewes are still producing a lot of milk. In this is the case, grain should be reduced 1 to 2 weeks prior to weaning. For the last week or so prior to weaning, no grain should be fed to the ewes. For the last several days before weaning, ewes should be fed a low quality grass hay or straw. After the lambs have been weaned, the ewes should be maintained in dry lot and fed low quality grass hay or straw until their udders start to dry up and recede.It is not necessary to remove water from ewes at weaning. It can also be dangerous during hot weather. Do not turn ewes onto pasture immediately after weaning. Spring grass is high in protein, water, and other nutrients which promote milk production.The overriding concern at weaning time for ewes is to prevent mastitis. Ewes need to be watched closely during the weaning period for mastitis. Ewes with spoiled udders have decreased or no future production value.MaintenanceIn annual lambing systems, maintenance is the longest period in the ewe's production year. Maintenance means the ewe only needs to maintain her body weight or have slow growth to recover the weight (condition) she lost during lactation. A wide variety of low-cost feedstuffs can meet the maintenance requirements of ewes. Pasture or grass hay is all most sheep need to maintain themselves. Pet sheep or wethers raised for wool should always be fed at a maintenance level.Body condition scoringBody condition scoring is a valuable management tool that can be used to evaluate the feeding program and the need for changes. Since there is a wide variation in weight, body condition is usually better indicator of condition than weighing.A body condition score estimates condition of fat and muscle. Both the vertical bone protrusion (spinous process) and horizontal protrusion (transverse process) of the loin are felt and used to access body condition scoring. It is a subjective score. The exact score is not as important as the relative scores and differences between scores.The system most widely used in the US uses a scale of 1 to 5, with 1 being an emaciated sheep, 3 being a sheep in average condition, and 5 being an obese sheep. Half scores are commonly used. On average, 1 condition score is equal to about 13 percent of the live weight of a ewe at a moderate condition score of 3 to 3.5.Most sheep have body condition scores between 2 and 4. A ewe's body condition score will change throughout her production cycle. The three most important times to body condition score ewes are prior to breeding, late gestation, and weaning.Table: Body condition scoringBCS 1EmaciatedSpinous processes are sharp and prominent.Transverse processes are sharp; one can pass fingers under ends. It is possible to feel between each process.Loin muscle is shallow with no fat cover.BCS 2ThinSpinous processes are sharp and prominent. Transverse processes are smooth and slightly rounded. It is possible to pass fingers under the ends of the transverse processes with a little pressure. Loin muscle has little fat cover, but is full.BCS 3AverageSpinous processes are smooth. Transverse processes are smooth and well covered, and firm pressure is needed to feel over the ends. Loin muscle is full with some fat cover.BCS 4FatSpinous processes can be detected only with pressure as a hard line. Transverse processes cannot be felt. Loin muscle is full with thick fat cover.BCS 5ObeseSpinous processes cannot be detected. Transverse processes cannot be detected. Loin muscle is very full with very thick fat cover.Source: Body condition scoring of sheep, Oregon State University (1994, archived)Generally, the better the body condition score is at mating, the higher the ovulation rate will be. However, ewes with body scores over 4 tend to have a higher incidence of being barren. Ewes that have a body condition score of less than 3 at mating will respond better to flushing. Ewes with body condition scores of 3 and 4 at lambing tend to lose fewer lambs and wean more pounds of lambs than ewes with body condition scores of 2.5 or less. A ewe should be at her highest condition score on the day she lambs. This is critical since she is entering her highest nutritional demand. Thin ewes are not able to produce as much or as high quality colostrum as ewes in better condition. Thin ewes do not milk as much as well condition ewes.It is also important to body condition score rams. As with the ewes, thin or fat rams often do not get the job done.

