Breeds
Merino
The Merino sheep and its crossbreeds are the basis of southern hemisphere fine wool production. The Merino originated in Spain. The breed grows well in arid conditions as found in Australia, South Africa and parts of New Zealand.
The Merino of Australia is the backbone of the largest wool producing country in the world and this breed is the only one grown purely for its wool. The Merino ranges in micron from superfine, 12-13microns to coarse, 25-26microns, the finest grown in Australia. The bulk of Merino wool production is 20-23microns. Staple length varies from 30-90mm. This breed is found in many countries of the world and the quality of fleece produced varies greatly, depending on growing conditions and animal husbandry.
Norwegian
There is more than one breed of sheep in Norway. The oldest is a lustre wool breed known as Gammel Norsk Spelsau (translated as Old Norwegian Spelsau). The Spelsau is a breed with coarse outer hair and shorter, finer second growth. It is related to the Gotland and also the breeds of sheep found in Iceland and Faeroe.
However, the main breed in Norway is now a crossbred sheep, produced by crossing the Cheviot, which was imported from the UK in the 1800’s, and the Dala and Steigar breeds, native to Norway. The wool produced from the first clip is shorn in summer. It is approx. 29-36microns and 80-120mm long, which makes it suitable for combing. This wool is suitable for felting, hand knitting yarns and woven garments, where good resilience is required.
Shetland
The Shetland is the smallest of the British breeds found mainly on the Shetland Islands. It is believed to be of Scandinavian origin. The breed produces wool in several shades, including white, brown (moorit), grey and black. The wool is fine, soft and silky to the touch with a good, bulky down characteristic.
Production is fairly small and much of the clip is consumed by the islanders themselves. The wool varies in quality from approximately 28-33microns and fibre length from 50-120mm. The name ‘Shetland’ has become generic. Much of the knitwear available in the general marketplace is not produced from Shetland wool at all, but from wools of other origins, which have a similar quality and appearance.
The origin of the Jacob or Spanish sheep is not known with any certainty. The first flocks in the UK were based on stock imported from the former Cape Colony, having been established there by settlers from Spain & Portugal. The fleece is mottled/patchy in appearance with the dark patches becoming lighter as the sheep matures. This breed is in demand for handmade textiles as the range of colours produced are more varied than other breeds. The quality of the fibre ranges from approx. 32-40microns and length, 80- 150mm.
Blue-Faced Leicester
Blue-faced Leicester wool is classed as long-wool with lustre. The breed evolved during the 19th Century and originally came from the Tyne and Wear valleys, and hills of east Cumbria. It was sometimes referred to as ‘Hexham Leicester’.
The wool is fine and dense with a good lustre and is long. Therefore, it is well suited to combing. The sheep produces a fairly small weight of fleece for its size and the fleece has been highly prized in recent years for its likeness to mohair, for production of attractive lustrous yarns with good resilience. The fleece is available in white and natural brown hue.
Masham
The Masham, pronounced massam, is a cross of Teeswater or Wensleydale ram with Dalesbred or Swaledale ewes. The fleece is very long and lustrous and the breed is found mainly in the north of England. The fleece is suited to combing due to its length and is used in speciality products due to its limited availability. The fineness varies from approx. 38- 44microns and length approx. 150-380mm.
Suffolk
This UK breed is classified as short-wool and down. It is the most widely distributed breed of all the British breeds. Its dense fleece is suited to knitwear and any other application where a good bulk is required. It is a cross-breed of Norfolk and Southdown and has become a breed in its own right. The wool of the Norfolk was used in the original East Anglian cloths, which were made in the medieval times, which is where many of the cloths were produced at that time.
Black Welsh
This is the only purely black breed of sheep to be found in the UK. Its fleece is fine enough to be used in speciality products and is long enough to be combed. The breed is classified as mountain and hill and is found throughout the whole of the UK but originated in the Welsh mountains and uplands. The fibre fineness is approx. 30-40microns and the length, 80-100mm. It is quite bulky but carries more dead hairs (kemps) than other breeds. There is sufficient quantity of this wool to be used commercially.
Gotland
The Gotland is a native breed of Sweden. It is one of the oldest sheep breeds. The breed has been exported and small flocks can be found in other countries, including Norway, Denmark, the UK and USA. It is native to the province of Gotland and is a sheep from open pasture.
The breed is now predominantly medium grey colour and is commonly known as the Swedish Pelt Sheep. Lambs-wool of this breed is in demand for its softness and lustre, being long enough to be combed. The older sheep-wool is a little too coarse for use in garments and not so lustrous. The fleece is also quite curly and similar in some ways to mohair. The fibre fineness ranges from 30- 44microns with the lambs-wool at the finer end. The length is approx. 80-150mm.
Wensleydale
This UK breed is classified as a long-wool and lustre. Found mainly in the north of England. It is a hornless sheep with a blue face. It has a fairly curly and very long fleece. It is often used for blending with finer but shorter stapled wools, where a strong yarn is required. The wool is approx. 40-50microns and 200- 300mm long.
Teeswater
This UK breed is classified as long-wool and lustre and is found in Northern England. When crossed with other hill breeds, such as the Swaledale, it produces a halfbred sheep called Teeswater half-bred, more commonly known as the Masham. The sheep produces a long curly and lustrous fleece, a characteristic which is passed onto the Masham. The wool is approx. 40-60microns with a staple length approx. 150-300mm.
Corriedale
This is a New Zealand sheep breed, produced by crossing merino sheep with Lincoln and Leicester to produce a sheep with sound, long staple in the crossbreed range. The breed is now farmed internationally, including Australia and the USA. The fleece is a bright white with good crimp and soft handle and is very even. The wool produced is approx. 25-30microns and staple length, 80-120mm.
Cheviot
This UK breed is classified as mountain and hill. It is found in the uplands of the Scottish borders, Northumberland, South Wales, Canada, Scandinavia, USA, South Africa and New Zealand. The fleece varies in quality from fine to coarse and has many applications, making this wool very versatile. It is of a good, white colour overall. It is not too crimpy and is quite resilient, which makes the wool suitable for filling purposes, where a good white background is required.
The wool found its popularity in the Cheviot suitings/fabrics, typical of Scottish border town production and has found its way into blankets, rugs and hosiery articles. The fineness is approx. 30-40microns and length, 80-100mm.
Falkland
The term, Falkland wool, refers to wool grown only on the Falkland Islands and not in any other location. The wool clip from these islands is a very good white and is grown from Merino and Polwarth breeds. The majority of the wool produced emanates from the Polwarth. The clip is relatively small compared to other world clips and was, until recently sold predominantly through the UK.
Fineness ranges from 18/19microns to 32/33microns with the bulk of the wool being in the 27- 30microns category. The length is 80-100mm with the fleece showing good bulkiness and soft handle. In some ways, and for certain applications, it can be considered better than Australian grown wool, especially for knitting yarn, where good bulk is required.
Swaledale
This UK breed is classified as mountain and hill and is found predominantly in the northern counties of England and the Pennine hills. The fleece varies in colour from white to grey, being a similar breed in appearance to the Blackface sheep. So, the overall appearance is light grey. The wool is predominantly used in carpet yarns and rug yarns due to its excellent resilience and hardwearing properties. Some wool finds its use in hand-knitting yarns. The fineness is approx. 40-60microns and length, 100-200mm
Devon
Devon is predominantly classified as long-wool and lustre. However, there is also a production of Devon close-wool, which is finer and shorter and does not have the same lustre. The wool fleece is one of the heaviest clips in the UK with fleeces weighing up to 10kgs. It is good felting wool and with the added lustre and resilience is ideally suited for carpet manufacture. The lambs from this breed are excellent for knitwear and woven fabrics. The fineness is approx. 40-60microns and length, 200-250mm.
Texel
This is a Dutch breed, which is also found in other countries, including the UK. It is an ideal sheep for crossbreeding. The sheep produces a good dense fleece of medium quality, which is suitable for fine carpet yarns, hosiery and knitwear, at the coarser count end. The wool is predominantly white, with fineness approx. 32-40microns and length, 80- 150mm. https://www.worldofwool.co.uk/apps/base/blog/sheep-breeds-and-their-characteristics
Alphabetic Breed Listings
A-B C D E-G H-J K-L M-N O-P R S T-V W-Z
Feeding Management
Nutrition plays a major role in the overall productivity, health, and well-being of the sheep flock. Because feed costs account for approximately two-thirds of the total cost of production on most Virginia sheep farms, it is important that producers consider nutrition management a top priority. Nutrient requirements of sheep vary with differences in age, body weight, and stage of production. The five major categories of nutrients required by sheep are: 1) water; 2) energy; 3) protein; 4) vitamins; and 5) minerals. During the grazing season, sheep are able to meet their nutrient requirements from pasture and a salt and mineral supplement. Hay is provided to the flock when forages are limited, and grain may be added to the diet at certain stages of production when additional nutrient supplementation is required. Small grain pastures or stockpiled fescue can supply up to one-half of the feed requirements of the ewe flock during the winter. For winter-born lambs, creep diets and diets for early-weaned lambs are formulated from high energy feed grains and protein supplements to promote accelerated growth. During the grazing season, pastures of mixed grass and clover, alfalfa, small grain, and turnip serve as excellent sources of nutrition for growing lambs. A source of clean, fresh water is provided to sheep at all times.
Feeding the Ewe Flock
Ewe body weight does not remain constant throughout the year, but changes with stage of production. Nutrient requirements are lowest for ewes during maintenance, increase gradually from early to late gestation, and are highest during lactation. Decisions affecting feeding management are improved significantly by knowing ewe body weight and condition score at three distinct stages of production: 1) three weeks before breeding; 2) mid-gestation; and 3) weaning. Condition score is a subjective measure of body fat that is most easily determined by handling ewes down their back. It is the best method available to monitor nutritional status and overall well-being of the sheep flock. Condition scores range from 0 to 5, with 0 being extremely thin and 5 being very fat. Condition scores at either end of the scale are undesirable. Ideally, ewes should range from a condition score of 2.5 at weaning to a 3.5 at lambing. When necessary, thin ewes are separated and fed additional energy to increase body condition. Conversely, obese ewes are separated and fed a lower energy diet at a stage of production when body weight loss is acceptable. It should be noted that problems with overfat ewes are far fewer than those associated with ewes that are too thin.
Starting two weeks before breeding and continuing two weeks into the breeding period, ewes should be placed on high-quality pasture or supplemented daily with .75 to 1 pound whole shelled corn or barley. This management practice is called flushing and has been shown to improve lambing percentage by 10 to 20 percent. Flushing works best with mature ewes that are in moderate body condition, and has been shown to be more effective for early- and out-of-season breeding than at the seasonal peak of ovulation during the fall. Most prenatal deaths occur within the first 25 days after breeding and are usually associated with poor nutrition. Therefore, it is important not to make dramatic reductions in nutrient supplies during the breeding season. Pastures with more than 50 percent clover or other legumes should be avoided during breeding because legumes may contain estrogenic compounds that reduce conception rates. From breeding to six weeks before lambing, the ewe flock can be maintained on permanent pastures, small grain pastures, stockpiled fescue, aftermath crop fields, or hay. Fetal growth is minimal, and the total feed requirement of the ewe is not significantly different from a maintenance diet.
The developing fetus acquires approximately two-thirds of its weight during the last six weeks of pregnancy. Rumen capacity may be limited with ewes carrying multiple foetuses. Therefore, it is important to supplement ewes with .75 to 1 pound of corn or barley in addition to their normal diet starting six weeks before lambing, to prevent pregnancy toxemia, low birth weights, weak lambs at birth, and low milk production. Producers should be careful not to overfeed grain during late gestation, which could result in lambing difficulty caused by large lambs.
