|
Items in cart [0] |
Questions? Call 888-624-8373 |
| Copyright © 2009. National Academy of Sciences. All rights reserved. Terms of Use and Privacy Statement |
Below are the first 10 and last 10 pages of uncorrected machine-read text (when available) of this chapter, followed by the top 30 algorithmically extracted key phrases from the chapter as a whole.
Intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text on the opening pages of each chapter.
Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.
Do not use for reproduction, copying, pasting, or reading; exclusively for search engines.
OCR for page 47
3
Microsheep
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
especially 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 predom-
inant 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.
47
OCR for page 48
48
AREA OF POTENTIAL USE
Worldwide, but notably in drier regions of the tropics.
APPEARANCE AND SIZE
MICROLIVESTOCK
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.
DISTRIBUTION
More than one billion sheep occur worldwide, and they occupy
every climatic zone in which people live. At least half are in developing
countries.
STATUS
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.
~ The largest, such as the New Lincoln breed of New Zealand, may weigh up to
250 kg.
OCR for page 49
MICROSHEEP
49
Ecuador: In the Andes, as in many parts of the Third World, small sheep are a common
resource. (E.G. Huffman, World Bank Photo)
BIOLOGY
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 manage-
ment, may produce lambs annually for more than five years.
BEHAVIOR
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.
OCR for page 50
se
MICROLIVESTOCK
THE LITTLE SHEEP THAT COULD
Dozens of the world's neglected breeds of tiny sheep should
bepreservedirom extinction, for many will undoubtedly prove
to have outstanding qualities. Current efforts to save the IYavajo
sheep in the United States exemplify what can be achieved
The IYavajo 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 IYavajos 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.
IYavajo 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 fIavajo sheep was reduced sharply between
1930 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 McIYeal, a Utah State
University professor, has been working to save it from extinc-
tion. 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 sup-
plementary food and with little water. As McIYeal 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.
Lie 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.
OCR for page 51
Ogden, Utah. Lyle McNeal and the Navajo sheep. (Lynn R. Johnson,
Salt Lake City Tribune)
Thanks to the efforts of MclYeal 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.
-
OCR for page 52
52
USES
MICROLIVESTOCK
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.
HUSBANDRY
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.
ADVANTAGES
Sheep are multipurpose animals, and almost everywhere they pro-
duce 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 transpor
OCR for page 53
MICROSHEEP
53
ration 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.
LIMITATIONS
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. As-
sessments should be made for the animals' ability to thrive under
adverse conditions and for resistance to particular diseases and para-
sites.
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
2 The small Soay sheep, for instance, is used in Cornwall, England, to graze banks of
highly erodible china-clay spoil too unstable to carry heavier animals.
OCR for page 54
~4
~ICROLIVES1OCK
~c sneer 1~ '"~ ~~=
~- _ ~ ~- ~ s--
= at ~o~f~ far =- s~t -~ =- a.
e ~Z~~ ~ an MAZY
Sewing war methods far stopping bash Tom smothedng
newly planted Deed U.S. adornment wasters hoe tamed
Tom chemlml deplane to 00c~ of sheep. Court decathlons
in lDS5 and flags' baaed the use of herb~ldes gong Oregon
Marc CoasL Idol alternates were Plea and the animals
proved the most successful. Sheep are nag the gored method
for ~n~lllog ad Ton. laded ~ ~ chard
me ~resters' Mole approach ~ managing =~res~tlon.
Overly the U.S. wrest Seance aged the bash ~ ~
~ logged-~r shes and then spied it dam before planing
we seedings. Ma ~ plank glass to suppress bash and
reduce erosion. The sues are later Laze gee seedllogs are
planted, and Than a year sheep are brought in to graze.
Age Oregon. ^ Mock of sheep suppressing bash that would otherwise
smother young Or trees. (gem LO ~~ ~= Futures)
OCR for page 55
MICROSHEEP
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, COO sheep have been guided
across the replanted areas by a herder and a range conser-
vationist. 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 Freckle, 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
$13~$353 per hectare. flow, 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 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.
55
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.
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
3 Wilson et al., 1989.
OCR for page 56
56
Berber
MICROLIVESTOCK
Atlas Mountains. 25~1 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.
Arab
North Africa. 4~50 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.
Hejazi
Deserts of Arabia. 32 kg. A popular and ancient fat-tailed meat
producer that is highly acclimatized to drought and privation.