SOME KEY POINTS For the first several weeks of life, all a lamb needs is its mother's milk. A ewe's milk production peaks at 3 to 4 weeks. Creep feeding is a means of supplying extra nutrition (usually grain) to nursing lambs. It is beneficial to provide creep feed to lambs in intensive production systems. There are pros and cons to different methods of feeding lambs. There are different ways to feed lambs, many ways. One method is not better than another. There are pros and cons associated with each feeding program and production system. The appropriate feeding program is usually affected by geographic location, type of production system, marketing options, and cost and availability of feed. Lambs born in the winter are often creep-fed and finished on high concentrate diets, whereas lambs born later in the season (spring) are often placed on pasture (or range) with their dams. Many feeding programs utilize both pasture and grain. For the first several weeks of life, all a lamb needs for nourishment is its mother's milk. Lambs will start to nibble on solid food soon after birth. A ewe's milk production peaks between 3 and 4 weeks of lactation. By the time lambs are 4 to 6 weeks old, they may be obtaining as much as 50 percent of their nutrient intake from sources other than their mother's milk. Creep feeding Creep feeding is a means of supplying extra nutrition, usually grain, to nursing lambs. It is especially beneficial for lambs managed in intensive production systems in which early weaning is practiced. Creep feeding is also advantageous for flocks which have a lot of multiple births or in flocks where milk production is a limiting factor. It is more efficient to feed the lamb directly than to feed the ewes for milk production. Creep feeding is usually of less value for lambs that will be developed on pasture in the spring and summer. Creep feeding may not be cost-effective in all production systems. Lambs should be started on creep feed as soon after birth as possible, though they will not eat significant amounts of feed until they are at least three to four weeks old. Providing early access to creep feed gets lambs in the habit of eating dry feed and helps stimulate development of their rumens. It reduces the stress of early weaning (< 60 days). Creep pen Lambs gain access to creep feed through a opening in a fence or gate. The opening must be large enough for the lambs to get through, but too small for the ewes, especially the thin ones, to enter. It is best that creep gates have multiple openings so the lambs do not think they are trapped. Ideally, the lambs should have access to the creep area from multiple sides. Creep gates can be home made or purchased. An inexpensive creep gate can be made by cutting a hole in a livestock panel. Feeders used in the creep area should be designed so that lambs cannot stand or play in them. The creep pen should be placed in a high traffic area where lambs will naturally find their way to it. A sunny spot in the barn is an ideal place to place the creep. A light will help to attract lambs at night. In addition to providing creep feed, the creep area is a place for lambs to loiter and sleep. It should be kept dry and well-bedded. Two square feet of space per lamb is recommended for the creep area. Each lamb should be allocated 2 inches of feeder space. Water should be available in the creep area, as well as high quality hay. Creep feeders can also be set up on pasture. Creep ration The creep ration does not need to be complex or expensive. At a young age, lambs prefer feeds that are finely ground and have a small particle size. Feeds that have high palatability for lambs include soybean meal, ground or cracked corn, and alfalfa hay. Some producers start lambs out on soybean meal. It is expensive, but the lambs do not eat much at an early age. Crumbled or textured rations are consumed better than pelleted creep feeds. Some producers use the same feed that they feed their ewes. The feed should be fresh and dry and should never be allowed to run out. High protein Because the growth of young lambs is mostly lean muscle (protein) rather than fat, protein supply is critical. The creep ration should contain 18 to 20 percent crude protein (at least 16 percent). The protein in creep feed should be all natural; urea should not be fed to young lambs. As lambs get older, they prefer coarser diets and whole grains. Older lambs deposit more fat, thus their requirement for protein diminishes. Calcium and phosphorus The creep feed should contain a calcium to phosphorus ratio of at least 2:1 to prevent urinary calculi (kidney stones) in male lambs, especially wethers. Inclusion of 1% feed grade limestone will also help to prevent urinary calculi. as a preventative for urinary calculi. Ammonium chloride is a urine acidifyer that is often added to lamb rations. Forage in the ration will also help to