After lambing, the energy and protein requirements of the ewe increase by 30 and 55 percent, respectively. Failure to supplement ewes accordingly results in excessive body weight loss, low milk production, mismoothering, and poor lamb gains. Protein supplementation is especially critical for ewe flocks with a high percentage of multiple births. Unless high quality legume hays are fed, protein supplementation will be necessary as a part of the grain portion of the diet. A general rule of thumb for concentrate feeding of lactating ewes is 1 pound of grain for each lamb nursing the ewe. Ewes should be sorted into feeding groups based on type of rearing (single, twin, etc.) to make sure grain supplements are neither over- or underfed. Table 1 gives the TDN and crude protein requirements of ewes based on body weight and stage of production. By knowing the nutrient requirements of the ewe and the nutrient content of the feed, diets can be properly formulated to meet the nutritional needs of the ewe. Shown in Table 2 are the estimated quantities of hay, corn and soybean meal that would be fed to a 175 pound ewe at different stages of production and with different crude protein values for the hay. To successfully use this table, hay samples should be submitted to a testing lab to determine its crude protein content.
| Table 1. Changes in the Daily Total Digestible Nutrients (TDN) and Protein Requirements of a Ewe from Maintenance Through Early Lactation. | ||||||||
| Stage of production | Ewe weight | |||||||
| 130 lba | 155 lba | 175 lba | 200 lba | |||||
| TDN | Protein | TDN | Protein | TDN | Protein | TDN | Protein | |
| lb | ||||||||
| Maintenance | 1.30 | 0.23 | 1.50 | 0.25 | 1.60 | 0.27 | 1.70 | 0.29 |
| Early pregnancy | 1.60 | 0.27 | 1.70 | 0.29 | 1.80 | 0.31 | 1.90 | 0.33 |
| Late pregnancyb | 2.60 | 0.45 | 2.80 | 0.47 | 2.90 | 0.49 | 3.00 | 0.51 |
| Early lactation, single |
3.30 | 0.70 | 3.60 | 0.73 | 3.70 | 0.76 | 3.80 | 0.78 |
| Early lactation, twins |
3.70 | 0.89 | 4.00 | 0.92 | 4.30 | 0.96 | 4.60 | 0.99 |
| Early lactation, tripletsc |
3.90 | 0.99 | 4.20 | 1.02 | 4.60 | 1.06 | 5.00 | 1.10 |
| aBased on ewe weight at breeding time. bNational Research Council recommendations for ewes expected to have a 180-to 225-percent lamb crop. If 130-to 150-percent lamb crop is expected, then you can reduce total digestible nutrients by 0.4 pound and protein by 0.05 pound. cEstimates made by adding on one-half of the difference between ewes nursing singles and twins to the amount indicated for ewes nursing twins. |
||||||||
| Table 2. The Amount of Hay, Shelled Corn (SC), and Soybean Meal (SBM) Required to Meet the Total Digestible Nutrients (TDN) and Crude Protein (CP) Requirements of a 175-lb Ewe When the Hay Contains Different Protein Levels. | |||||
| Stage of production | Percent protein in hay* | ||||
| 16.5 | 15.0 | 12.5 | 10.0 | ||
| lb | |||||
| Maintenance | Hay | 3.25 | 3.25 | 3.25 | 3.25 |
| Early pregnancy | Hay | 3.75 | 3.75 | 3.75 | 3.75 |
| Late pregnancy | Hay | 4.20 | 4.20 | 4.20 | 4.20 |
| SC | 1.00 | 1.00 | 1.00 | 1.00 | |
| SBM | — | — | — | 0.10 | |
| Early lactation (single) | Hay | 5.00 | 5.00 | 5.00 | 5.00 |
| SC | 1.50 | 1.50 | 1.40 | 1.15 | |
| SBM | — | — | 0.10 | 0.40 | |
| Early lactation (twins) | Hay | 5.00 | 5.00 | 5.00 | 5.00 |
| SC | 2.25 | 2.10 | 1.90 | 1.15 | |
| SBM | — | 0.10 | 0.40 | 0.75 | |
| Early lactation (triplets) | Hay | 3.50 | 3.50 | 3.50 | 3.50 |
| SC | 3.15 | 2.95 | 2.70 | 2.45 | |
| SBM | 0.45 | 0.65 | 0.90 | 1.15 | |
| Note: Adjusted from dry matter values: Corn – 80 percent TDN and 8.8 percent CP, SBM -80 percent TDN and 44 percent CP, Hay – 50 percent TDN. TDN of hay increases as hay quality increases, but is left constant here for ease of discussion and diet calculations. *Percentages are figured on an as-fed basis, as are the pounds of feed. |
|||||
Feeding Lambs
Feeding programs in Virginia for growing and finishing lambs are different for winter- and spring-lambing production systems. Lambs born from November through early February will likely be grown and finished on high concentrate feeds. Lambs born after the middle of February are placed on pasture with their dams where they remain throughout the spring and summer. If necessary, spring-born lambs are weaned and finished to market weight in the fall, using a grain on grass feeding program or placed in a feedlot for an abbreviated period of high concentrate feeding.
Lambs on a winter-lambing program should have access to a high quality creep feed by the time they are seven days old. Creep feeds should contain 18 to 20 percent crude protein and be low in fiber (high in energy). The source of protein in commercially prepared lamb creep pellets should be all natural protein. Because the rumen of young lambs is not fully developed, urea should not be used as a partial source of protein in the diet. A 2:1 calcium to phosphorous ratio is maintained in on-farm feed mixes by adding feed grade limestone at 1 percent of the diet. Calcium to phosphorous ratios of less than 2:1 may lead to urinary calculi (water belly), which most often results in the death of the lamb. If the addition of limestone to the diet fails to control urinary calculi, ammonium chloride should be added at .5 percent of the diet. When constructing a creep area, keep the following points in mind: 1) place the creep in a convenient location close to an area where the ewe flock congregates; 2) have openings on at least two sides of the creep and several openings per side; 3) keep the creep area clean and well bedded; 4) place a light over the creep to help attract the lambs to the feed or arrange the creep in such a way that the sun shines into the area during the day; 5) provide fresh water in the creep area; and 6) construct the creep feeder so that lambs cannot stand and play in it. Allow 2 inches of trough space per lamb.
Winter-born lambs should be weaned and adjusted to a growing diet by the time they are two months of age. A growing diet for lambs weighing 40 to 70 pounds should contain approximately 78 percent TDN and 16 percent crude protein. At body weights of 70 pounds and up, the level of crude protein in the diet can be lowered to 14 percent. Feed efficiency values range from 2 pounds of feed per pound of gain for light weight young, growing lambs on up to 3.5 to 4 pounds of feed per pound of gain as winter-born lambs approach their optimum market weight. Feed efficiency values for old-crop (spring born) feeder lambs weighing 75 pounds and up in the fall average 5 to 5.5 pounds of feed per pound of gain when a whole-grain feeding program is used. Whole-grain feeding improves feed efficiency, increases rate of gain, and lowers the feed cost per pound of lamb gain. Whole-grain diets consist of whole (unprocessed) grains, such as shelled corn or barley, mixed with a pelleted protein-mineral supplement. No roughage is contained in the feed or supplemented on the side. Consequently, the diet is high in energy and promotes accelerated lamb gains.
Ground ear corn, silage, and urea should not be fed until lambs are weighing 65 pounds and up. Creep diets should be ground or pelleted. Weaned lamb growing and finishing diets may be ground, pelleted, or consist of a mixture of whole grain and a pelleted supplement.
Ram Feeding
Rams should have a body condition score of 3.5 to 4 before the beginning of the breeding season. Once turned in with the ewes for breeding, rams spend very little time eating. They can lose up to 12 percent of their body weight during a 45-day breeding period. That equates to 30 pounds for a 250 pound ram. Poor nutrition is a major cause of ram mortality. As the sheep industry has moved away from smaller framed, earlier maturing types of sheep to larger framed, later maturing types of sheep, they have increased the rams’ mature body weight. In many cases, forage alone is not adequate nutrition for placing rams in proper body condition for the breeding season. At the very least, rams should be evaluated for body condition six weeks before breeding. Thin rams should receive grain supplementation as a means to increase body weight and condition. It takes 50 days and approximately 2.5 pounds of corn per day in addition to a ram’s normal diet to move him from a weight of 225 pounds to 250 pounds. Mature rams, not in breeding, can be maintained on pasture or wintered on good quality hay. Six to eight pounds of mixed grass and clover hay is sufficient to meet the daily energy requirements of a 250 pound ram. A free choice source of water, salt, and minerals should be available at all times.
Feeds for Sheep
Pasture
Permanent pasture should be the predominant source of nutrition for the sheep flock. Intensive sheep production systems where the sheep are housed and fed harvested feeds are not as profitable as more extensive production systems where they harvest their own feed. When a sufficient quantity of forage is available, sheep are able to meet their nutrient requirements from forage alone along with a supplemental source of salt and minerals. Clover should be overseeded on permanent pastures in the winter to improve the quantity and quality of forage produced during the grazing season. Sheep prefer to graze leafy, vegetative growth that is 2 to 6 inches tall rather than stemmy, more mature forages. Pasture growth is not distributed evenly throughout the year. Approximately 60 percent of the annual dry matter production of most species of cool season grasses occurs in the spring. When pastures are not stocked heavily enough to utilize the spring flush of growth, sheep graze and regraze certain areas while other areas are left to mature and go to seed. This type of grazing behavior weakens those plants that are grazed more frequently and gives the less desirable plants a competitive advantage. Approximately one-third of spring pasture should be fenced for hay production. After a hay cutting, pasture should be given a three- to four-week recovery period before making it available for grazing the remainder of the year. Rotational grazing programs designed for the movement of sheep every 10 to 14 days are instituted in late June and early July to improve both pasture and lamb production. More intensive rotational grazing systems where higher stocking rates are used help to promote more complete forage utilization, but also require greater input costs in the form of fence and water and may result in higher levels of internal parasitism, increased risk of coccidiosis, and impaired lamb performance.
Hay
Average or poor quality hay should be fed during gestation, leaving the higher quality hay to be fed during lactation. Because protein requirements of the ewe increase dramatically after lambing, less protein supplementation from concentrate feeds is required when higher quality hay is used. Second-cutting, mixed grass-clover hay may be more economical to feed to the ewe flock than alfalfa hay. This is especially true if alfalfa hay must be purchased from off the farm. Alfalfa hay is an excellent feed for sheep and is best used during lactation when ewes require more protein to promote higher levels of milk production. Many producers have fed alfalfa hay to gestating ewes with good results. However, some producers feeding alfalfa hay to gestating ewes have experienced problems with vaginal prolapses, late term abortions, and milk fever. If alfalfa hay is being fed during late gestation, it should be limit fed and be free of must and mold. Because of its high quality and palatability, ewes consume more alfalfa hay than is needed. The bulkiness of the hay in the rumen may place pressure on the reproductive tract, resulting in a vaginal prolapse before lambing. Ewes receiving alfalfa hay during gestation are more prone to milk fever than ewes fed grass hay. Because alfalfa is high in calcium, ewes are able to meet their calcium requirements without mobilizing body stores of calcium. However, after lambing, ewes not accustomed to mobilizing bone calcium may experience milk fever because of their inability to meet the additional calcium requirements associated with lactation. Regardless of the type of hay fed, producers should submit hay samples to a forage testing lab to determine its nutrient content. By knowing the nutrient content of the hay, diets can be more accurately and economically formulated for the sheep flock.
In general, there is less waste and more flexibility when feeding hay harvested as square bales. However, round bales can provide quality feed for sheep when stored and fed properly. To minimize dry matter and nutrient losses, which can approach 40 to 50 percent, round bales should be covered with plastic for outside storage or placed under shelter. Bales should be stored on pallets or tires to prevent ground contact. Feeding round bales without a feeder may result in as much as 30 percent of the hay being wasted, and poses a hazard to the sheep should the bales roll over. A variety of round bale feeders are commercially available. Feeders designed in the shape of a cradle hold the bales up off the ground, are maintenance free, and appear to work best for minimizing waste.
Silage
High quality, finely chopped (1/4 to 1/2 inch) corn, grass, or small grain silage is acceptable feed for sheep. Care must be taken to properly harvest, store, and feed silage. Poorly packed silage may contain harmful molds, which causes listeriosis (circling disease) in sheep. Moldy or frozen silage should be discarded and troughs should be cleaned daily.
Corn silage is low in protein and calcium. Studies have shown that the addition of 20 pounds of urea, 10 pounds of ground limestone, 4 pounds of dicalcium phosphate, and 5 pounds of calcium sulfate per ton of silage at the time of ensiling makes a complete feed for the ewe flock by increasing its crude protein and calcium content. Alternatively, extra protein, calcium, phosphorous, and vitamins can be supplied through a grain mix topdressed on the silage at the time of feeding.
