How long do sheep usually live? What's the difference between sheep and goats? What do sheep see, hear, and smell? Mostly sheep eat grass, clover, forbs, and other pasture plants. How much wool does a sheep produce? What are transgenic sheep? What do they do with sheep's blood? How long do sheep usually live? Life expectancy Life expectancy is how long an organism is expected to live. Typically, the life expectancy of an animal increases with size. For example, cows usually live longer than sheep. The life expectancy of sheep is similar to large breeds of dogs, 10 to 20 years. The average is 10 to 12 years. However, the length of a sheep's productive lifetime tends to be much less. This is because a ewe's productivity is usually highest between 3 and 6 years of age and usually begins to decline after the age of 7. As a result, most ewes are removed from a flock before they would reach their natural life expectancy. It is also necessary to get rid of older ewes in order to make room for younger ones. In harsher environments (e.g. where forage is sparse), ewes are usually culled at a younger age because once their teeth start to wear and break down, it is difficult for them to maintain their body condition. It is possible for a ewe to be productive past 10 years of age, if she is well-fed and managed and stays healthy and sound. Aging sheep The approximate age of a sheep can be determined by examining upper incisor teeth. At birth, lambs have eight baby (or milk) teeth or temporary incisors arranged on their lower jaw. They don't have any teeth on their top jaw, only a dental pad. At approximately one year of age, the central pair of baby teeth is replaced by a pair of permanent incisors. At age 2, the second pair is replaced by permanent incisors. At 3 and 4 years, the third and fourth pairs of baby teeth are replaced. At approximately four years of age, a sheep has a full mouth of teeth. As she ages past four, her incisor teeth will start to spread, wear, and eventually break. When she's lost some of her teeth, she's called a "broken mouth" ewe. When she's lost all her teeth, she's called a "gummer." What's the difference between sheep and goats? Separating the sheep from the goats # Taxonomy While sheep and goats have many similarities, their taxonomy (scientific clasification) eventually diverges. Each is a distinct species and genus. Sheep (Ovis Aries) have 54 chromosomes, while goats (Capra Hircus) have 60. While sheep and goats will occasionally mate, fertile sheep-goat hybrids are rare. Hybrids made in the laboratory are called chimeras. # Look at their tails The easist way to tell the difference between a sheep and goat is to look at their tails. A goat's tail goes up (unless it is sick, frightened, or in distress). Sheep tails hang down and are often docked (shortened) for health and sanitary reasons. # Foraging behavior The biggest difference between sheep and goats is their foraging behavior and diet selection. Goats are natural browsers, preferring to eat leaves, twigs, vines, and shrubs. They are very agile and will stand on their hind legs to reach vegetation. Sheep are grazers, preferring to eat short, tender grasses and clover. Their dietary preference is forbs (broadleaf weeds) and they like to graze close to the soil surface. Goats like to eat the tops of plants. # Behavior There are many behavior differences between sheep and goats. Goats are naturally curious and independent, while sheep tend to be more distant and aloof. Sheep have a stronger flocking instinct and become very agitated if they are separated from the rest of the flock. Goats will seek shelter more readilty than sheep. Neither likes to get their feet wet and both prefer upland grazing to lowland. In a fight, a ram will back up and charge to butt heads. A goat will rear up on his hind legs and come down forceably to butt heads. This fighting behavior favors the ram. # Physical differences Sheep and goats have many physical differences. Most goats have hair coats that do not require shearing or combing. Most sheep grow wool and need to be sheared annually. Lamb tails are usually docked (shortened) whereas goat tails are not. Sheep have an upper lip that is divided by a distinct philtrum (groove). The goat does not. Male goats have glands beneath their tail. Sheep have face or tear glands beneath their eyes and foot or scent glands between the toes. Male goats develop a distinct odor as they grow in sextual maturity. The odor is very strong during the rut (mating season). Sexually mature rams have much less of an odor. # Horns Most goats naturally have horns. Some goats have beards. Many breeds of sheep are naturally hornless (polled). Some sheep have manes. Goat horns are more narrow, upright, and less curved than sheep horns. Sheep tend to curl their horns in loops on the sides of their heads. Sheep and goat production # Reproduction The estrus cycle of the ewe averages 17 days; 21 days for the doe. Goats are much easier to artificially inseminate (breed) than sheep. Sheep have a complicated cervix which makes passage of an insemination rod very difficult. Sheep show few visible signs of estrus (heat) as compared to goats. Male goats have an offensive odor during the mating season; rams do not. Though it varies by breed, goats tend to be less seasonal and more prolific than sheep. # Nutrition Sheep and goats have similar nutrient requirements, though goats have slighter higher maintenance requirements, as they are usually a smaller animal (by weight). Sheep tend to grow much faster than goats, no matter what the diet is. They convert feed more efficiently. Grain-feeding is less likely to be profitable in goat production. With the exception of hair sheep, sheep and goats fatten very differently. Goats deposit fat around their internal organs before depositing external fat. Sheep deposit external fat before depositing internal fat. Finn sheep and some of the hair breeds deposit fat around their organs similar to goats. Sheep have a narrow tolerance for excess copper in their diet, though toxic levels depend upon the availability of other minerals (Molybednum and Sulfur) in the diet. It is recommended that sheep be fed grain and mineral mixes that have been specifically formulated for sheep, as products formulated for other livestock or generic livestock feeds will likely have added copper. It can also be risky to graze sheep on pastures that have been fertilized with poultry or hog manure. It is not advisable to use copper as a deworming agent. Goats have require more copper in their diet than sheep and are not as sensitive to copper toxicity. When co-mingled, sheep products should be fed. # Diseases Sheep and goats are generally susceptible to the same diseases, including scrapie, which is transmitted via infected placenta to genetically-susceptible animals. Sheep and goats are infected by the same internal parasites (worms), though coccidia are species-specific. Goats tend to be more susceptible to worms than sheep, due to their origins and natural browsing behavior. Goats metabolize anthelmintics quicker and require higher doses of the drugs. The clostridial vaccines also seem to be less effective in goats. Fewer drugs are FDA-approved for use in goats. OPP (ovine progressive pneumonia) and CAE (caprine arthritic encephalitis), are similar diseases, caused by a slow virus like HIV, that affect sheep and goats, respectively. The primary mode of transmission is through the colostrum. Cross infection is possible. # There is no disease similar to "floppy kid syndrome" in lambs. # Social dominance Due to their more aggressive behavior, goats will usually dominate sheep, especially if the goats have horns. However, when young bucks and rams are maintained together, rams will dominate because the ram will preemptively strike the buck in the abdomen while the buck is still in the act of rearing up. What do sheep see, hear, and smell? Sheep Senses # Because they are a prey animal, sheep require excellent senses to enhance their chances of survival in the wild. # Vision Sheep depend heavily on their vision. They have excellent peripheral vision and can see behind themselves without turning their heads. However, they have poor depth perception. They cannot see immediately in front of their noses. Some vertical vision may also have been sacrificed in order to have a wider field of vision. For example, it is doubtful that a sheep would be able to see something in a tree. # Color perception Contrary to previous thought, sheep and other livestock perceive colors, though their color vision is not as well-developed as it is in humans. Sheep will react with fear to new colors. # Hearing Sheep have excellent hearing. They can direct their ears in the direction of a sound. Sound arrives at each ear at slightly different times, with a small difference in amplitude. Sheep are frightened by high-pitched and loud noises, such as barking dogs or firecrackers. # Smell Sheep have an excellent sense of smell. They are very sensitive to what different predators smell like. Smell helps rams locate ewes in heat and ewes locate their lambs. Sheep also use their sense of smell to locate water and determine subtle or major differences between feeds and pasture. # Taste The sense of taste in sheep is probably not as important as the other senses. However, sheep have the ability to differentiate different feedstuffs and taste may play a role in this ability. When presented with a variety of feeds, sheep will select certain feeds over others. Sheep will select different types and species of plants than other livestock. # Touch Since the sheep's body is covered with wool or coarse hair, only the nose, lips, mouth, and maybe ears readily lend themselves to touching behavior. However, touching is important to the interaction between sheep. Lambs seek bodily contact with their mothers and the ewes respond to touching in many ways, including milk letdown in response to the nuzzling/suckling stimulus of lambs. When young lambs sleep, they will seek out their mothers and lie close to them. # Grass, clover, and forbs Mostly sheep eat grass, clover, forbs, and other pasture plants. They especially love forbs. It is usually their first choice of food in a pasture. A forb is a broad-leaf plant other than grass. It is a flowering plant Forbs are very nutritious. As compared to cattle, sheep eat a greater variety of plants and select a more nutritious diet, but less so than goats. # Grazing time Sheep will graze for an average of seven hours per day, mostly in the hours around dawn and in the late afternoon, near sunset. When supplements are fed, it is best to feed them in the middle of the day so that normal grazing patterns are not disrupted. # Different plants Sheep in different geographic areas eat different plants. Tropical forages are usually not as nutritious as those that grow in temperate climates. Protein is often the most limiting nutrient in forages. All forages are more nutritious if they are eaten in a vegetative state. # Pasture requirements The amount of pasture or range land that it takes to feed a sheep depends upon the quality of the land (soil), the amount and distribution of rainfall, and the management of the pasture. In dry climates, an acre (or hectare) of pasture or rangeland cannot feed as many sheep as an acre of pasture in a moist climate. An acre of pasture in the wet season (spring and fall) can obviously feed more sheep than an acre in the dry season (usually summer) Reproductive rates and lamb growth rates are lower in arid climates than high-rainfall areas that grow more plentiful forage. As a result, wool production tends to be of greater importance in these environments, as it takes less nutrition to grow good quality wool than to raise lambs and produce milk. A farmer may be able to graze ten sheep on one acre of improved pasture in Maryland, whereas one sheep could require ten acres of native range in West Texas. # Stored feed When fresh forage is not available, sheep are usually fed stored and harvested feeds: hay, silage, or crop by-products. Hay is grass that has been mowed (cut) and cured (dried) for use as livestock feed. Silage (short for ensilage) or haylage is green forage that has been fermented and stored in a silo or other system that keeps air out. Moldy silage can cause listeriosis in sheep. The pieces should be chopped smaller for sheep as compared to cattle. Sometimes, pasture plants are cut, chopped, and brought to the sheep. Fresh harvested forage is called green chop. This "cut-and-carry" system of feeding is common in developing countries. # Supplementing with grain Grain is often fed to sheep with higher nutritional needs, such as pregnant ewes during late gestation, ewes nursing two or more lambs, and lambs with the genetic potential for rapid growth. Grain is the seed part of cereal crops such as corn, barley, wheat, and oats. A protein source, such as soybean meal or cottonseed meal is usually added to the grain ration, along with vitamins and minerals to make a 100 percent nutritionally-balanced feed. Unbalanced grain rations can lead to a variety of health concerns. Sheep love the taste of grain and can get sick if they eat too much grain too fast. Grain consumption needs to be regulated, introduced slowly and gradually increased. Ruminants should always have some roughage in their diets. at least a pound per day for sheep. Producers in many parts of the world cannot afford to feed grain to their livestock. # By-products By-products from crop production and food processing can also be fed to sheep. Examples include soybean hulls, peanut hulls, and whole cottonseed. With more corn being used in the production of ethanol, distiller's grains are becoming a more popular feedstuff for sheep and other livestock.