prevent formation of kidney stones. Additives The creep feed should contain a coccidiostat to prevent coccidiosis, a protozoan infection that causes scours (diarrhea) and production loss. Deccox® (decoquinate) and Bovatec® (lasalocid) are both FDA-approved as coccidiostats for lambs (in confinement). Rumensin® (monensin) is another coccidiostat, but it is not FDA-approved for lambs. Lambs should be vaccinated with Clostridium perfringins C & D. There may be some benefit to mixing probiotics or essential oils into lamb rations; research is pending. Feeding lambs from weaning to market Feed lot finishing of lambs Creep-fed lambs are commonly weaned early (< 90 days) and placed on high concentrate diets for finishing. Pasture-reared lambs must be brought gradually from a high roughage-low concentrate diet to a high concentrate-low roughage diet. This transition should take place over several weeks. When finishing lambs on high grain diets, acidosis, enterotoxemia, and urinary calculi can all be potential problems. Acidosis can be prevented by including at least 10 percent roughage in the diet, by feeding a rumen buffer (e.g. sodium bicarbonate), and by avoiding sudden changes in the type or amount of ration fed. Urinary calculi can be prevented by having a Ca:P ratio of at last 2:1, having a salt/mineral mix available free choice, and by feeding an urine acidifier like ammonium chloride. Getting lambs to drink plenty of water will also help to prevent urinary calculi. Lambs fed concentrate diets should be vaccinated twice for overeating disease. Corn and soybean meal commonly form the basis of these feed lot diets. However, other grains and protein sources can replace all or part of the corn and soybean meal in the diet, depending upon availability and cost. The energy value of barley and grain sorghum (milo) relative to corn is 90 percent. Both can replace 100 percent of the corn in the diet. Due to its higher fiber content, oats have only 80 percent of the energy value of corn. Wheat is equal to corn, but should not replace more than 50 percent of the corn or barley in the diet. Soy hull pellets can also form a significant portion of the feed lot diet. Alternative feeds Alternative sources of protein include Whole cottonseed, cottonseed meal and peanut meal. Urea (the end product of nitrogen metabolism) has a crude protein equivalent of 281 percent and can supply up to one-third of the nitrogen in the diet (of older lambs). To determine the pounds of nitrogen in the diet, you multiply the total pounds of crude protein in the diet by 16 percent. The decision to use other feeds should be based on their availability and cost relative to corn and soybean meal. To determine if other feeds are a better value than corn and/or soybean meal, comparisons must be based on the cost per unit of nutrient (protein and energy). Differences in weight and nutrient content need to be factored into these calculations. Whole grain feeding Whole-grain feeding of lambs improves feed efficiency, increases average daily gain, and lowers overall feed costs per pound of gain. It is usually the most profitable feeding program that can be used for grain-based finishing of feedlot lambs. Whole-grain diets consist of whole (unprocessed) grains, such as shelled corn or barley, mixed with a pelleted protein-vitamin-mineral supplement. With whole grain diets, it is usually not necessary to incorporate roughage (hay) into the diet or to supplemented it on the side. Consequently, whole-grain diets are high in energy and promote accelerated lamb gains. The feeding of whole grain provides lambs with a built-in "roughage factor." Only about one-third of the grain is cracked when first eaten by lambs. The remainder of the grain must be regurgitated during rumination for further mastication. This action of regurgitation and chewing contributes more saliva to the digestive process, thus increasing the buffering capacity of the rumen. Feeds containing processed grains must have roughage added to the grain mix or supplemented on the side to maintain proper rumen function and prevent digestive disorders. Pelleted supplements for whole-grain feeding are commercially available and are formulated to contain the additional protein, vitamins, and minerals required by lambs. When commercial supplements are not available, a custom pelleted supplement can be prepared. Because feed grains are low in calcium, it is critical that pelleted supplements contain additional calcium as a preventive for urinary calculi. Ammonium chloride or ammonium sulfate can be added to the pelleted supplement at a rate equivalent to 0.5% of the complete feed as additional insurance