Because of its high moisture content, 3 pounds of silage is required to supply the TDN furnished by 1.5 pounds of hay. The bulkiness of silage prevents adequate dry matter intake and its use as the sole source of feed for ewes in late gestation. A typical diet fed to ewes during the last four weeks of pregnancy on an as fed basis would contain: 6 pounds of corn silage (35 percent dry matter), 2 pounds of hay, 0.5 pound of corn, and 0.25 pound of soybean meal.
Grain
When additional energy and protein are required, corn and soybean meal commonly form the basis of the grain portion of the diet. However, when justified by supply or price, other grains may replace all or part of the corn and soybean meal in a diet. The energy value of other common grains compared to corn and the maximum amounts to use in ewe and lamb diets are given in Table 3. Because of its high fiber content, the replacement value of oats ranges from 50 to 100 percent. The higher replacement rate is used for breeding sheep, while the lower rate is used in creep feeds and finishing diets for lambs. Alternative sources of protein to soybean meal include cottonseed and peanut meal.
| Table 3. Value of Grain Substitutes for Corn. | ||
| Ingredient | Energy Value of Corn % | Maximum Replacement for Corn (%) |
| Corn | 100 | 100 |
| Barley | 90 | 100 |
| Oats | 80 | 50-100 |
| Wheat | 100 | 50 |
| Sorghum | 90 | 100 |
Differences in Value
To determine if other feeds are a better value than corn or soybean meal, comparisons can be made based on the cost per unit of nutrient. If corn is selling for $0.06 per pound and barley is selling for $0.05 per pound, which is the better buy for TDN? Divide $0.06 per pound by 92 percent TDN for corn to get $0.065 per pound of TDN. Divide $0.05 per pound by 85 percent TDN for barley to get $0.059 per pound of TDN. In this example, even though barley has a lower TDN value than corn, it is still a better buy than corn. If alfalfa hay is selling for $120 a ton and soybean meal is selling for $250 a ton, which is the better buy for crude protein? Divide $0.06 per pound by 15 percent crude protein for alfalfa hay to get $0.40 per pound of crude protein. Divide $0.125 per pound by 44 percent crude protein for soybean meal to get $0.284 per pound of crude protein. In this example, even though alfalfa hay is selling for less than half the price of soybean meal, soybean meal is still a better buy than alfalfa hay.
Alternative Feeds
Table 4 provides a list of some of the by-products of grain milling and processing and certain non-traditional feeds that are commonly available in Virginia. They are considered to have more value and less risk when fed to the ewe flock than to lambs. Caution should be used when substituting alternative feeds for corn and soybean meal when they appear to be a better value. Although these feeds may be comparable in terms of nutrient analysis, the animals may not perform similarly. Therefore, it is important to know if there are problems with certain alternative feeds, and to monitor the performance of the sheep flock once changes have been made.
| Table 4. Potential Alternative Feeds for Sheep in Virginia. | |||
| Ingredienta | Average Nutrient Value | Limitations | Remarks |
| Corn Gluten Feed | 80% TDN 24% Crude Protein | No Limitations | Best used as a source of protein to go with corn or barley |
| Dry Distillers Grains | 87% TDN 27% Crude Protein | No Limitations | Can be substituted for up to one half of the soybean meal in the diet without losing the benefits of all soybean meal |
| Hominy Feed | 92% TDN 11% Crude Protein | Limit to 1 lb per day | Feed within one month of purchase |
| Soybean Hulls | 77% TDN 14% Crude Protein | No Limitations | Works well as a supplement to hay |
| Wheat Midds 18% Crude Protein | 82% TDN | Limit to 1 lb per day | Pelleted form is easier to handle and feed |
| Whole Cottonseed 23% Crude Protein | 94% TDN | Limit to l lb per day | Contains Gossypol and should not be fed to young lambs |
| aWith the exception of soy hulls, all of these feeds are low in calcium and high in phosphorous. Therefore, calcium supplementation is necessary when these feeds are used. | |||
Urea
Urea is not a protein supplement, but a source of nonprotein nitrogen (NPN) for protein synthesis by rumen bacteria. It 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. To determine the pounds of nitrogen in a diet, multiply the total pounds of crude protein in the diet by 16 percent. Other general rules for the use of urea are: 1) should not be more than 1 percent of the diet or 3 percent of the concentrate mix; and 2) should not be more than 5 percent of a supplement to be used with low grade roughages.
Minerals
Salt and mineral supplementation is required on a free choice, year-round basis. Failure to supplement salt and minerals results in low fertility, weak lambs at birth, lowered milk production, impaired immunity, and numerous metabolic disorders. A variety of salt and mineral supplements specifically formulated for sheep are commercially available. These supplements range from trace mineralized salt (TMS) fortified with selenium 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 grazing low quality roughages, starting four weeks before breeding, during breeding, and during late gestation and early lactation. Virginia is a selenium deficient state. Studies have clearly shown that selenium supplementation for pregnant ewes via a mineral mix is superior to selenium injections in late gestation. Mineral supplements formulated for cattle and horses should not be used for sheep because they are high in copper, which is toxic to sheep. Mineral concentration is oftentimes expressed in parts per million (ppm). Equivalent expressions for 1 ppm are 1 milligram per kilogram or .0001 percent. When high grain diets, certain alternative feeds, or silage are fed to sheep, additional calcium is required in the diet. This can be supplied by adding feed grade limestone to the feed. A general rule is to add limestone at 1 percent of the diet.
Vitamins
Pasture or high-quality hay provides the vitamins required by most classes of sheep. However, after a drought, or when low-quality hay or silage is fed, a supplement supplying vitamins A, D, and E may be needed. Estimated daily vitamin requirements for ewes during late pregnancy and lactation are: 6,500 international units (IU) Vitamin A, 400 IU Vitamin D, and 40 IU Vitamin E. To assure an adequate supply of vitamins, a vitamin supplement containing 3,000,000 IU Vitamin A, 200,000 IU Vitamin D, and 25,000 IU Vitamin E may be added to each ton of feed for ewes and lambs.
Feed Additives
Antibiotics or ionophores are often added to the diet to improve animal performance. Antibiotics are fed to reduce the incidence of subclinical bacterial infections of the digestive and respiratory tracts. Ionophores are used to control coccidiosis in lambs fed under confinement. The use of antibiotics and ionophores has been shown to improve lamb average daily gain and feed efficiency. To date, the combined use of antibiotics and ionophores in the same feed is not approved. Chlortetracycline (Aureomycin), an antibiotic, is added at the rate of 20 to 30 grams per ton of feed for lambs to improve lamb performance. Supplementing pregnant ewes with 65 mg of Chlortetracycline daily starting six weeks before lambing and continuing six weeks into lactation has been shown to cause a significant reduction in baby lamb mortality. Lasalocid (Bovatec), an ionophore, is added at the rate of 30 grams per ton of feed for lambs fed in confinement. The use of lasalocid has been shown to improve lamb gain and feed efficiency by approximately 10 percent.
Water
Sheep must have a free-choice supply of clean, fresh water. If adequate fresh water is available and convenient, a lactating ewe will consume approximately 2 to 3 gallons a day. Frozen water supplies, muddy conditions where sheep have to drink, and long distances to water reduce water intake and have a negative impact on production. Heated water bowls should be used during the winter to encourage adequate consumption of water by lactating ewes and lambs. Water bowls should be checked and cleaned on a daily basis.
Pearson Square
Protein is often the major limiting nutrient in a sheep diet. The Pearson Square is used to formulate simple diets on the basis of protein.
Problem: Using Table 1, assume a 155 lb ewe needs .92 lb crude protein per day to meet her nutrient requirements in early lactation. Four pounds of mixed grass-clover hay (13% crude protein) will be fed per day along with 2 lb of a mixture of barley and soybean meal. What proportion of barley and soybean meal should be used in the mix?
Determine the percentage of crude protein (CP) contributed by the hay.
4 lb x .88% Dry Matter = 3.52 lb Dry Matter
3.52 lb Dry Matter x 13% CP = .46 lb CP
Determine the amount of additional CP needed from the barley and soybean meal mix.
.92 lb CP Required – .46 lb CP from the Hay = .46 lb additional CP needed
Determine the percentage of crude protein needed in the barley and soybean meal mix.
2 lb x .90% Dry Matter = 1.8 lb Dry Matter
.46 lb additional CP needed ÷ 1.8 lb Dry Matter = 25.5% CP in the grain mix
Use a Pearson Square to determine the proportion of barley and soybean meal in the mix.
Subtract diagonally across the square, the smaller number from the larger number without regard to the sign and record the difference at the right corners.
The parts of each feed can be expressed as a percentage of the total.
18.5 ÷ 33.0 (100) = 56% Barley
14.5 ÷ 33.0 (100) = 44% Soybean Meal
Check the math to make sure that .46 lb CP is coming from the barley and soybean meal mix.
1.8 lb Dry Matter from Grain Mix x 56% Barley x 11% CP = .11 lb CP
1.8 lb Dry Matter from Grain Mix x 44% Soybean Meal x 44% CP = .35 lb CP
.11 lb CP from Barley + .35 lb CP from Soybean Meal = .46 lb CP from the 2 lb Grain Mix
| Table 5. Sample Diets for Creep Feeding, Growing Lambs, and Finishing Lambs. | |||||
| Feed Ingredient | 18% Crude Protein* (Percent Ingredient in the Diet) | ||||
| Cracked Corn | 54 | 59 | 54 | 68 | |
| Whole Oats | 20 | 10 | – | – | |
| Whole Barley | – | – | 20 | – | |
| Soybean Meal | 25 | 25 | 25 | 26 | |
| Feed Grade Limestone | 1 | 1 | 1 | 1 | |
| Molasses | – | 5 | – | 5 | |
| Vitamin Premix | + | + | + | + | |
| Antibiotic or Ionophore | + | + | + | + | |
| *To be fed with free choice source of high quality alfalfa hay. | |||||
| Feed Ingredient | 16% Crude Protein (Percent Ingredient in the Diet) | ||||
| Cracked Corn | 59 | 59 | |||
| Alfalfa Pellets (17% CP) | 25 | – | |||
| Ground Legume Hay (15% CP) | – | 23 | |||
| Soybean Meal | 15 | 17 | |||
| Feed Grade Limestone | 1 | 1 | |||
| Vitamin Premix | + | + | |||
| Antibiotic or Ionophore | + | + | |||
| Feed Ingredient | 13% Crude Protein (Percent Ingredient in the Diet) | ||||
| Shelled Corn | – | – | 85 | ||
| Cracked Corn | 64 | – | – | ||
| Corn and Cob Meal | – | 59 | – | ||
| Ground Legume Hay (15% CP) | 28 | 26 | – | ||
| Soybean Meal | 7 | 9 | – | ||
| Pelleted Supplement (36% CP)* | – | – | 15 | ||
| Feed Grade Limestone | 1 | 1 | – | ||
| Vitamin Premix | + | + | + | ||
| Antibiotic or Ionophore | + | + | + | ||
| *Vitamins and minerals are included in the pelleted protein supplement. | |||||
| Table 6. Feeder Space Requirements – Inches Per Head. | ||||
| Hay Rack | Grain Trough | Creep Feeder | ||
| Ewes – Limit Fed | 18-24 | 16-20 | – | |
| Ewes – Self Fed | 6-8 | 4-6 | – | |
| Baby Lambs | – | – | 2 | |
| Feeder Lambs – Limit Fed | – | 9-12 | – | |
| Feeder Lambs – Self Fed | – | 1-2 | ||
http://pubs.ext.vt.edu/410/410-853/410-853.html
Housing
Housing needs for sheep vary by climate, season(s) of lambing, and management preferences of the shepherd. If lambing will occur during periods of inclement weather, more elaborate housing is usually required. If lambing will occur on pasture during periods of mild weather, simple shelters may be all that is needed.
Lambing percentages are usually higher when shed lambing is practiced. Housed sheep have lower nutritional requirements, whereas sheep kept outside have fewer respiratory problems.
In addition, most operations need facilities where they can store feed, bedding, and equipment. Hay stored in a barn or shed will maintain its quality better than hay that is stored outside, even if the hay is covered. Equipment will last longer if it is housed under a roof.
Barns (and similar structures) are often built for the comfort and convenience of the shepherd. During cold or inclement weather, it is easier and more enjoyable to care for sheep that are housed. However, housing costs can add significantly to the investment costs of a sheep enterprise.
