|Auburn University Digital Library|
|Microlivestock - Little-Known Small Animals with a Promising Economic Future|
source ref: b17mie.htm
|Part I : Microbreeds|
Among the hundreds of breeds of sheep (Ovis aries) in the world, those weighing less than 35 kg when mature have been largely ignored. Although these are common, the impression lingers that they are too small to be useful. Yet this virtually untapped gene pool is esnecially well adapted to traditional Third World animal husbandry. Given attention, these "microsheep" could boost meat, milk, skin, wool, and pelt production in many villages and small farms of Africa, Asia, and Latin America.
Many microsheep thrive in environments that tax the ability of larger breeds to survive. They are adapted to poor feeds and can be grazed in uncultivated wastelands unsuited to any other livestock except goats or camels. Because of their size, microsheep can fatten in areas where forage is so scattered and sparse that larger animals cannot cover enough ground to fill their bellies each day. In addition, their foraging complements that of other livestock. For example, sheep can graze rough grasses and weeds that cattle find unpalatable. Some survive even the stress of extreme aridity and for this reason are the predominant livestock in North Africa and the Middle East.
Many small breeds can be disease resistant. Some, for example, are widespread in the zones of Africa where trypanosomiasis is prevalent. They are generally less adversely affected by foot-and-mouth disease than are cattle, and some small native sheep seem to have fewer problems with insects and parasites than do most other livestock, including temperate-area sheep.
Giving more attention to the management and improvement of microsheep could pay back abundantly in the form of food, income, and improved land utilization in many parts of the developing world.
AREA OF POTENTIAL USE
Worldwide, but notably in drier regions of the tropics.
APPEARANCE AND SIZE
An average weight for temperate sheep breeds is about 70 kg,' but the smallest microsheep weigh less than 20 kg fully grown. Many tropical microsheep are "hairless," and have little or no wool. These are often difficult to distinguish from goats, but (like all sheep) they generally have blunter snouts, more fat, and hanging tails. Some have greatly enlarged rumps or tails that store fat. Unlike goats, sheep have no odor-producing glands.
Some representative microsheep are described at the end of this chapter.
More than one billion sheep occur worldwide, and they occupy every climatic zone in which people live. At least half are in developing countries.
Although more than 1,000 breeds are recognized, only a handful dominate the world's sheep industries. Lesser-known breeds are rapidly becoming extinct (especially in developed countries, although scattered efforts are being made to preserve them). Elsewhere, genetic resources have not been properly evaluated, and potentially valuable stock is being lost before it is even understood.
HABITAT AND ENVIRONMENT
Sheep are among the most adaptable animals. Various types are kept in areas of extreme heat, cold, altitude, aridity, humidity, and rainfall. They are especially widespread in hot, dry climates, but some breeds also thrive in humid areas.
Sheep make efficient use of a wide variety of fodder: tree leaves, fortes, grasses, crop residues, and agricultural by-products, for instance. They often survive privation by calling on their reserves of body fat.
In the tropics, sheep reach sexual maturity in about a year. Many breeds lamb year-round, which allows for a continuous production of premium meat. Gestation takes about five months, and lambing is usually timed to occur when feed is most abundant and nutritious. Microsheep often bear two or more young and, under good management, may produce lambs annually for more than five years.
These shy animals flock together and, in general, are managed with little effort. They are easily panicked, however, and rams can become aggressive during rutting or when threatened.
THE LITTLE SHEEP THAT COULD
Dozens of the world's neglected breeds of tiny sheep should be preserved from extinction, for many will undoubtedely prove to have outstanding qualities. Current efforts to save the Navajo sheep in the United States exemplify what can be achieved
The Navajo is a microsheep, and is perhaps the oldest breed of sheep in the United States. It may have been introduced to North America in 1540 by the Spanish explorer Francisco Vazquez de Coronado, who was seeking the mythical Seven Golden Cities of Cibola in the region that is now Arizona and New Mexico. Smaller than many dogs, a full-grown Navajo sheep may weigh only 30 kg, but it became a big part of the culture of the Southwest. Although the Navajos and other local Indians had never seen sheep before the 1500s, they soon became shepherds and weavers, and their rugs made from the unique wool of this wiry little animal remain famous even today.