for the prevention of urinary calculi. Self-feeding vs. hand feeding In a self-feeding situation, lambs have feed in front of them at all times. With hand (or limit) feeding, a set amount of grain is fed twice per day at approximately the same time each day. There are pros and cons to each feeding system. Lambs that are self-fed will consume more feed and gain faster. Lambs that are hand-fed tend to make more efficient gains. It is easier to monitor animal health when lambs are hand-fed. Hand feeding requires more feeder space per lamb (9-12 inches vs. 1-2 inches). Hand-feeding requires more labor, so it is less common with larger lamb feeding operations, though hand-feeding can be automated. Regardless of the feeding program, abrupt changes to the ration should never be made. Self-feeders should not be allowed to run out. Feed additives Ionophores are often added to the feed lot diet to improve lamb health. Antibiotics can no longer be fed to lambs. Ionophores (Deccox® and Bovatec®) are used to control coccidiosis in feed lot lambs. The use of both has been shown to improve lamb average daily gain and feed efficiency. Probiotics Probiotics are the opposite of antibiotics. They are living organisms of beneficial bacteria. Yeast is a probiotic. Probiotics are also found naturally in fermented foods like yogurt with live cultures. Probiotics may improve animal performance by keeping livestock healthier and improving their digestion. Many commercial feeds contain probiotics. Milk replacers usually contain probiotics. There is limited research to attest to the benefits of probiotics in lamb diets. Recent research with meat goats showed no benefit to including probiotics in the diets of healthy growing kids. Implanting Though not a standard practice, implanting lambs with Ralgro® to improve growth rate is FDA-approved. Ralgro® is not a hormone or steroid. It is a plant extract (zeranol) that causes estrogen-like activity. Ralgro® is a pellet that is injected subcutaneously into the lamb's ear. Lambs may be implanted more than once and may be marketed 40 days following injection of the last implant. The cost of a single implant is less than 75 cents. Implanted lambs tend to grow faster, be more efficient in their feed utilization, and produce heavier carcasses. Implanting produces various physiological changes in the lamb. It reduces the weight of the testicles in ram lambs and makes pelt removal during slaughter easier (an added benefit). Implanting causes increased bone mineralization or bone maturity and can result in older lambs being wrongly graded as mutton. Ewe lambs should probably not be implanted, especially if they will be kept for breeding. Implanting has been implicated as a contributing factor to rectal prolapses. Pasture finishing of lambs Though pasture-fed lambs will usually not grow as fast as lambs fed concentrate diets, pasture rearing can be more economical. It is a more natural feed and environment for lambs. There seems to be a growing consumer demand for grass-fed animal products, due to the perceived health benefits. Grass-fed meat and milk tends to be lower in fat and higher in conjugated linoleic acid (CLA), vitamin E, omega-3 fatty acids, beta-carotene, and vitamin E than the meat and milk from grain-fed livestock. Regardless of diet, lamb is one of the best sources of CLA. Excellent pasture and grazing management is generally required to finish lambs on pasture. Lamb growth rates can vary greatly, depending upon the type and quality of pasture being grazed. As pasture quality declines, lamb gains decline. Rotational grazing systems which result in lambs consuming plants in a vegetative state when they are the most nutritious and palatable, will produce the best pasture gains. Pastures containing legumes usually produce better gains than those containing grass alone. The inclusion of warm season grasses into the pasture system may improve summer gains, as cool season grasses don't grow much during the summer months. Legumes will also improve summer growth of pastures. Lambs grazing "novel endophyte" (MaxQ™) or non-toxic endophyte strains of tall fescue can be expected to gain better than those grazing infected fescue varieties. The initial grazing trials with MaxQ™ tall fescue were done with lambs. Lambs grazing Max Q™ or endophyte-free tall fescue gained 0.37 lbs. per day vs. lambs grazing endophyte-infected fall fescue, which gained only 0.22 lbs. per day. Over a typical May to September grazing season, lambs tend to gain about one-third of a pound per day on traditional cool season pastures (Pennsylvania, West Virginia, and Maryland data). Internal parasites Internal parasites (gastro-intestinal worms) can have a significant effect on the health, welfare, and performance of grazing lambs. Traditional rotational and intensive grazing systems may exacerbate internal parasite problems, if pasture rest periods are not sufficient. In the past, it was advocated that grazing lambs be dewormed every three to four weeks during the grazing season. This practice has contributed to the widespread emergence of drug-resistance worms, making parasite control with anthelmintics more difficult and costly. Effective internal parasite control requires an integrated approach that combines appropriate pasture and animal management strategies with selective and/or targeted use of anthelmintics. Some forages have anthelmintic-like activity (e.g. sericea lespedeza, birdsfoot trefoil, and chicory) and can be incorporated into a pasture and grazing program. In 2019, BioWorma® became available in the US. BioWorma® contains a nematode-trapping fungus called Duddingtonia flagrans. It is a feed-through product that reduces pasture infectivity. While coccidiosis is generally considered to be more of a problem with confined lambs, outbreaks can occur on pasture, especially with intensive grazing programs, where more lambs are concentrated on a smaller land area. In fact, any place where livestock congregate can be a potential source of infection: laneways, sheltering areas, watering areas, feeding areas. A coccidiostat (Bovatec® or Deccox®) in the mineral mix will help to prevent outbreaks of coccidiosis. Lambs can also be given anti-coccidia drugs in drenches. Predators Grazing lambs are more susceptible to predation than those raised in confinement or drylot. Predator control begins with a good fence. Various management strategies can reduce the risk of predation, e.g. shed lambing and night penning. The use of livestock guardians (guardian dogs, llamas, or donkeys) has proven effective on many farms and ranches. Lethal control methods (shooting, trapping, toxic collars) may be necessary in some circumstances. Supplementation on pasture Pasture gains can be improved with supplementation. Supplementation makes the most sense when pasture quality is low. Supplementation will also help to stretch the pasture resource and/or allow increased stocking rates. Supplementation offers some of the same advantages as feed lot feeding, but without diminishing the benefits of a pasture diet. Supplementation may or may not be cost-effective. Most of the research done with pasture supplementation has been done with cattle. Some has been done with lambs in Europe and New Zealand. It is usually suggested that livestock be fed no more than 1% of their body weight in supplement. Research with cattle suggests that supplementation with feedstuffs that are high in starch, such as grain, reduces forage digestibility, as compared to energy supplements with highly digestible fiber sources (soybean hulls, corn gluten meal). Table: A comparison of grain vs. pasture-finishing of lambs

SOME KEY POINTS Pasture is the most natural diet for sheep and lambs and often all that is required. Cool season plants form the basis for most pastures used for sheep. Legumes fix nitrogen and are usually higher in protein that grasses. Warm season grasses do most of the growing during the summer months; most are native species. Sheep show a preference for forbs: broad-leaf, non-woody flowering plants like clover and weeds The pasture (or range) resource is often the most neglected part of the sheep enterprise, yet it usually provides the majority of nutrients to the stock. Pasture that is properly managed has the potential to minimize feed costs and increase profits. Pasture is the most natural diet for sheep and other ruminant animals. Though pasture is not without its own risks, fewer digestive problems are usually encountered when sheep and lambs spend the majority of their time grazing. Pasture plants A pasture can be comprised of many different kinds of plants. Which species to plant depends upon the purpose of the pasture, the climate, and soil type. Soil survey maps can help with the latter. The best pastures usually contain a mixture of grasses and legumes. Commercial pasture mixes usually contain several grass and legumes and sometimes forbs. Cool season grasses In many climates, cool season grasses form the basis of most sheep pastures. Cool season grasses are annual or perennial plants that begin growth during the fall or winter and grow to spring or early summer. Cool season grasses are not damaged by sub-freezing temperatures. However, they go mostly dormant during hot weather. Common cool season grasses include orchardgrass, Kentucky