Options
There are many different types of housing that can be used for sheep. Traditional barns, pole buildings, and metal buildings are usually the most expensive, but they provide the best protection for the shepherd, sheep, feed, and equipment.
A lower-cost alternative to traditional housing is a greenhouse-type structure called a “hoop house.” A hoop house has an arched metal frame that is covered with a heavy fabric. Fabrics last for approximately 15 years.
Sheep facilities do not need to be built new. Old dairy, swine, and poultry barns can be converted to housing for sheep. Many facilities can be remodeled to accommodate sheep raising. Many universities and provincial governments have building plans for sheep facilities.
Site location
Facilities should be located on elevated, well-drained sites. When designing a three-sided shelter, the open side should face south away from the prevailing wind. The barn should be easily accessible for deliveries and manure handling. The site should allow for installation of water and electricity.
Space requirements
When confined to a building, a bred ewe requires 12 to 16 square feet of living space. Lambing pens should be 16 to 25 square feet in size. In group housing, a ewe with her lambs needs 16 to 20 square feet. Feeder lambs need 8 to 10 square feet.
Less space is required if sheep are raised on slatted floors or if they have access to an exercise area or pasture. Shearing before housing will allow stocking rates in the barn to be increased by up to 20%.
Recommended housing space (square feet) for sheep and lambs
| . | Dirt lot | Open shed | Confinement (dirt floor) |
Confinement (slatted floors) |
| Bred ewe | 20 | 8 | 12-16 | 8-10 |
| Ewe with lambs | 25 | 12 | 16-20 | 10-12 |
| Ram | 20 | 8 | 20-30 | 14-20 |
| Feeder lamb | 15-20 | 6 | 8-10 | 4-6 |
| Source: Midwest Plan Service, Sheep Housing and Equipment Handbook, 1982 | ||||
Ventilation
Barns should not be heated or closed up. Good ventilation is an absolute must. Respiratory problems (e.g. pneumonia and bronchitis) often result from poor ventilation. If ammonia can be smelled in the barn, ventilation is likely inadequate.
Ventilation can be accomplished by either natural or mechanical means, but usually naturally-ventilated cold housing is preferable for sheep. It is better to over-ventilate than under-ventilate. The only requirement is that sheep have a dry, draft-free area for lambing.
Bedding
Bedding provides warmth, insulation, and comfort to housed animals. Various materials can be used for bedding for sheep, depending upon their cost and availability: straw, hay, dried corn stalks, corn cobs, peanut hulls, cottonseed hulls, oat hulls, sawdust, wood shavings, wood chips, pine shavings, sand, paper products, peat, hemp, and leaves. Each type of bedding has advantages and disadvantages.
Straw is the traditional bedding for livestock. It comes from the stems of small grains: oats, wheat, rye or barley. Since straw has many uses other than livestock bedding sometimes it costs more than alfalfa hay. As a result, hay is often a cheaper alternative than straw.
Sawdust is not good bedding for wooled sheep because it gets in their fleeces, but works fine for hair sheep. Wood chips or peanut shells are less absorbent than other materials, but can be used as bedding.
Shredded paper (or newsprint) is more absorbent than straw, but is more difficult to handle and may look offensive when spread on fields. Sand has been used by dairy farms to reduce mastitis and improve cow comfort. No matter what material is used for bedding, it needs to be clean and dry.
Livestock bedding alternatives
| Bedding material | Absorption factor* |
| Wheat straw | 2.1 |
| Barley straw | 2.0 |
| Oat straw | 2.4 to 2.5 |
| Hay | 3.0 |
| Sawdust | 1.5 to 2.5 |
| Shavings | 1.5 to 2.0 |
| Corn stover | 2.5 |
| Sand | 0.3 |
| Peat moss | 10.0 |
| * Weight of water held per unit of try material. Assumes initial moisture content of bedding < 10%. |
|
| Source: Livestock Bedding Alternatives, Ontario Ministry of Agriculture, 1997. | |
Keeping Sheep Outside Year-round
Some producers keep their sheep outside year-round. It is more natural. Sheep kept outside benefit from better ventilation and more exercise. Their fleeces stay cleaner. Winter grazing can result in considerable feed savings. Tall fescue is usually the best forage for stockpiled grazing.
Sheep can graze through approximately 12 inches of snow. If the snow is not hard or crusted, the sheep can usually eat enough snow to meet their water requirements; otherwise they need to be watered at least once per day. Lactating ewes should have access to water at all times.
It is common to temporarily house sheep after shearing and/or during lambing. Adult sheep can handle cold and wet weather rather well, but newborn lambs cannot. The combination of cold and wet can kill even a two week old lamb, if there is not sufficient shelter. Emergency shelter is needed for bad storms. Nutrition is the key to keeping sheep outside in the winter. If they have enough to eat, they will stay warm.
Not having to clean the barn and spread manure on the fields is another major benefit to keeping sheep outside.
Shelter and Shade
There is disagreement as to whether sheep require shelter while they are on summer pasture. Sheep will usually choose shelter if it is available to them. Protection from heat is probably more important than protection from rain, though hair sheep are more likely to seek shelter from rain than wooled sheep and less likely to seek shade during the heat of the day.
In many cases, trees or a windbreak is all the shelter that sheep need. In open fields without sufficient tree coverage, simple run-in sheds or shade structures can be constructed or purchased. Port-a-huts, calf hutches, polydomes, and carports are useful for small flocks.
Total Confinement
Sheep can adapt to a complete confinement system of production. Confinement enables a producer to raise sheep or increase flock size in situations where land is a limiting factor due to availability or cost. Confinement can vary from open, dry (dirt) lots to buildings with expanded metal floors and automated manure handling systems. Confinement requires intensive, year-round management. Because it tends to have a higher cost of production, higher levels of performance are usually required.
There are numerous advantages to raising sheep and/or lambs in total confinement. Predator problems can be eliminated by keeping sheep in confinement. Internal parasite problems can be practically eliminated, as infective worm larvae is consumed primarily by grazing animals.
It is usually easier to control foot rot and foot scald in confinement. Confinement lends itself well to automated feeding systems. It is common to fatten (feed) lambs in confinement. Less space is needed if expanded metal or mesh flooring is used. The use of rubber mats will improve comfort and insulation.
In fragile environments, confinement can prevent overgrazing or other environmental impacts caused by poor grazing management. Zero grazing is common in many third world environments.
Security is superior when animals are kept in small areas that can be more easily monitored.
http://www.sheep101.info/201/housing.html
Diseases
Abortion
Abortion occurs when a ewe’s pregnancy is terminated suddenly and the lambs she delivers are lost due to premature birth. The birth of weak or deformed lambs which are alive, but die shortly after birth can also technically be labeled as abortion. The causes of abortion can be both physical or infectious.
The three most frequently observed infectious causes of abortion in ewes in the United States are Toxoplasmosis (Toxoplasma gondii), Enzootic Abortion (Chlamydia), and Vibrio (Campylobacter). You may have heard of these organisms before as they can also cause abortion (miscarriage) in women. It’s important that pregnant women avoid handling lamb fetuses or placental fluids from aborted or miscarried lambs.
Physical trauma or stress can cause early-delivery or abortion of lambs in ewes, which is why it’s important to take care in handling pregnant ewes and to avoid loud noises or sudden movements which could spook them and result in physical injury.
Acidosis
Acidosis, also called lactic acidosis, ruminal acidosis, grain overload, or grain poisoning, is the result of excessive consumption of concentrated food (grain), which produces elevated acid levels in the sheep’s rumen. Symptoms include depression or listlessness as well as abdominal pain (though this is typically harder to observe).
Acidosis in sheep can be a life-threatening condition and action should be taken immediately to drench affected sheep with an antacid such as carmalax, baking soda, or similar products containing magnesium carbonate or magnesium hydroxide.
It’s important to know that Acidosis is generally caused by poor feeding management practices and it can be avoided by introducing grain to sheep’s diet gradually, ramping up consumption to the desired level over time. This will allow the sheep’s digestive system to acclimate properly and you’ll provide the sheep’s rumen with time to adjust to the concentrated food source.
Arthritis
Similar to humans, arthritis in sheep is an inflammation of the sheep’s joints – typically leg joints – which can cause a loss of production, conditioning, and death. In sheep the primary cause of arthritis is bacteria which can enter the sheep’s body through any break in the sheep’s skin.
Sheep are susceptible to bacteria which cause arthritis after birth (umbilical cord), during docking, castration, and ear tagging. Other moments when sheep are at risk are when they sustain wounds from shearing, nails, or other sharp objects in their environment.
Erysipelothix rhusiopathiae is the bacteria which most commonly causes arthritis in sheep, but there are several others which can also cause this sheep disease. You will typically observe swollen, hot or painful joints anywhere from 2 days to 2 weeks after infection occurs. Administering antibiotics is the proper treatment of arthritis in sheep, but this disease can be avoided if proper sanitation and hygiene practices are observed on your farm.
Bent Leg or Rickets
You may have heard of Rickets before, and in sheep, “Bent Leg” is a form of this disease which is caused by errant bone metabolism during growth. Bent Leg typically will occur during the period in which sheep experience their most rapid growth rate (between 6 and 12 months). You’ll typically observe Bent Leg in rams most of the time, but it can also occur in ewes (though it is less common). TheRambouillet sheep breed is one in which Bent Leg is most frequently observed.
Prevention of Bent Leg is a matter of observing proper feeding and management practices on your farm. Feed balanced rations and avoid pushing animals to consume high-levels of high-protein feed. Ensure that lambs are provided with a calcium to phosphorus ration of at least 1.5 to 1 in their food, and consider supplementing their diet with at least 300 IU of vitamin D per day for every 100 pounds of body weight. In addition to vitamin D supplementation, it’s considered a good practice to shear young rams in the fall, which can help with vitamin D conversion (more skin surface is exposed to the sun). You should also try to provide housing for your sheep which provides plenty of exposure to the sun during winter months when sunlight is at a premium.
Bloat
Bloat is a sheep disease caused when the rate at which gas is produced in the rumen (stomach) exceeds the rate at which gas is eliminated. This produces a condition where gas accumulates within your sheep’s abdomen, resulting in distention or swelling of the rumen.
Bloat is typically observed when the skin behind your sheep’s last rib is distended and/or swollen. This condition can be a medical emergency and intervening in a timely manner can be necessary to prevent the sheep’s death. Bloat in sheep is a common cause of sudden death and is typically caused by something in the sheep’s nutrition.
The two common causes of bloat in sheep are Pasture Bloat (Frothy Bloat) and Feed Lot Bloat (Free Gas Bloat).
Pasture Bloat earned its name due to its association with sheep consuming leguminous forages, cereal grain pastures or wet grass pastures, though it can also be caused by consuming grain which is ground too finely. Cooking oil, mineral oil or a product like Poloxalene can be administered orally as treatment.
Feed Lot Bloat is commonly the result of heavy grain feeding and often results when your sheep weren’t allowed a long enough period to acclimate and adjust to a diet of heavy grain consumption. Passing a stomach tube down the sheep’s throat and into the sheep’s stomach can help to relieve bloat, and a last-resort (life-saving measure) can be to insert a trochar needle into the abdomen of the sheep. This should only be a last-resort and you should ask a veterinarian to perform this procedure if possible.
Bluetogue
Transmitted by insects, Bluetongue is a viral disease which affects most domestic and wild ruminants, including sheep. For shepherds, a case of Bluetongue is serious as it’s possible for half of the sheep in an infected flock to die. Bluetongue earned its name due to the symptoms of the disease, which are inflamed, swollen or hemorrhaging mucous membranes of a sheep’s mouth, nose and/or tongue.
It’s important to know that soreness of the feet are also associated with Bluetongue, and this may be a symptom. More commonly, though, you should look for swollen or hemorrhagic membranes in the mouth or tongue which can present as a dull blue color. Biting gnats spread the disease from one animal to the next, and in the United States the disease is much more common in the southern or southwestern regions, where these insects are most prevalent.
Animals with the disease cannot spread it to other animals (only insects can spread it), so there’s no need to separate infected members of your flock. There is a vaccine, but it is only effective against certain strains and may cause adverse reactions, so many shepherds choose not to vaccinate. Pregnant ewes should never be vaccinated for Bluetongue.