Navajo sheep have white or brown wool hanging in ringlets around their bodies. The fleece is a double coat: long, coarse guard hairs on the outside and short wool on the inside. It yields warm, waterproof, and long-lasting products. Many of the sheep have four horns because the Indians believed that this trait was sacred, and they favored four-horned rams for breeding purposes.
The number of Navajo sheep was reduced sharply between 1950 and 1950 because of severe overgrazing and replacement by improved wool breeds. In recent times there has been so little commercial and scientific interest in this microsheep that by the 1970s only a handful of purebred specimens survived. Since the late 1970s, however, Lyle McNeal, a Utah State University professor, has been working to save it from extinction. By 1988 he had a burgeoning flock at the university and was learning that this supposedly obsolete dwarf is amazingly useful.
The breed originated in the arid south of Spain (where it is called the "churro"), and it thrives in the hot, dry climate. Unlike normal breeds, it can exist in the desert without supplementary food and with little water. As McNeal has pointed out, any sheep that can survive and raise a lamb in the aridity and searing heat of the American Southwest has to be superior. He has found that the ewes have a strong maternal instinct, which is vital for protecting lambs against the coyotes that are common in the region.
Thanks to the efforts of McNeal and his colleagues, Indians are beginning to use Navajo sheep again; by 1988 there were more than 400 on the Navajo reservation, with their wool fetching premium prices. This tough little sheep could prove valuable not only for American Indians but for poor people in many other dry regions as well.
Microsheep are mainly kept for meat production, but - especially in arid regions - for milk as well. Their meat is usually lean with little "muttony" taste.
Wool or hair is taken from many breeds, although the yield is often small. Skins from hair sheep' thinner than cowhide, are widely used and are in international demand. In some places, manure is considered an important product. In Nepal, thousands of small sheep are used as pack animals, especially to carry salt into mountain valleys.
Most sheep are maintained in free-ranging flocks. Many are grazed (often tethered) over a small area during the day and confined in a "fold" at night. Others are penned or kept as village scavengers. These are usually fed supplements of household scraps.
Sheep form an integral part of a mixed farming economy; for example, they may graze pastures during the wet season, and survive on crop residues and field weeds during the dry season. They have excellent foraging capabilities and are often kept alongside goats. This broadens the variety of forages utilized and often increases total production from a single piece of land, for sheep and goats have complementary feeding habits and male goats help protect the sheep from some predators.
In spite of the heavy toll that predators (such as feral dogs) can take on lambs and ewes, the largest proportion of sheep in the tropics are lost through lack of basic care. Modest supplemental feeding of lambs and inexpensive preventive medicines can do much to lower mortality and boost production.
Sheep are multipurpose animals, and almost everywhere they produce several products. The rich milk is often preferred to that of cows or goats, especially for making cheese and yogurt.
Lambs form an important part of the household economy for much of the rural world, and only rarely is social or religious stigma attached to keeping or eating them. Indeed, sheep are the traditional feast animals of several religions, and in some places sheep meat is preferred to beef and sells at a premium.
By and large, all sheep products can be processed, utilized, or marketed by the producer. In addition, sheep marketing and transportation systems exist in most countries, at least to some degree.
Sheep are efficient producers and can provide a quick turnover for food and cash. On the brush and coarse grasses of marginal lands, they may be more productive than cattle, and on grass they may outproduce goats. As long as they are not overstocked, sheep do not degrade vegetation; unless starving they will not debark trees. Small breeds cause little erosion, even on steep slopes, heavily traveled paths, or near water holes.2 In South Asia, they have been continuously stocked on the same ground for thousands of years without causing apparent harm.
Because sheep have a natural tendency to accumulate fat, they "finish" well on grazing and usually do not require a high-energy finishing diet.