bluegrass, tall fescue, timothy, reed canarygrass, ryegrass, brome grasses, and wheat grasses. Tall fescue Tall fescue is the most important cool season grass in the United States. Most tall fescue is infected with a fungal endophyte that reduces performance in grazing animals and causes reproductive problems in horses. Sheep appear to be less affected by the endophyte than cattle and horses. Animal performance is superior on endophyte-free fescue, but plant persistence suffers. MaxQ™ tall fescue contains a non-toxic endophyte which improves animal performance while maintaining plant performance. Tall fescue is the most desirable grass to stockpile for late fall and winter grazing. Unlike the summer forage, fall-saved fescue is palatable and high in digestibility. Forage quality losses after frost are less for fescue than other forages. Endophyte toxicity of stockpiled fescue declines with time. Legumes Legume plants are known for their ability to fix atmospheric nitrogen. Legumes have a higher protein content than grasses. They fall into two classes: forage and grain. Forage legumes include alfalfa, clovers, birdsfoot trefoil, lespedezas, Sunn hemp, and vetch. Grain legumes include beans, peas, lupins, kudzu, and peanuts. Pasture legumes improve summer pasture productivity. Legume pastures (alfalfa and clover) are also a common cause of bloat. The phytoestrogens contained in some pasture legumes (e.g. red clover) can cause a decline in ewe fertility. Newer cultivars have greatly reduced this risk. Sericea lespedeza The high tannin content of sericea lespedeza gives it an antiparasitic effect. Fecal egg counts tend to be lower among small ruminants grazing sericea lespedeza pastures, as adult worms lay fewer eggs and the eggs that are produced have reduced hatching ability. Though it shows great promise for helping to control internal parasites in sheep and goats, sericea lespedeza is classified as a noxious weed in some states. Warm season grasses Warm season grasses are annual or perennial plants that begin growth during the spring, and grow to summer or fall until frost. Common warm season grasses include bahiagrass, bermuda grass, crabgrass, eastern gamagrass, big bluestem, indiangrass, switchgrass, sudangrass, and pearl millet. Most native grasses are warm season grasses. Sheep have generally not performed as well on warm season grasses as cattle. Warm season annuals are usually favored for sheep. Annuals An annual is a plant that completes its life cycle in one year. Annuals must be planted every year in order to produce forage for livestock feed. Summer annuals complete their life cycle between spring and fall. Summer annuals include crabgrass, pearl millet, sorghum, sudangrass, and sorghum x sudangrass. Winter annuals complete their life cycle between fall and spring. Winter annuals include wheat, barley, winter oats, rye, and triticale (rye x wheat). Brassicas Brassicas are annual crops which can be grazed by sheep. They include rape, kale, swede, and turnips. They are most commonly used to extend the grazing season. Performance on brassicas is improved if dry hay is offered. Lamb performance on brassicas varies. Small grains When properly managed, small grain crops can be used for grazing by sheep and other livestock. Small grains can provide excellent pasture in the fall and early spring. The effect of livestock grazing on small grain yields ranges from yield reductions to increases in yield. Forbs Forbs are non-grasslike, non-woody, flowering herbaceous plants. Forbs are commonly called weeds. They may be classified as annual or perennial, warm season or cool season. When grazing a mixed sward, sheep prefer forbs. Sheep's preference for forbs makes them well-suited to landscape management. Browse Browse includes buds, twigs, leaves, fruit and flowers of woody plants (trees and shrubs). While sheep will eat various browse species, goats are best known for choosing these types of plants. Crop residues Crop residues are the materials left in a field after the crop has been harvested. Residues include stalks and stubble, leaves, and seed pods. Crop residues offer a low-cost feeding alternative for sheep, while sheep grazing helps to control pests by disrupting insect life cycles. Pasture Establishment Planning for a successful pasture establishment should begin months in advance. It can take years to correct severe soil acidity. If lime is needed, it should be applied six to 12 months prior to seeding. Different seeding methods can be used to establish a pasture: drilling, cultipacking, and broadcasting. No-tillage involves using herbicides to kill the existing vegetation and then seeding