Border Disease
Sometimes referred to as hairy shaker disease or fuzzy-lamb syndrome, Border Disease afflicts newborn lambs. Affected lambs will typically have a hairy coat and will tremble uncontrollably. This viral sheep disease will present with a range of symptoms depending upon when the ewe is affected by the virus, ranging from abortion of mummified lambs to the symptoms mentioned above which are observed in lambs after delivery.
The way most sheep contract border disease is if they are kept in close proximity to cattle or new additions are made to a flock from a farm where sheep were kept with cattle which have bovine viral diarrhea. There is no treatment for sheep affected with border disease and sheep with the disease won’t respond to antibiotics.
Caseous Lymphadenitis
A contagious and infectious disease, Caseous Lymphadenitis (also referred to as CLA, CL, boils, abscesses, cheesy glands) primarily affects the lymphatic system in sheep. Corynebacterium pseudotuberculosis is the bacteria which causes CLA – a disease which is typically observed when an abscess forms in the lymph nodes of a sheep. When this abscess is cut or ruptured, pus containing the bacteria will discharge. As Caseous Lymphadenitis spreads internally, ewes affected with this disease will lose weight dramatically.
CL is one of the leading causes of sheep causes getting condemned in the United States. Controlling the disease is a matter of culling visibly infected sheep from your flock and ensuring that hygienic practices are followed when your flock is sheared each year.
There is a CL vaccine for sheep, and it has been shown to decrease the number of sheep affected by Caseous Lymphadenitis and to diminish the number of affected lymph nodes in sheep that have CL, making it a good investment for shepherds.
Clostridial Diseases
There are several different types of clostridial disease common in sheep which are caused by clostridial organisms found in the soil where sheep live and graze. Most clostridial disease in sheep can occur naturally in the gut of sheep, passing to other sheep through bowel movements which are absorbed into the soil. Black leg, botulism, red water disease and malignant edema are some forms of Clostridial disease which can occur in sheep, but by far the most common forms of clostridial disease are enterotoxemia types C & D (overeating disease) and tetanus, also known as lockjaw.
Copper Toxicity
You may not be aware, but sheep are 10 times as likely to get copper toxicity than are cattle, and many salt licks and mineral supplements sold at your local grain and feed store are likely formulated primarily for cattle. This may cause them to have dangerous levels of copper which can cause copper toxicity in sheep.
When the levels of copper in a sheep become toxic the destruction of red blood cells occurs. Symptoms of copper toxicity in sheep include weakness and animals that suddenly go off their feed. Examine the sheep’s mucous membranes and white skin … if a yellowish brown color is present, and if urine is a red-brown color, your sheep may be suffering from copper toxicity. Treating copper toxicity in sheep involves the use of ammonium molybdate and sulfate compounds to bring copper levels back to a normal level.
Diarrhea
While it may sound mundane compared to the less-familiar sheep illnesses listed on this page, diarrhea can be one of the most deadly sheep diseases if left untreated and unattended. The causes of diarrhea in sheep are varied and can range from bacterial and viral infections, parasites, poor diet, and stress. The only way to accurately identify the cause of diarrhea in your sheep is to have a sample submitted to a lab for microbiological analysis, but shepherds can generally address it without lab work by doing some blanket treatments. These include isolating the animal that’s affected, de-worm them, monitor their diet, and provide plenty of fluids. If diarrhea continues it’s likely that the problem is bacterial or viral and antibiotics can be administered.
While diarrhea in sheep is less of an illness and more of a symptom of a more serious health condition, quick treatment and support of animals with diarrhea can play a major role in maintaining the animal’s health and conditioning. Diarrhea in sheep is not always a reason to panic, but continued diarrhea can lead to dehydration, weight loss, and put your sheep at risk of flystrike.
Dystocia
Dystocia in sheep is a blanket term which refers to any form of lambing difficulty. Difficult births can be caused by abnormal presentation of lambs, atypically large lambs, obese ewes, small pelvic areas or disease.
E. Coli Scours
The majority of time, E.Coli Scours is completely avoidable in your flock of sheep. It’s usually associated with a messy environment where your sheep are housed and poor sanitation in the barn. E. Coli Scours typically presents in 2-4 day old lambs which have diarrhea, produce excess saliva, and have a cold mouth when you insert your finger into it. “Watery mouth” is a common nickname for E. Coli Scours in sheep.
Due to the age of lambs affected by this disease, responding rapidly and aggressively is the best chance your lambs will have of survival. Rehydrate the lamb with oral fluids and nutrients like Nutri-Drench. Subcutaneous fluids may be administered in extreme cases to rehydrate the lamb quickly. Treat your lambs with the proper dosage of antibiotics as well.
Maintaining a clean, dry environment for your lambs is critical to avoiding this dangerous lamb disease.
Entropion
Entropion or “inverted eyelid” is a congenital condition which affects lambs. Lambs with Entropion will have the eyelashes of the lower eyelid roll in against the eye, causing the hairs and eyelashes to rub against the eye. Initially this will result in irritation which presents as your lamb having teary eyes. If left untreated, serious condition such as corneal ulceration, scarring and, ultimately, blindness will occur. Inverted eyelid can present in one or both eyes of lambs, and if you notice it in one lamb, it’s in your best interest to check the other lambs sired by their father … it’s common for the sire to pass this on to most of his offspring.
Treating entropion can be done in a couple of different ways, depending upon the severity. For less severe cases which are caught very early on in a lamb’s life, the most effective method is to use a fine needle to inject long-acting antibiotic under the skin of the affected eyelid. By injecting antibiotic between the layers of skin of the eyelid, the eyelid will expand and swell to accommodate the fluid, which forces the hairs and eyelashes to roll out normally and no longer irritate the lamb’s eye. Often, by the time the antibiotic fades later that week and the swelling goes away, the lamb’s eyelid muscles have corrected, and it will no longer be an issue.
For more serious cases of Entropion in lambs, staples, sutures or veterinary clips can be applied to roll the eyelid away from the eye, holding it there while the lamb’s eyelid muscles acclimate to this new position. It goes without saying that treating Entropion is a labor-intensive task which can be avoided by culling rams with the disease, and rams which sire lambs with the disease.
Epididymitis
This venereal disease in rams is caused by the Brucella Ovis bacteria. Inflammation of the epididymis on the testicles is how this presents and severely affected rams will have at least one enlarged epididymis and may exhibit pain when their testicle is manipulated. Epididymitis may cause infertility in affected rams, and it’s the top cause of infertility in the sheep industry. It is a contagious disease and can be transmitted between rams during homosexual activity, or during breeding season via the ewes.
Damage from Epididymitis is typically permanent in rams, and only about half of rams respond to treatment with antibiotics. Affected rams should be culled to avoid a permanent and ongoing problem which can affect your flock.
External Parasites
Ectoparasites, or external parasites in sheep, include flies, lice, mites, ticks and keds. Mange in sheep is rare in the United States, and any cases should be reported.
Sheep Keds — Keds are wingless, reddish-brown biting flies which closely resemble ticks. They’re often called ticks by those who don’t look closely. Like ticks, keds feed on blood and high ked populations can cause emaciation in your flock and make animals susceptible to other sheep diseases. Keds can only survive off of the animal for about a week, and treatment with insecticide immediately after shearing is recommended to knock down any ked population in your flock.
Lice — Sheep lice are small and difficult to detect since they spend most of their time on sheep right next to the skin. There are three species of lice which can be found on sheep, and while they’re difficult to see, you can sometimes become aware that you have a lice problem with your sheep when you notice excessive itching. Insecticides are the best treatment.
Fly Strike — If your sheep has scours for several days during fly season, be aware of the risk of fly strike. Flies will lay their eggs in the dirty, wet wool of your sheep’s posterior and when the eggs hatch, the blowfly maggots will burrow into your sheep’s wool and skin and live within the flesh of your sheep. Sheep are the most at-risk of fly strike of all domesticated mammals due to their wool. During fly season it’s recommended to keep your sheep clean and their back-end shorn to reduce the risk of wool contaminated with feces. If you notice one of your sheep has diarrhea which is on their wool, you should wash that sheep or shear it to prevent fly strike during the warm months when flies are present.
Nasal Bots or Flies — The Sheep bot fly deposits small larvae on the muzzles of sheep in or around their nose, and as the larvae develop they will migrate into your sheep’s nose and sinuses. Nasal bots present in sheep as a very snotty nose. If you notice sheep with a snotty nose which hold their head down and seek out corners to escape flies, then that animal may have nasal bots. Treating with insecticide which contains ivermectin is typically the best treatment.
Scabies or Mange — Sheep scabies or mange is an extremely contagious disease which is the result of small mites feeding on the surface of your sheep’s skin. Scabs develop due to the damage they cause, itching leads to hair or wool loss, with wool typically falling out in patches. Dipping your sheep in an insecticide bath is the preferred method of treating scabies or mange … but if you live in the United States the good news is your flock is likely safe as it has been eliminated here.
Facial Eczema
Fungal spores from perennial ryegrass and other dead vegetative material in pastures can cause liver damage which presents as facial eczema — a condition of severe dermatitis in sheep and cattle. This is a common sheep disease in New Zealand, Australia and South Africa. Oregon in the United States where irrigated perennial ryegrass fields exist, is another location where this condition can be observed. Treat affected sheep by removing them from the pasture, providing them with shade, plenty of water, and a good died. The addition of zinc to their grain can help as well.
Foot and Mouth Disease
Foot and Mouth Disease in sheep (FMD) is a viral, severe and highly contagious disease which affects sheep, cattle, swine, goats and other cloven-hoofed animals. This sheep disease presents with a fever and lesions which resemble blisters on the animal’s mouth and lips. Subsequently erosions of the tongue, lips, mouth, teats and between the animal’s hooves may be observed.
While the effects of Foot and Mouth Disease on adult sheep is typically minimal (you may not even notice it), young sheep affected by this disease are at risk of death. While it’s typically not harmful to humans, it is highly contagious and one case in your flock will likely mean that your entire flock will contract this disease. If you catch it early – try to isolate infected animals and remove and clean feed-pans and water buckets to try to prevent it spreading to the rest of your flock. Wash them in a diluted bleach solution.
Footrot
Footrot or Hoof Rot in sheep is an infection of the hoof caused by two types of bacteria. We have an in-depth article on footrot in sheep which covers the causes, symptoms and treatment of this disease as well as foot scald in sheep. We also have a useful article onhow to trim sheep hooves, which can help prevent diseases like hoof rot which cause lameness.
Grass Tetany
All ruminants are at risk of Grass Tetany – a disease which results from magnesium deficiency. Ewes are usually the members of your flock to be affected, and it’s likely that you’ll observe symptoms within 4-6 weeks of lambing. Symptoms include sensitivity to touch and trembling — most typically observed in the ewe’s facial muscles. Some ewes will be suddenly unable to move, or they may hobble and move stiffly about your barn or pasture. The most extreme cases of grass tetany in sheep will present when a ewe collapses and spasms with all four legs extended straight out.
Low blood magnesium levels which result in Grass Tetany are the result of low levels of magnesium in the ewe’s diet. The demands of lactation, a lush spring-grass diet which features low levels of magnesium or other mineral imbalances in their diet will be the culprit. Usually if a ewe has reduced magnesium levels, she’ll also have low calcium levels and treatment with calcium borogluconate and magnesium hypophosphite are the best path to recovery. Magnesium oxide is typically the cheapest supplement, and many producers will supplement their ewe’s food with 10-20 grams of commercial or homemade magnesium to prevent Grass Tetany in their flock.
Internal Parasites
Like external parasites, the list of internal parasites which can cause health issues in sheep is long. Each internal parasite can cause significant (and different) health concerns for sheep. In the broadest sense sheep internal parasites can be classified as worms, flukes, and protozoa. Here’s a short list of some of the most common types of internal parasites in sheep:
Cryptosporidiosis — This species of tiny protozoan parasites are related to coccidia and one of its major species can infect both humans and farm animals. This species, Cryptosporidium Parvum (or C. Parvum for short) has a rapid life cycle and infection occurs when oocysts are ingested. This most commonly occurs in lambs which are under a month old, though lambs as young as three days old can become infected. Symptoms of Cryptosporidiosis are a lack of sucking, diarrhea, and dehydration which can quickly be deadly if left untended. Illness from C. Parvum can last up to 10 days and relapses (even after your lamb appears to have recovered) are common.