Despite their general healthiness, sheep are affected by many internal parasites and diseases, a few of which are communicable to man. They are especially susceptible to infectious conjunctivitis (pinkeye).
Predators and thieves can be greater threats than sickness. Labor inputs can be high because of the almost continual protection sheep need.
Some mutton has a strong taste that many find unappealing. However, the taste is carried mainly by the fat, and the generally lean microsheep are often commended for their fine-textured, sweet meat.
RESEARCH AND CONSERVATION NEEDS
The numerous breeds of small sheep should be investigated. Assessments should be made for the animals' ability to thrive under adverse conditions and for resistance to particular diseases and parasites.
As noted, even minimal extension services and veterinary support for sheep could greatly decrease mortality, especially among lambs.
Improving microbreeds without increasing their size is one of the most interesting challenges facing sheep scientists today. While efforts should be made to conserve and select within types, research should also be conducted on hybrid vigor. Efforts to improve the pelt and fleece of microsheep should also be encouraged.
More studies on the interactions between sheep and cropping systems are needed. Sheep (and the manure they produce) could become important components of forestry (see sidebar), crop rotation, alley cropping, and other forms of sustainable agriculture. For instance, sheep are especially effective for weed control in plantation crops such as oil palm and rubber as well as in forests.
SMALL SHEEP IN THE FOREST
Even in countries with long traditions of raising large sheep, there are opportunities for using small, agile, hardy breeds. The following is an example.
Seeking safer methods for stopping brush from smothering newly planted trees, U.S. government foresters have turned from chemical defoliants to flocks of sheep. Court decisions in 1983 and 1984 barred the use of herbicides along Oregon's Pacific Coast. Various alternatives were tried, and the animals proved the most successful. Sheep are now the favored method for controlling unwanted vegetation. Indeed, they have changed the foresters' whore approach to managing reforestation.
Formerly, the U.S. Forest Service allowed the brush to grow on logged-over sites and then sprayed it down before planting tree seedlings. Now it plants grass to suppress brush and reduce erosion. The sites are later fertilized, tree seedlings are planted, and within a year sheep are brought in to graze.
Today, in the district around Alsea, Oregon sheep nimbly skirt old stumps to graze on the lush vegetation. Three times each summer since 1984, about 2,000 sheep have been guided across the replanted areas by a herder and a range conservationist. The sheep eat both the grass and the new buds on brush, but they leave most fir-tree seedlings untouched. The key, according to Rick Breckle, a forester, is to have enough sheep to graze an area evenly and to keep them moving so they don't resort to nibbling the young trees.
Previously, chemical brush treatments had annually cost $135-$353 per hectare. Now, sowing grass and grazing sheep costs about $300 per hectare. And there is a product to sell: the adult sheep don't fatten well, but the lambs bring a useful income at the end of the summer. What is more, Breckle reports that the trees seem to be growing faster - probably because of the manurings they receive.
This method seems likely to be effective elsewhere - at least with trees that are unpalatable or too tall for their growing points to be nibbled. Malaysia, for instance, doubled its sheep population between 1986 and 1989, in part because it has begun raising sheep between the trees in rubber plantations. With the use of agroforestry increasing worldwide, small sheep could find a whole new application.
REPRESENTATIVE EXAMPLES OF MICROSHEEP
West African Dwarf
Senegal to Nigeria, and south to Angola. Female 25 kg; male 35 kg. Well adapted to warm, humid conditions. Prolific, and good disease resistance. Major meat producer in West Africa. Fast growing: by six months of age they approach adult weight.
Landim (Small East African)
East and Central Africa. 23-40 kg. Prolific, adaptable, long fat-tailed type. Large litter size for a sheep. In one recent test, ewes averaged more than 1.4 lambs.3
Atlas Mountains. 25-41 kg. Needing little feed and remaining constantly outdoors, these extremely hardy sheep are exploited for meat and their coarse, hairy wool. They fatten easily when well fed.
North Africa. 40-50 kg. This thin-tailed sheep is exceptionally robust, and is resistant to extremes of temperature, drought, and poor nutrition. Primarily a meat producer, its wool is used for coarse cloths and carpets.