directly into the residue. The seed bed is usually prepared by hay removal or hard grazing The best time to establish cool season grasses is in the late summer and early fall. Spring plantings have enough moisture for seed germination, but weed pressure is high. Warm season grasses should be planted in late spring to early summer after the soil temperature has reached 65°F or above. Seeding rates depend upon the plant species and seeding method. Certified seed is recommended. Legume seed may need to be inoculated with the proper bacterial strain. New seedings should not be grazed until the plants have developed sufficient root systems. If you can easily pull a plant from the ground, its root system is not sufficiently developed. Pasture Renovation Pasture renovation is when you "renew" a pasture by introducing a desired forage species into the existing plant stand. It should be done on a regular basis, as most legumes tend to be short-lived in a pasture. Overgrazing, poor fertility, and other adverse conditions tend to favor grass plants over legumes. Frost seeding is a common method of pasture renovation. This is when seed is broadcast into existing pastures during the late winter or early spring when the soil freezes at night, but thaws during the day. Pasture Maintenance Maintaining a pasture is similar to maintaining a car. If you want good, long-term performance of your pasture, you need to take steps to properly maintain it. Soil sampling a minimum of every three years is a must. Lime and fertilizer should be applied according to soil test results. Excess lime can cause mineral deficiencies. Excess fertilizer pollutes ground water. Pastures which are composed of predominantly grass plants should receive nitrogen fertilizer every year. There are numerous sources of inorganic and organic nitrogen. Sheep grazing pastures fertilized with poultry litter or pig manure may be at increased risk for copper toxicity. Pasture which contain 30 percent or more legumes usually do not require nitrogen fertilization. Broadleaf weeds can be controlled with herbicides and mowing. Controlled grazing and proper soil pH will also help to suppress weed growth. Poisonous plants Numerous plants can be poisonous to sheep. Toxicity usually depends upon the growing conditions and stage, plant part, and amount consumed. As a general rule, sheep usually avoid poisonous plants. Problems arise when desirable forages are scarce and poisonous plants are abundant. The effects produced by the ingestion of poisonous plants are extremely variable and depend upon the poison consumed in the plant. Some poisonous plants cause rapid death. Others produce gastro-enteritis or cause nervous symptoms or locomotion problems. Treatment is usually unrewarding.

SOME KEY POINTS Continuous grazing is usually not recommended because it results in poor forage quality and quantity and lack of flexibility in controlling parasites. Rotational grazing features periods of grazing and rest and usually results in better forage utilization. Intensive (rotational) grazing is when animals are moved frequently to new paddocks. It usually results in the greatest production of forage. Frequent rotations (< 4 days) and long rest periods (> 30 days) are usually necessary to control internal parasitism, especially in lambs. There are numerous advantages to mixed or multispecies grazing with cattle or horses. Grazing management is how and when you control the grazing habits of the animals on your pastures. What animals, how, when, and for how long they graze a pasture determines the species make-up of the pasture and its long term viability, how much forage it yields, and how well the animals perform. Overgrazing and undergrazing pastures is detrimental to both plant and animal health, as well as soil and water quality. Continuous grazing Continuous grazing is a one-pasture system in which livestock have unrestricted access to the pasture area throughout the grazing season. It is a simple system to implement and manage, with minimal capital investment and movement of animals. If sufficient forage is available, continuous grazing often results in a higher individual animal performance than other grazing systems. However, continuous grazing usually results in poorer forage quality and quantity. Pastures are usually grazed unevenly by livestock, as livestock overgraze the plants they like and undergraze the plants they don't like. Manure is also distributed unevenly. Stocking rates are usually lower, so the land is less productive. Weeds and other undesirable plants usually persist. Parasites can be a problem if stocking rates are too high. Controlled grazing Controlled