Coccidiosis — Coccidia are single-cell protozoa, and what you may not know is that this form of internal parasite in sheep is commonly found in a sheep’s digestive system. These protozoa damage the lining of the small intestine which can prevent the absorption of nutrients for affected lambs. The most common symptom of Coccidiosis in sheep is diarrhea which could be bloody or smeared with mucous. This sheep disease is typically considered a management-related disease and results when sheep are housed in overcrowded areas or poor barn hygiene practices are observed. Include Lasolocid (Bovatec), Monensin (Rumensin), or Decoquinate (Deccox) in the grain you feed to prevent coccidiosis in your flock. If your lambs are affected treat Coccidiosis with Amprolium or Sulfa medications.
Stomach Worms in Sheep — Stomach worms are the most common type of internal parasites in sheep, and there are several different varieties which can infect your flock. The barber pole worm (Haemonchus Contortus) is the most common type of stomach worm in sheep with the small brown stomach worm being the next most likely culprit. These blood-sucking parasites pierce the mucosa of the abomasum (one of a sheep’s four stomach compartments), which causes blood and protein loss. As a result Anemia is a common condition affecting sheep infected with barber pole worms. An easy way to diagnose anemia in sheep is to take a look at the sheep’s lower eyelid. The eyelid will appear whiter in affected animals. An accumulation of fluid under the jaw (called “bottle jaw”) is another symptom. Diarrhea may also be observed, and you may also see worms in the stools of infected animals.
Several types of de-worming medications (like Ivermectin and Safeguard) are available, but some types of dewormers may not have an impact on the unique type of stomach worms present in your flock. This is why many shepherds use two or more brands of de-wormer, rotating them every month or every two months, so there’s regular, prophylactic coverage against all types of stomach worms which could affect your flock of sheep.
Nematodirus — This type of internal parasite differs from other worms in that it has a very short life-cycle and cannot survive for long outside of animals during warm, dry months. It’s therefore unlikely to occur in your flock during the summer. During cooler, damp months, however, Nematodirus larvae can survive in the pasture long enough to infect grazing animals. Scours and weight-loss are the early symptoms of this parasite.
Tapeworms (Moniezia) — If you see worms in the stools of your lambs or sheep, it’s likely that your sheep has tapeworms. There’s some disagreement among producers about the degree of impact tapeworms can have on your flock, but heavy infestations can cause diarrhea, weight-loss, and even intestinal blockages which can result in death. Suckling lambs are the most at-risk for tapeworms and benzimidazoles and Praziquantel (Zimectrin Gold) are the only anthelmintics which have been proven to be effective against tapeworms.
Lungworms in Sheep — If you’re treating your sheep proactively for stomach worms, the good news is that you’re also covered against lungworms in sheep. Infestation from lungworms is difficult to diagnose, and the only sure way to do it is during necropsy. Lungworms earned their name because they affect the respiratory system, though they’re passed from animal to animal through feces. As with all internal parasites, pasture rotation, providing clean water, and not overcrowding your flock are all key farm management practices which can reduce the likelihood of infestation.
Liver Flukes — Snails and slugs spread liver flukes in sheep, and the problem is much more common to flocks residing in low, wet areas. The affected animal will suffer liver damage, blood loss, diarrhea, and (ultimately) death. Clorsulon (contained in Ivomec Plus) and Albendazole (Valbazan) are the only two drugs which are known to successfully treat liver flukes, so it’s recommended that you use one of these as part of your flock de-worming program.
Meningeal Worms — This internal parasite is passed from white-tailed deer to sheep and other farm animals, even though domestic farm animals are not the standard hosts for this dangerous parasite. Infection occurs when grazing sheep ingest the Meningeal Worm larvae, at which point the larvae migrate to the animal’s spinal cord. Your sheep will have trouble walking and other neurological symptoms which could include paralysis. Sadly, when this deadly parasite reaches your sheep’s brain, it will kill its host.
There is no accurate way to diagnose Meningeal worm infection in a live animal, though when symptoms like those described above are observed you can suspect that this may be the cause. If you suspect your sheep has been infected with Meningeal worms treat it immediately with high doses of anthelmintics (de-worming medication) and anti-inflammatory drugs. The best way to prevent death due to meningeal worms is to have secure perimeter fencing (often we think of fencing as a means to keep sheep in a pasture, but you should also think of it as a means to keep deer and predators out). If preventing deer from entering your pastures is not possible, try to control the snail population in low areas of your pasture, as the Meningeal worm requires snails to complete its life cycle. The absence of snails will prevent larvae from infecting your flock.
Joint or Naval Ill
Joint Ill or Naval Ill in sheep commonly occurs in lambs that are 30 days old or younger. Affected lambs will be lame in several of their joints, most commonly joints in their legs. These joints will be hot to the touch and your lambs will act depressed, and they may be feverish as well. This sheep disease is caused when certain strains of streptococci enter its body, most commonly from an under-treated umbilicus, which is why treating the umbilical cord with a betadine or diluted iodine solution at birth is so important.
Laminitis
Lameness is the first symptom you’ll observe in cases of Laminitis, and the cause in this case is poor blood flow to the foot. If you handle the foot your sheep is favoring and it is warm to the touch, your sheep could have Laminitis. The cause of laminitis is an intake of grain which is too high (grain overload or acidosis). It’s important to know that if your sheep is limping that Laminitis may not be the only sheep disease which could cause these symptoms … in fact, it’s usually true that sheep affected by Laminitis die before the feet become involved. Proper nutrition and feedlot management is the key to preventing laminitis in sheep, and if your sheep is affected and you make changes in time, it is not uncommon for recovered animals to display abnormally large feet or permanent lameness.
Listeriosis
Listeriosis is caused by Listeria Monocytogenes, a bacteria which is widely available in nature and can be found in the soil, food sources, and even the feces of healthy animals. Most commonly, this sheep disease is observed as a result of feeding moldy or spoiled hay or silage, but even if you don’t feed silage or wet hay, it’s possible for your sheep to be infected as it is occasionally found in the environment.
This disease presents as inflammation of your sheep’s brain, and depression and disorientation are the first observable symptoms of this sheep disease. Listeriosis (sometimes called circling disease in sheep) can present as your sheep walking in circles, with its head tilted and part of your sheep’s face may appear paralyzed. The only way to treat this disease is with high doses of antibiotics, but generally treatment is not effective and the mortality rate for sheep with circling disease is very high.
Mastitis
An inflammation or infection of the mammary gland (udder) in ewes, Mastitis is sometimes also called “hard bag” or “blue bag” locally. Mastitis is caused by a bacterial infection – usually either Staphyloccus Aureus and/or Pasteurella Hemolytica. Mastitis in sheep is categorized either as acute or chronic. Ewes with acute mastitis will have mammary glands which could appear darker than normal, and the udder will also be quite warm to the touch. Ewes with acute mastitis may exhibit symptoms such as a hesitancy to walk, or they may hold up one rear foot due to the discomfort. It’s also not unusual that they balk at allowing their lambs to nurse due to the intense discomfort they are experiencing. On the other hand ewes with Chronic Mastitis may go undetected in your flock, as they don’t usually exhibit these tellin symptoms.
Treatments for mastitis in sheep usually involves a regimen of antibiotics which can be administered intramuscularly, or in some cases a veterinarian may administer intramammary infusions of antibiotics. There is no vaccine for mastitis and the best way to prevent ewes from contracting mastitis is to focus on effective flock management including good hygiene in your barn. Keep the bedding for lactating ewes clean and dry. It’s often the heaviest milking ewes which are more at risk for developing mastitis, and there may be a genetic component at play as well. Treating affected ewes with antibiotics and milking them to help clear the infection and keep them producing milk is usually the best method to treat sheep with Mastitis.
Measles in Sheep
Cysticercus Ovis, or measles in sheep, is a sheep disease associated with tapeworms which are in their intermediate or larval stage of development. There are no clinical signs of Cysticerosis or measles in sheep, and the only current method of diagnosing this sheep disease is at slaughter, when the cysts which result from this disease are evident. The risk of sheep measles is that farm dogs can develop tapeworms passed to them from the sheep by consuming droppings or sheep carcases. It’s very important that any dogs who have access to sheep farms are dewormed for tapeworms regularly.
Milk Fever
Milk Fever is a sheep disease which affects pregnant ewes which are approaching their delivery date. This is a time when calcium demands are highest for ewes as their lambs are developing their bone structure. Milk Fever results from inadequate intake of calcium in your ewe’s diet and symptoms of this disease are similar to what is observed in sheep which have pregnancy toxemia. The one difference which can help you determine that your ewe has milk fever and not toxemia is that sheep with milk fever will generally respond well (and quickly) to increasing the amount of calcium in their diet or administered subcutaneously (calcium gluconate). Milk fever is a sheep disease which is easy to prevent in your flock by ensuring that your pregnant ewes have access to plenty of calcium in their diet throughout their pregnancy, but particularly in the final months leading up to delivery.
Ovine Progressive Pneumonia (OPP)
Ovine Progressive Pneumonia or OPP in sheep is a viral disease which develops slowly. Sheep with OPP will exhibit weight loss, difficulty breathing, and sometimes lameness, paralysis or even Mastitis could be symptoms of OPP in sheep. Ovine Progressive Pneumonia in sheep is caused by a retrovirus and is transmitted to offspring through infected milk or colostrum, and while there is no treatment for this disease, it can be eliminated from your flock by participating in annual blood tests to identify infected animals which can then be culled.
At present it is estimated that over 50% of sheep flocks in the United States have an OPP infections, with anywhere from 1% up to 70% of flocks suffering from OPP infections. The majority of these infected sheep won’t be symptomatic, but identifying and culling sheep is the only way to prevent lambs or other members of your flock from contracting this potentially devastating disease. Veterinary lab testing is the only way to identify the disease with 100% accuracy.
Pink Eye
Pink Eye is a sheep infection which is important to be aware of and to watch out for – especially if you buy a new sheep from another farm, or regularly bring your sheep to county and state fairs where they share fencing with animals from other flocks, or are housed in pens that have been used by sheep and goats from other farms. Pink Eye is very contagious and affects the eyes of sheep. Once infected, the sheep with pink eye will be affected for approximately three weeks before the disease fully runs its course, and it’s critical that that animal be separated from your flock during this period so that your entire flock (and all of your sheep feeders, barn, and equipment) doesn’t become contaminated. There are no vaccines which are effective for preventing pink eye, and there is a risk of transmitting pink eye to humans from sheep and goats, so care should be taken when handling these animals to prevent developing pinkeye yourself. Eye medications containing antibiotics may accelerate the time-table for this infection in some cases, but results of this treatment aren’t consistent … usually this sheep disease simply has to run its course.
Pizzle Rot
Sheath rot or pizzle rot is a disease affecting rams, and it is an infection of the sheath of your ram’s penis. Corynebacterium Renaleor a similar bacteria is the cause of pizzle rot in sheep. Rams who consume a high-protein diet (usually a diet which consists of over 16% protein) are at higher risk for developing pizzle rot. Once rams develop this infection, the ammonia in their urine can cause very painful irritation and ulceration of the skin and debris from this ulceration can sometimes form a crust which blocks the opening of their sheath. Pizzle rot in rams can affect the desire of rams to breed ewes as the act will become very painful. Treatment with intramuscular antibiotics is effective.
Polioencephalomalacia
Polioencephalomalacia, also called PEM, CCN, or Polio in sheep, is a disease which affects your sheep’s central nervous system. Polio in sheep is caused by a deficiency in vitamin B1 … though it’s typically not the product of dietary deficiencies, rather the inability of the sheep’s body to utilize thiamine produced by the sheep’s rumen. If your sheep appears to be blind, or to gaze up at the sky blindly, your sheep may have polio.
The most common group of sheep to have Polioencephalomalacia are lambs which are consuming high concentrate diets in their creep, but it can also occur in any pasture sheep which consume plants which contain a thiaminase inhibitor (this can prevent proper metabolization of Vitamin B1. While the symptoms of polio in sheep will be similar to those observed with some other disease affecting your sheep’s central nervous system, diagnosis can usually be made following treatment with injections of vitamin B1. If your sheep responds to this treatment, you’ll know that they were suffering from polio.
