IACUC Learning Module - Sheep and Goats | Previous Next |
Sheep and goats housed within University Animal Care facilities will be maintained on pelleted feed, rather than hay and grain. The primary reason is that floor drains in animal rooms will be blocked by the hay stems, resulting in higher operational costs which result in higher daily cost to the investigator. In addition, the pelleted diet is consistently formulated, versus the variation observed in hay sources.
Sheep are inclined to eat most anything that is offered to them and may kill themselves by overeating. Sheep need to be fed a fixed amount on a regular basis and any changes must be gradual.
Never give sheep 3 days worth of grain or hay to last it over the weekend. This general rule applies to all farm animals, but the sheep is particularly prone to overeating.
A disease called Enterotoxemia, or overeating disease may occur in sheep, goats and less frequently cattle. It is due to an imbalance in the populations of various species of rumen bacteria; this imbalance most often occurs as a result of overfeeding of grain, or less often due to a sudden switch in feed sources.
Reduced appetite may also be a serious sign of a veterinary crises, especially in pregnant ewes near the time of parturition. Pregnancy toxemia occurs when a pregnant ewe must switch from normal energy sources (hay, grass or grain metabolized into glucose) to stored energy sources (fat and muscle). Anything that interrupts the normal feed intake of pregnant ewes, such as transport, other illnesses, rain storms, may result in this metabolic switch. The early clinical signs include loss of appetite, listlessness and stumbling. Prompt veterinary attention must be obtained because the disease is difficult to treat once it has progressed past the initial stages.
Goats are more selective about what they will eat (despite the old wive's tales) and will often refuse soiled or dusty food. Although less likely to overeat than sheep, they still may do so, especially on grain or other tasty food sources. Goats are extremely curious and willing to spend hours to manipulate with their mobile lips a wide variety of locks and latches. Secure "goat-proof" latches should be on pens, feed-room doors and feed barrels.
Sheep and goats on a dry feed diet usually have hard-pelleted manure. If they are on green feed or a heavy grain diet with molasses, the manure may become soft and non-pelleted. Animals on lush green grass might have diarrhea simply due to the high water content, but diarrhea is usually indicative of disease and veterinary attention should be sought. (Many stockmen use the word "scours" to describe diarrhea).
Urine is yellow and clear. Female sheep and goats squat to urinate. Intact males tend to urinate in spurts, whereas castrated males tend to have a more constant flow. Any interruption or slowing of urine flow should be reported to the unit supervisor and Farm Animal Veterinarian. Additional signs of blockage of the urinary tract include: restlessness, twitching of the tail and straining during urination. If the obstruction is not corrected, the urethra may rupture and urine be deposited within the abdomen or in the subcuticular spaces. This is commonly called. "water belly". Obstruction of urine will kill male sheep or goats.
Most of the breeds of sheep common in America lack horns. Goats are routinely dehorned at birth. A hot debudding iron is used to destroy the "bud" of the horn, before the horn cells proliferate. Goats of either sex may be born with wattles, nonfunctional pendants of skin which hang from either side of the neck. Wattles can be injured by being caught on fences or feed bunks so sometimes they are removed at the time of dehorning by snipping them off with sterile scissors.
Both sheep and goats need their feet trimmed regularly. If the feet are neglected, the animal may go lame. Caretakers need to examine feet on a regular basis and report injuries such as sole ulcers or coronary band cuts to the veterinarian.
Never put a freshly shorn sheep outdoors if not acclimated to the temperature (be certain to check the seasonal, nightly low temperature since it may be 40 cooler than the daytime). In Arizona, one must also guard against a newly shorn animal becoming sunburn by being placed in direct sun.
Adult, intact males become increasingly difficult to handle as breeding season approaches and they get smellier due to special scent glands. Goat bucks may urinate on their own body and have foul smelling scent glands just behind their horns, which they rub on objects to mark their territory.
Young male sheep and goats are born with descended testicles. Unless being kept for breeding purposes, most males are castrated, often at birth by using hard rubber bands placed around the entire scrotum. It is imperative that sheep receive an injection of Tetanus Antitoxin at the time of castration.
The tails of both sexes are shortened or "docked" at a few days of age by using a hot iron or blade. The tail is removed to keep the animal more clean and by reducing manure, reduce the likelihood that flies will lay eggs in the matted, fecal encrusted hair.
For both of these routine husbandry procedures, be certain to watch for signs of infection (pain, redness, discharge) and report to the unit supervisor any adverse reaction. Problems will usually be apparent within a few days of the procedure.
Sheep and goats are polyestrous, cycling mostly in the fall, although certain breeds have greatly extended breeding seasons. Estrus cycles in the sheep are about 16 days and the goat about 21 days.
Onset of puberty usually occurs in the first breeding season after birth, but if born late in the year, a ewe may not show signs of heat until the following breeding season. Gestation period is about 5 months. The average age of weaning for lambs and kids is 6-10 weeks.
Lambing is usually in the spring and either one or two lambs are born. Lambing areas should be clean, without drafts and well bedded. As parturition approaches, the ewe's udder will fill with milk.
She may be restless and separate herself from the flock. She may paw the ground, urinate, and frequently get up and down. As contractions begin, the water bag protrudes from the vulva and breaks. Lambs normally present forelegs first, with the head lying on the forelegs. Parturition should take about 30-45 minutes with twins being born about 10-20 minutes apart.
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SQ Subcutaneous Injections are usually made in the loose skin where the neck and shoulder join. IM Intramuscular Injections may be given in the thigh muscle or the large muscles along the side of the neck. IV Intravenous Injections are usually done in the jugular vein. The vein can be distended by manual occlusion of the vessel below (toward the heart) the intended venipuncture site. |
Ruminant anesthesia poses problems. When asleep, ruminants are likely to regurgitate some of the rumen contents into the mouth and they may drain down the trachea into the lungs and cause a deadly, aspiration pneumonia. Endotracheal intubation is recommended to prevent this problem.
In addition, the rumen continues to ferment and produce gas while the animal is anesthetized, but due to being asleep, the animals is no longer belching (eructation) to reduce the gas buildup. Therefore, gas pressure, called "bloat", can increase to the point that the diaphragm can't contract and expand and the animal may have respiratory distress. Not allowing the animal food for 24 hours prior to anesthesia helps to reduce these problems; the veterinarian should be consulted.
The most common health problems observed with sheep at the University farm include:
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Last updated: 01/02/2008 gea