grazing gives the producer more control over grazing animals. It has many different names and variations. Simple rotational grazing Simple rotational grazing is a pasture system in which more than one pasture area is used and livestock are moved to different pasture areas during the grazing season. Pastures need rest periods to recover from grazing and allow plants to regrow. The longer a pasture rests, the less infected it will be with worm larvae. Simple rotational grazing usually increases forage yields and quality. Stocking rates can usually be increased. Weed control is better. On the other hand, fencing costs are higher than with continuous grazing. Unless a central laneway system is utilized, each paddock needs to have water access. In some climates, the animals should have access to shelter (shade) in each paddock. Intensive rotational grazing Intensive rotational grazing is a system with many pastures, oftentimes called paddocks or cells. Livestock are moved from paddock to paddock based on forage growth and utilization. The number of paddocks and frequency of rotation depends upon many factors, including the class of livestock and production goals of the manager. After 3 days, livestock will start to graze regrowth of plant material. It is usually recommended that livestock be rotated every 3 to 7 days to a new paddock. Intensive rotational grazing usually results in the highest forage output per acre (or hectare). Stocking rates can typically be increased over those utilized in a continuous or simple rotational grazing system. Manure is more evenly distributed in paddocks. Weed control is better, as animals are usually forced to eat everything in a paddock. Intensive rotational grazing requires a higher degree of management and skill. This is why it is often called "management-intensive grazing." Initial costs will be higher due to fencing materials and water distribution systems. Providing water and shelter (shade) in each paddock can be a challenge. Intensive rotational grazing could exacerbate internal parasitism in sheep and lambs, if pastures are grazed for too long or pasture rest periods do not allow for sufficient die-off of infective parasite larvae. Strip grazing Strip grazing is a grazing management system that involves giving livestock a fresh allocation of pasture each day. It is usually organized within a paddock grazing system and the animals are controlled by the use of an electric fence. Creep grazing Creep grazing is when young nursing animals are given forward access to fresh, ungrazed pasture through an opening in the fence. To be effective, the forage in the creep area must be superior to the forage in the non-creep area. The greater the difference between forage in the two areas, the greater benefit to creep grazing. In addition to better nutrition in the fresh paddocks, infection with infective worm larvae will be lower. Year-round grazing Year-round grazing is possible even in cold climates, though extending the grazing system is probably a more realistic goal for most producers. Tall fescue is the best grass to stockpile for winter grazing. Small grains, root crops, and crop aftermaths are other options for extending the grazing season. Warm season grasses can improve forage availability in the summer, when many cool season plants go dormant. Mixed species grazing Mixed species grazing is when two or more species of domestic animals are grazed together or separately on the same grazing area in the same grazing season. The rationale for mixed species grazing is based on the principle that animals have different grazing preferences and dietary overlap is minimal in a diverse sward. An additional benefit to mixed species grazing is parasite control. Sheep, cattle, and horses are generally affected by different gastro-intestinal parasites, whereas sheep, goats, and camelids share the same parasites. Table: Diet preferences of different livestock Targeted or prescribed grazing Prescribed grazing is the controlled harvest of vegetation with grazing animals, managed with the intent to achieve a specific objective. Prescribed grazing can be used to accomplish a variety of land management objectives such as control of noxious weeds and invasive plant species, reducing the incidence of wildfires, rangeland improvement, riparian and watershed management, improving wildlife habitat, and reducing nutrient competition in tree plantations. While sheep have been used for centuries to control unwanted vegetation, grazing as a fee-based service is a relatively new opportunity that is expected to expand as society looks for more environmentally-friendly ways to manage landscapes.