Pregnancy Toxemia
Pregnancy Toxemia in sheep is a dangerous disease of pregnant ewes and you may have heard it called Ketosis, Twin Lamb Disease, Lambing Paralysis or Hypoglycemia locally. Toxemia in sheep is a disease which affects ewes late in their pregnancy and it’s a metabolic disease which will most commonly be observed in either thin ewes, fat ewes, older ewes, and ewes which are carrying two or more lambs. The cause of pregnancy toxemia in sheep is an inadequate intake of energy during the final stages of sheep gestation — a time when the bulk of fetal growth is occurring and the ewes need more nutrition to accommodate this fetal development.
Symptoms of Pregnancy Toxemia are usually listlessness, lack of energy, and eventually a lack of strength to stand and move around the barn. Treatment should be made right away, or you risk the health of the ewe and/or lambs as she will lack the strength to deliver her lambs. Treat ketosis in sheep by increasing the blood sugar supply of the affected ewe. This can be done by intravenous injections of glucose, and/or administering propylene glycol or molasses orally to the ewe with toxemia.
You can prevent pregnancy toxemia in your ewes by making sure late-term pregnant ewes are receiving sufficient food. Feed late term ewes at least ½ to 1 full pound of grain per day, and more may be required in large, high-producing ewes which have a history of delivering multiple lambs during each pregnancy. You should also ensure that each pen with pregnant ewes has adequate feeder space so that every ewe has easy access to the grain … otherwise smaller ewes may regularly be pushed aside and they might not be getting the nutrition they require.
Rabies
A viral disease which can affect sheep, Rabies is spread after contact is made between your sheep and saliva from an infected animal. Rabies is a central nervous system disease in sheep and usually results from bites or scratches, or when sheep have open wounds which come into contact with saliva from an animal with rabies.
Symptoms of rabies in sheep include when your sheep vigorously pulls at their wool. While there are vaccinations available for rabies, most flocks do not vaccinate for this disease because the risk of infection is low relative to the annual cost of vaccination. If you have a flock which contains very valuable animals (say you invested a lot of money in a stud ram), then you may choose to vaccinate those animals as a way to protect your investment. If you exhibit your animals publically, your state may require that those animals receive a rabies vaccination as well.
Rectal Prolapse
If you notice that your sheep’s rectal tissue is protruding from their body, this is an ailment called rectal prolapse in sheep. Early signs of rectal prolapse may appear to not be serious … these include a small round area which sticks out of your sheep’s backside when it coughs or lies down. In more extreme cases of rectal prolapse, the entire rectum may be pushed out of your sheep’s backside, and the sheep’s intestines may also pass through the opening. If this is the case, the disease may be fatal.
Factors which can lead to rectal prolapse in sheep include genetics, docking tails too short, chronic cough, stress, and sheep which consume high-concentrate diets are more at risk than others. Ewe lambs seem to be at higher risk than ram or wether lambs, and black-faced sheep seem to suffer rectal prolapse more frequently than their white-faced counterparts. Club lambs are at higher risk for rectal prolapse due to the extremely short tail docking and high-concentrate diet fed to most club lambs.
Ringed Cervix
A ringed cervix is generally the result of a traumatic delivery of lambs the year prior. Scar tissue develops on the cervix as a result of that delivery and the next time the ewe becomes pregnant this scar tissue prevents the cervix from fully dilating, which leads to difficulty lambing. Sometimes lambs can only be delivered via c-section as a result of a ringed cervix in sheep.
Ringworm
Ringworm in sheep is also called club lamb fungus or wool rot, and it is a highly contagious fungal infections of the sheep’s skin. While the name may lead you to believe ringworm is a type of parasite, it’s not … it is instead a fungal infection, and ringworm in sheep is primarily found on show lambs which are frequently slick-shorn. Infection is transmitted via fungal spores which are usually carried on contaminated sheep shears, blankets, combs or bedding, and while the ringworm lesions can appear anywhere on the animal, you’ll often observe them on the sheep’s head, neck or back. Antifungal agents applied topically can treat ringworm in sheep, but care should be taken when handling the animal, clippers used on the animal, sheep blankets, bedding or farm panels used to house sheep with ringworm, as club lamb fungus can cause an equally bad ringworm infection in people.
Ryegrass Staggers
Grazing animals who have access to perennial ryegrass are at risk of developing a sheep disease called ryegrass staggers. Ryegrass Staggers is a sheep disease which produces symptoms which range from muscle spasm to paralysis in sheep, and sheep contract this disease after metabolizing a specific group of toxins known to accumulate within the leaves of perennial ryegrass. These toxins are produced by ryegrass endophyte, a native fungus which frequently grows within the leaves, stems and seeds of perennial ryegrass.
If your flock has access to perennial ryegrass in their pasture and you notice animals with a stiff gait, or who develop difficulty walking (or become unable to walk), there’s a good chance they may have this sheep disease. Symptoms generally begin 1-2 weeks after your sheep has grazed on this plant, and extended exposure to this food source will likely produce permanent neurological damage to the animal. Younger sheep are considered to be more at risk than older animals which may have learned to avoid perennial ryegrass.
Scrapie in Sheep
Scrapie in sheep is a fatal neurological sheep disease which can also affect and be transmitted by goats. Scrapie is passed to lambs via their mother when the lambs come into contact with her placenta or the fluids associated with lambing. Bedding which has been wet with these fluids can also transmit the disease. There is no known treatment for Scrapie in sheep, and animals which have Scrapie will always die.
Thankfully, the occurrence of Scrapie in sheep flocks within the United States is low, but the disease is of regulatory concern to the US Department of Agriculture as it’s a member of a family of diseases referred to as TGE’s (Transmissible Spongiform Encephalopathies). Other disease in this family include Mad Cow Disease, Chronic Wasting Disease, and Creutzfeldt-Jacob’s Disease (in humans).
If you raise sheep it is recommended that you enroll your flock in the voluntary scrapie flock certification program. This program allows you to have your flock certified “Scrapie Free” after five years in the program, which consists of annual veterinary checks, and places limitations on what new animals you can or should bring onto your farm to add to your flock (encouraging producers to purchase breeding stock from other farms enrolled in the program). Having a certified scrapie-free flock is a great marketing tool for your flock, in addition to being a way to contribute to the national effort to combat this deadly sheep disease. Sheep can be genetically tested for scrapie resistance, though Scrapie is not strictly a genetic disease in sheep.
Spider Syndrome in Sheep
Spider Lamb Syndrome (SLS) in sheep is a genetic condition which will result in severe skeletal malformations in lambs. Sheep will only have Spider Lamb Syndrome when they inherit the recessive gene from both parents, and when that happens their bone will be extremely fine. Usually these sheep will have deformed and crooked legs, which are weak enough so that they can break under their own weight as the lambs grow heavier. Generally sheep with spider lamb syndrome do not survive to full maturity.
SLS in sheep is predominantly observed in black-faced sheep. It originated from a genetic mutation in the Suffolk sheep breed, and it spread rapidly due to the unique nature of this genetic disease. In most diseases like this, carriers (those with a dominant normal gene and the recessive gene of the disease) display no symptoms, but with carriers of Spider Lamb Syndrome, those who carried a single recessive gene often displayed rapid growth and larger bone structure than those who had two normal genes. As a result, SLS carriers often excelled in the show ring and were selected for breeding stock … which resulted in the spread of the disease within the Suffolk breed, and to other black-faced sheep breeds through crossbreeding programs.
There is a DNA test for the disease, and today animals with two normal (resistant) genes are favored by breeders, as having a flock without any carriers eliminates any risk for having spider lamb syndrome sheep born on your farm. Today, it’s nearly impossible to market your flock as free of the SLS gene if you sell breeding stock.
Urinary Calculi
Urinary Calculi in sheep refers to a metabolic sheep disease which affects rams and wether sheep. Rams with urinary calculi develop stones within the urinary tract which can be painful when passed during urination and (in serious cases) can result in a blockage of the urethra. This can result in retained urine, abdominal pain, and even rupture of the urethra or bladder … which will cause the ram to die.
Usually, the condition of urinary calculi or stones in rams will present when rams and wethers are fed grains with especially high phosphorus levels. The natural diet of sheep (forages, particularly leguminous plants), has a desirable ratio of phosphorus to calcium, whereas manufactured sheep food (grains), tend to have a very high level of phosphorus relative to calcium levels.
While some shepherds attempt to combat this discrepancy by offering free-choice mineral supplements to their rams as a method to prevent urinary calculi, this is not the recommended method, as there are no guarantees that rams will eat the available mineral supplements. Instead, shepherds should ensure that the ratio of calcium to phosphorus in the grain ration fed to their rams is at least 2:1. An additional step you can take to prevent urinary calculi in your rams is to add ammonium chloride to their diet and to ensure that rams always have access to an abundance of clean water. You can also add salt to their feed, which will increase thirst and ensure that your rams are consuming plenty of water.
Shepherds who invest a lot of money in high-quality stud rams should be especially diligent when it comes to managing the diet and water supply of these rams, as failing to do so can result in the death of an expensive stud at an early age. With proper diet and management, it’s likely that you can avoid having a ram with urinary stones.
Uterine Prolapse
A ewe may prolapse her uterus immediately after lambing. Uterine prolapse in sheep occurs when a ewe’s womb (uterus) is turned inside out and pushed through the birth canal due to the intense abdominal strainings of the ewe following labor. This is a life-threatening condition, so if this occurs to your ewe it’s critical that you (or your veterinarian) act swiftly to save the ewe.
If your ewe prolapses her uterus what you need to do is to push the uterus back inside of her — a challenging job since she will be straining against you the entire time, trying to expel it again. Before you begin there are several steps you should take:
First, you should raise the ewe’s hindquarters. This can be accomplished by stacking one or two bales of hay, and forcing the ewe onto her front knees and lifting her back end up onto the hay bales so her feet don’t touch the ground. With someone holding her head and placing some gentle weight on her shoulders this will keep the ewe stationary, and it also allows gravity to assist you when you return her uterus through the birth canal.
Second, it’s important that the uterus is clean before returning it to its rightful position. This will help reduce the risk of infection. You can use a disinfectant solution of warm, soapy water. Washing the uterus with this solution should be done before the uterus becomes dried out from exposure to the air, and before cold weather has the chance to damage the tissues.
Once the uterus is clean and the ewe’s hindquarters are raised, work to push the uterus back through the birth canal so it is inside her again. Since it will be inside out after she pushes it out, be aware that you’ll be pushing the side exposed to you in so that is the inside part of the organ again when it’s properly positioned inside her.
Finally, you’ll want to ensure that the ewe doesn’t simply prolapse again. This is a common risk, as the more trauma a ewe endures, the more likely it is that her body will send the signal that she needs to keep pushing. You can purchase a prolapse retainer (a small plastic device which is inserted into the ewe’s vagina and is secured around her torso with string to prevent her from prolapsing her uterus again). Be sure to wash the retainer with warm, soapy disinfectant before placing it into her body. After the uterus is returned to her and the retainer is secured, administer antibiotics to proactively knock down any resulting infection and you may also administer oxytocin. Ensure that she has plenty to eat and drink. It’s a good idea to add some molasses or propylene glycol to her water to ensure that she’s getting plenty of calories from her water to help her recover.
If you discover a uterine prolapse late, it’s not uncommon that the uterus will swell up considerably, which can make it difficult to return to the ewe’s abdomen. One home remedy which can help with this is that after you have disinfected the uterus with warm, soapy water, you can sprinkle some granulated sugar onto the uterus, which will help the tissues shrink back to nearly normal size. It’s not ideal to do this, but if you find that you are unable to return the uterus to her vagina at its current size, this is an option to make the process easier.
If you call a veterinarian to assist you, he or she may take one or two additional steps to ease the process of returning her uterus to its proper position, and to ensure that she does not prolapse again. Your veterinarian may give the ewe a shot in or near the spine to numb her so that she doesn’t push while he or she returns the uterus to the ewe. Your veterinarian may also use sutures to close the opening to the ewe’s vagina and prevent her from pushing the uterus out again after leaving your farm. Your ewe will still be able to urinate, but this is generally a more fail-safe way of preventing re-prolapse.
If handled and treated promptly, ewes who have prolapsed their uterus can often be kept in your flock and can deliver lambs again.