Southern Sudan Dwarf
One of the many small breeds of eastern and southern Africa, its weight ranges from 15 to 25 kg, but it may weigh as little as 11 kg. Yielding a fine, short fleece, this hardy, frugal sheep is often run with cattle to maximize grazing.
Deserts of Arabia. 32 kg. A popular and ancient fat-tailed meat producer that is highly acclimatized to drought and privation.
Zel (Iranian Thin-Tailed)
Caspian region of northern Iran. Female 30-32 kg. Well adapted to subtropical regions, they produce coarse wool, milk, and excellent meat that lacks the "mutton taste" and odor of some sheep meats.
Mountain and island types. Female 30 kg; male 40 kg. These common sheep are active, hardy, and resistant to extremes of climate and disease. Primarily a milking sheep, their wool is used locally and lambs are slaughtered for special occasions.
Crete. Female 25 kg; male 30 kg. Another of the hardy, screwhorned "zackel" sheep common to the Balkans, they are adapted to poor pasturage and extensive herding. Quick maturing and highly fertile, they can be exploited for milk as well as for meat and coarse wool.
Female 25 kg; male 35 kg. Similar to the Greek Zackel, they are used as triple-purpose animals: meat, milk, and wool. They survive in low, marshy areas where parasites are common.
Yugoslavia. Female 25 kg; male 35 kg. A small, hardy sheep used for milk and some meat, its primary product is wool. Often unshorn for several years, the long fibers are woven into expensive carpets.
Yugoslavia. Female 20-30 kg; male 25-35 kg. These wool, milk, and meat sheep are frugal and well adapted to scant vegetation and rocky terrain. Although they have a low birth rate and carcass yield, their milk and wool are commercially exploitable.
Northern Italy, Austria. Female 30 kg; Male 30-35 kg. These "stone sheep" resemble a goat in their ability to exploit the poor pastures of high, steep, rocky mountains. Although not highly productive, they are hardy and frugal and commonly produce twins.
Corsica (France). 25-30 kg. A hardy native breed that is well adapted to rather sparse feed conditions. Coarse wool, both white and black, is well suited for hand processing.
Entre Douro e Minho
Portugal. Female 15-18 kg; Male 20-25 kg. These independent sheep yield a good wool in mountainous terrain that would otherwise be nonproductive.
Churra do Campo
Portugal. Female 20 kg; male 30 kg. A coarse-woofed sheep extensively kept in Portugal's dry interior for milk and wool.
Spain. Female 18 kg; male 25 kg. A milking breed that survives on poor pasture, it also produces a marketable wool.
Scotland. Female 25 kg; male 30 kg. Adapted to wide temperature variations. Possibly the most primitive domesticated sheep of Europe, probably unchanged from Viking times. Immune to foot rot. A wool sheep with short brown fleece that is shed annually.
North Ronaldsay (Orkney)
Northern Scotland. 27-32 kg. Surviving year-round on seaweed, this rare breed is adapted to high salt intake and the associated digestive problems. Yield 1-2 kg medium-coarse wool.
Latin America. Derived from ''native'' Spanish Churro and Merino sheep. Many are small and very hardy.
Navajo-Churro Southwestern United States. Female 45 kg; male 70 kg. Maternal, and very resistant to internal parasites and hoof rot. Although the Navajo subsists and reproduces on little feed and scarce water in desert regions, it was widely replaced by improved breeds earlier in this century. Because of its hardiness, however, and the use of its wool in traditional weaving, its numbers are rebounding (see sidebar, page 50).
Florida Native Southeastern United States. Females 35-45 kg; males 45-6O kg. This long-isolated and highly variable sheep is adapted to harsh subtropical climates and is known for its ability to forage. A medium-wool breed, it is very resistant to intestinal parasites. Verging on extinction due to neglect and uncontrolled crossbreeding.
Virgin Islands White Hair (St. Croix)
Caribbean. Female 35-45 kg; male 45-55 kg. Hair sheep with some wool in young animals. Well adapted to warm humid conditions, it has fairly good disease and parasite resistance and produces good meat. Prolific, it breeds most of the year and commonly has twins.