Vaginal Prolapse
In sheep, vaginal prolapses are commonly observed in pregnant ewes during the final months of pregnancy. Occasionally, you’ll see a ewe prolapse her vagina shortly after lambing. There are several common causes of vaginal prolapse in sheep, which can include hormonal or metabolic imbalances, a lack of exercise, sheep that are too fat or too thin, lambing difficulties during previous pregnancies, or an above-average amount of abdominal pressure due to large lambs. It’s not uncommon to observe vaginal prolapse repeatedly in the same ewe, during subsequent pregnancies.
When your ewe has a vaginal prolapse you should take some of the same treatment steps described above with uterine prolapse. Wash the exposed vagina with warm soapy disinfectant water and force it back into her vagina, using a prolapse retainer to prevent further prolapsing. If your ewe has already lambed, sutures are the preferred method to prevent re-prolapse.
Vaginal prolapse tends to be a hereditary issue, and while you may decide to keep a ewe after one vaginal prolapse to see if it recurs, if it does reoccur then you should cull that ewe and her offspring to prevent having to deal with this problem every year.
White Muscle Disease
White Muscle Disease (also called stiff lamb disease or WMD), is a disease which affects lambs and is the result of a deficiency of selenium or Vitamin E. This is a life-threatening disease if left untreated, so if you have a lamb exhibiting the symptoms of White Muscle Disease, you should treat it promptly with an injection of selenium and vitamin E.
It’s good practice to evaluate the feed rations of what you’re feeding your pregnant ewes to ensure that you are providing adequate levels of selenium and vitamin E to your flock. If your ewes aren’t getting enough of these minerals, it’s likely that you’ll see a number of lambs with stiff lamb disease. Supplementing the diet of your pregnant ewes is the preferred method of preventing white muscle disease, but you can also give them injections during pregnancy, or you can administer the appropriate dose to all of your lambs at birth if your flock has a history of white muscle disease. This can be given as a shot or (safer) an oral gel.
Generally, flocks in the North-eastern United States are most at risk, as there tends to be a lack of these minerals in forages in this part of the country.
http://www.raisingsheep.net/sheep-diseases.html
Flock vaccinations
Vaccinations are an important part of a flock health management program. They provide inexpensive “insurance” against diseases that can commonly affect sheep and lambs.
Clostridial Diseases
On most farms, the only universally-recommended vaccine for sheep and lambs is the CD-T toxoid. The CD-T toxid provides three-way protection against enterotoxemia caused by Clostridium perfringens types C and D and tetanus (lockjaw) caused by Clostridium tetani. There are 7 and 8-way clostridal vaccines that provide protection against additional clostridial diseases, such as blackleg and malignant edema, but the extra protection is often not necessary.
Type C
Enterotoxemia type C, also called hemorrhagic enteritis or “bloody scours,” affects lambs mostly during their first few weeks of life, causing a bloody infection in the small intestine. Type C enterotoxemia is often related to indigestion and is predisposed by a change in feed, such as beginning creep feeding or a sudden increase in the milk supply, perhaps caused by the loss of a littermate. The only way to protect lambs from type C enterotoxmia is to vaccinate their dams during late pregnancy.
Type D
Enterotoxemia type D is “classic” overeating disease. It is also called “pulpy kidney disease.” Type D enterotoxemia usually affects lambs that are over one month of age. Usually it is the largest, fastest growing lamb(s) in the flock that are affected. Type D overeating disease is usually precipitated by a sudden change in feed that causes the bacteria, already present in the lamb’s gut, to proliferate, resulting in a toxic, usually fatal reaction. Type D is most commonly observed in lambs that are consuming high concentrate diets, but can also occur in lambs nursing heavy milking dams.
Passive immunity
To confer passive immunity to lambs through the colostrum (first milk), ewes should be vaccinated with the CD-T toxoid approximately 4 weeks prior to lambing. Ewes lambing for the first time should be vaccinated twice in late pregnancy, four weeks apart. Maternal antibodies will protect lambs for six to eight weeks so long as lambs consumed adequate amounts of colostrum. It is recommended that a lamb consume 10 percent of its body weight in colostrum.
Lambs
Lambs should receive their first CD-T vaccination when they are approximately 6 to 8 weeks of age, followed by a booster 4 weeks later. If pastured animals are later brought into confinement or dry lot for concentrate feeding, a third vaccination should be given. Some experts recommned giving artifically-reared lambs multiple vaccinations.
Lambs whose dams were not vaccinated for C and D can be vaccinated with some success at two to three days of age and again in two weeks. However, later vaccinations will likely be more effective, as colostral antibodies usually interfere with vaccinations at very young ages. The lamb’s immature immune system may also not be able to respond to vaccination at such a young age.
A better alternative may be to vaccinate offspring from non-vaccinated dams when they are approximately 4 weeks of age, followed by a booster 4 weeks later. Anti-toxins can provide immediate short-term immunity if dams were not vaccinated or in the event of disease outbreak or vaccine failure.
Feeder lambs
Purchased feeder lambs should be vaccinated for type D enterotoxeia at the time of purchase and 2 to 4 weeks later. Feeder lambs purchased as 4-H or FFA projects should receive two type D vaccinations, if they were not vaccinated at the farm of origin.
Tetanus
Lambs whose dams were not vaccinated for tetanus should be given the tetanus anti-toxin at the time of docking and castrating, especially if elastrator bands are used. An antitoxin provides immediate short-term immunity. If a tetanus toxoid product is administered at the time of docking or castrating, it will not provide adequate immunity, as toxoids take 10 days to 2 weeks to provide immunity and require a booster for complete immunity.
Rams and pet sheep should be boostered annually with the CD-T toxoid. As with ewes, they require two vaccinations the first time they are vaccinated.
Other diseases
In addition to clostridial diseases, there are varous other diseases for which producers may wish to vaccinate. The use of additional vaccines depends upon the health status of the flock, the perceived disease risk of the flock, and prevalance of diseases in the geographic area where the flock is located. In the U.S. (for sheep), there are approved vaccines for sore mouth, foot rot, caseous lymphadenitis, abortion, e. coli scours, parainfluenza-3 (PI-3), epididymitis, and rabies. Vaccines that are not approved for sheep are also sometimes used.
Soremouth
There is a vaccine for soremouth (contagious ecthyma, orf), a viral skin disease commonly affecting sheep and goats. The vaccine is live. It causes sore mouth infection (lesions) at a location (on the animal) and time of the producer’s choosing. Ewes should be vaccinated well in advance of lambing. Show animals should be vaccinated well in advance of the first show.
To use the vaccine, a woolless area on the animal is scarified, and the re-hydrated vaccine is applied to the spot with a brush or similar applicator. Ewes can be vaccinated inside the ear or under the tail. Lambs can be vaccinated inside the thigh. Because the sore mouth vaccine is a live vaccine and sore mouth is highly contagious to humans, care must be taken when applying the vaccine. Gloves should be worn when handling the vaccine or animals with soremouth.
Flocks which are free from soremouth should probably not be vaccinated because the soremouth vaccine will introduce the virus to the flock/premises. Once soremouth vaccination is begun, it should be continued annually.
Footrot
Footrot is one of the most ubiquitous and economically devastating diseases in the sheep industry. It causes considerable economic loss due to the costs associated with treating it and the premature culling of carrier animals. There are two vaccines for footrot and foot scald in sheep: Footvax® 10 Strain and Volar™ Footrot Bacterin.
Neither vaccine prevents the diseases from occurring, but when used in conjunction with other management practices such as selection/culling, regular foot trimming, foot soaking/bathing, etc., vaccinations can help reduce infection levels. Footrot vaccines should be administered every 3 to 6 months, prior to anticipated outbreaks of hoof problems (i.e. prior to the wet/rainy season).
Abscesses (at the injection site) are not uncommon with the foot rot vaccines. The limitation of foot rot vaccines is that they might not include the strain of foot rot that is present in a particular flock. Foot rot vaccines are not always readily available.
Caseous lymphadenitis (CL)
There is a vaccine for caseous lymphadenitis in sheep. CL affects primarily the lymphatic system and results in the formation of abscesses in the lymph nodes. It is highly contagious. When it affects the internal organs, it evolves into a chronic wasting disease.
The cost of CL to the sheep industry is probably grossly underestimated. The CLA vaccine is convenient to use because it is combined with CD-T. Vaccination will reduce the number of abscesses in the flock, but it will not prevent the disease from occuring.
Abortion
Abortion is when a female loses her offspring during pregnancy or gives birth to stillborn, weak, or deformed lambs. There are vaccines (individual and combination) for several of the infectious causes of abortion in sheep: enzootic (EAE/Chlamydia sp.) and vibriosis (Campylobacter fetus).
Abortion vaccines should be administered prior to breeding. Ewes being vaccinated for the first time should receive a second vaccination (booster) in mid-pregnancy. Producers with problem flocks may consider giving a booster as well. Risk factors for abortion include an open flock and/or a history of abortions in the flock.
Unfortunately, there is no vaccine (available in the U.S.) for toxoplasmosis, another common cause of abortion in sheep. Since the disease-causing organism is carried by domestic cats, the best protection is to control the farm’s cat population by spaying/neutering and keeping cats from contaminating feed sources.
Epididymitis
Epididymitis is a major cause of reduced fertility in rams from western range states. There are vaccines for epididymitis (Brucella ovis), but none are deemed fully effective. In addition, vaccination interferes with the ability to eliminate infected rams from the flock, as vaccinated rams will test positive for B. ovis.
E.Coli Scours
Scours in baby lambs can be caused by E. coli. There is a vaccine that can be administered to ewes at the same time as CD-T to pass immunity to lambs through the colostrum. An alternative to vaccination is to give newborn lambs oral E. coli antibody at birth.
Rabies
Though the risk to sheep is usually minimal, rabies vaccination may be advised if the flock is located in a rabies-infected area, the animals are valuable, and livestock have access to wooded areas or areas frequented by raccoons, skunks, foxes, or other known carriers of rabies. Frequent interaction with livestock may be another reason to consider vaccinating.
The cost of the rabies vaccine relative to the value of the animals should be considered. The large animal rabies vaccine is approved for use in sheep. Producers should consult their veterinarian regarding rabies vaccination. Some states require rabies vaccination for exhibition at fairs and shows. All dogs and cats on the farm should be vaccinated against rabies.
Autogenous vaccines
When no commercial vaccine is available, autogenous or custom vaccines can be made. They are usually made from bacteria or viruses that have been isolated on a farm in conjunction with a disease. Autogenous vaccines are usually not as effective as commercial vaccines.
Giving Vaccines
Most vaccines are given subcutaneously (sub-Q), i.e. under the skin. Some vaccines are given intramuscularly (IM). Occasionally, some are given topically (e.g. sore mouth) or intranasally (e.g. Nasalgen®). For subcutaneous vaccines, use a 1/2 or 3/4 inch, 18- or 20-gauge needle. Subcutaneous vaccinations can be given over the ribs, behind the armpit, or high up on the neck. The needle used to withdraw vaccine from the bottle should not be the same needle used to inject the animal.
In order for vaccination programs to be successful, label directions should be carefully followed. Vaccines should be stored, handled, and administered properly. Only healthy sheep and lambs should be vaccinated. It is also important to note that vaccines have limitations and that the immunity imparted by vaccines can sometimes by inadequate or overwhelmed by disease challenge.
Future vaccines
With the increasing role of small ruminants in small farms and sustainable farming systems, hopefully animal health companies will develop and license more vaccines for sheep.
Scientists are currently working to develop vaccines to protect small ruminants againstHaemonchus contortus and other gastro-intestinal and blood-sucking parasites. The research is promising. Thus far, the challenge has been developing effective vaccines using recombinant DNA technology, as other methods of vaccine generation are not economically feasible.
Not vaccinating
Many sheep producers will tell you that they never vaccinate. Other producers vaccinate for diseases which are not a high risk. Vaccination is a form of risk management. Each producer must weights the pros and cons of vaccinating for a specific disease. If the cost of vaccination excees the expected losses, then vaccination is probably not cost-effective. Conversely, if expected losses exceed the cost of vaccination, then vaccination is a good risk management tool.
At the same time, it is not advisable to wait until you have a disease outbreak before instituting a vaccination program. The risk of a diseaes outbreak should be the criteria that is used to determine the need for vaccination. A producer’s tolerence for risk will also come into play.
http://www.sheep101.info/201/vaccinations.html