Northwest India, Pakistan.4 20-25 kg. Adapted to hot, dry areas, the extremely white and shiny fleece is valued for carpet wool. Slowmaturing and low fertility (lambing at 45 percent) plus extensive crossbreeding have led to serious declines in population.
Northwest India. 25-30 kg. A widespread, white-fleeced sheep that has a high resistance to disease and worms, good fertility, and low mortality. They do well in large flocks.
Southwest India. Female 25 kg; male 35 kg. An outstanding meat breed with good mutton quality, it adapts well to mixed farming and has unusually low lamb mortality.
Hu (Huyang, Lake Sheep)
China. Female 35 kg; male 45 kg. These fat-tailed sheep have a six month lambing interval and are very prolific. They are used under intensive management to produce meat, wool, and a valuable lambskin.
Indonesia. 25-40 kg. Widely held as a "bank account," these meat, manure, and skin sheep are well known for being prolific. Although single lambs are not uncommon, litters of six have also been recorded.
WILD AND WOOLLY
Considering that dozens of countries depend on the productivity of more than a billion domesticated sheep, it is remarkable that their wild ancestor is accorded no attention. This fast-declining animal is now little more than a trophy for hunters, a fact that should be of vital intemational concern.
Sheep were domesticated in the Middle East and Central Asia in the Stone Age era between 8,000 and 11,000 years ago.* Their wild ancestor was almost certainly the mouflon (Outs orientalis). However, domestication may have occurred in more than one place, and two other wild creatures, the urial (Outs vignei) and the argali (Outs ammon), also possibly provided genes to some sheep breeds.
The mouflon, urial, and argali still exist in the mountains of Central Asia, and a European subspecies of mouflon is also found in the Mediterranean, but only on Corsica, Cyprus, and Sardinia.** Because they live in remote, rugged, upland areas, these wild sheep are usually undisturbed, but the numbers are decreasing everywhere.
This may be a serious loss because these animals could be extremely valuable. They are capable of crossing with domestic sheep, and the offspring are viable and fully fertile.*** For developing new meat-producing breeds, their potential seems almost limitless.
During the thousands of years that sheep have been protected by humans, their wild ancestors have continued to face predators, parasites, disease, extreme cold and seasonal starvation. Their genetic endowment, forged and tempered in unforgiving harshness, could be a benefit for all future sheep generations. These animals appear to resist various diseases. Their meat is reported to be of excellent quality, notably lacking the strong mutton flavor that many people find objectionable. They have relatively short, thin tails - a feature that might eliminate the need for docking (tail removal) in the domestic flock. Some (for instance, the Asian mouflon and the urial) have rates of effective reproduction up to 1.6 lambs per ewe, more than twice the average of most domestic types, especially under the conditions where these wild creatures live.
That mouflon and other wild sheep could have practical utility is suggested by research at Utah State University. Scientists there have mated mouflon with farm sheep to create sheep better able to defend themselves against coyotes and other natural dangers. Half-wild, half-tame sheep hybrids have existed on a ranch in southern Utah for the past decade. Also, in Cyprus similar mouflon x sheep hybrids have shown considerable promise.
At the very least, this wiry little mountain sheep could be a model for educating students and the public. It is a living reminder of the fantastic changes that can be induced in animals by selection for various traits. Also, it is a "map" to the history of sheep domestication. Studies of mouflon genes, blood immunology, morphology, physiology, horn structure, skeleton, fleece, temperament, and a host of other features would help unravel the ancestry. These studies and various biochemical analyses would be a fascinating contribution to agriculture, science, history, and the public perception of the origins of our natural resources.
Genes from wild sheep are not likely to quickly benefit wool production. Lack of fleece is one reason why these creatures have been neglected but throughout most of Asia and in North Africa, sheep are bred primarily for meat and milk, and there is a growing worldwide interest in the use of hair sheep. All of this brings new possibilities for the use of this old resource.