Ze! (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.
Greek Zacke!
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.
OCR for page 57
MICROSHEEP
Sitia
57
Crete. Female 25 kg; male 30 kg. Another of the hardy, screw-
horned "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.
Common Albanian
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.
Zeta Yellow
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.
Pag
Yugoslavia. Female 2~30 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.
Roccia (Steinschaf)
Northern Italy, Austria. Female 30 kg; Male 3~35 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.
Corsican
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.
OCR for page 58
~8
MICRO LIVE SlOC K
-~n an Bock
Car ~' ~ ~ ~s domed on ~e p
duff ~ got ~n a faze -~-fed she~ if
off ~ ~~ arm ~ AL ~ arm.
~ ~~- If ~ "~ I~e ~ ~n a ~- Car
h~ a ~ If ~ be ~ Oaf ~' Inns
Sheep were domesU=ted in the Middy Last and Central gala
~ the Stone Age em between FOOD and 11,000 years agog
Thea ~ ancestor Is almost comply the mouOon (Oak
of Downer domesU=t~n ma ha occurred in more
than one pack and go other gild creatures the udal (Oaf
GINO and the arms (Oaf a~~ont also posslb~ provided
genes to some sheep breeds.
The mouOon, urial, and Shrill still Flat in the mounters of
Central ask, and a European subspecies of mouOon ~ also
fund ~ the MedRe~n~ but only on Corms -~ and
Sardlnla. * * Bemuse they lee in remote, rugged, upland army
these wild sheep are usually undlsturbe~ but the numbers are
decrying eve~hem.
This may be a sedous loss bemuse these animals could be
Obesely valuable. They are capable of crossing with domestic
sheep, and the gaping am gable and hilly ~11~*** For
d~eloplog new m~t-p~duclng breeds they potent/al seems
almost llmltless.
Durlog the thousands of years that sheep hoe been protected
by humane their wild ancestors have continued to lace pred-
ators, pamslte~ dls~se, extreme cold, and seasonal s~-
Hon. Thea geneUc endowment barged and tampered in un-
~rgl~ng harshness could be a benefit tar an Stud sheep
gene~tlons. These animals appear to resist Parlous diseases.
Thea meat ~ reposed to be of placement qualm no~bly Icing
the strong mutton Oavor that many people and o~ecUonabl~
They hoe relatively show thin ~ Mature that might
almanac the need tar docking (~D Camel) ~ the domestic
Dock. Some (par Sync the Asian mouOon and the udaD
hoe rates of e~cOve reproduction up to LO lambs per ~
more than Ice the avenge of most domestic ~es, aspect
under the condlbons where these wild creatures live.
That mouOon and other wild sheep could have p~cO=1
utHl~ is suggested by research at Utah Sate Unlversl~. Sck
enlists there hoe mated mouOon with ~ sheep to create
sheep better able to depend themselves ablest coyotes and
other natural dangers. Mall, halftime sheep hybrids have
Exited on a much in southern Utah bar the past decade. ^180,
OCR for page 59
MICROSHEEP
in Cyprus similar mouflon x sheep hybrids have shown con-
siderable 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.
59
* The first evidence for a domesticated sheep comes from 11,000-year-old
remains discovered at Zaw' Chemi Shanidar in Iraq. Almost certainly, it
happened when mouflons were attracted to the lush crops in fanners' fields.
** The specimens on these islands are probably feral domesticates, but they
seem little different from truly wild mouflon. They are probably relics of the
first domestic sheep taken to Europe by Neolithic fanners sometime between
6,000 and 7,000 B.C. On Corsica and Sardinia they escaped and have lived
wild ever since.
Another relic is the Sony (see page 60), found on islands in the Outer
Hebrides of Scotland. They, too, are primitive, but their fleece proves them to
be rather more domesticated than the mouflon.
* * * Mouflon is the only wild sheep with the same chromosome number as domestic
sheep (2n=54). The urial (2n=58) and the argali (2n=56) have different
chromosome numbers, but nevertheless, both will hybridize with domestic
sheep, and the offspring are also fertile.
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 exten-
sively kept in Portugal's dry interior for milk and wool.
OCR for page 60
60
Galician
MICROLIVESTOCK
Spain. Female 18 kg; male 25 kg. A milking breed that survives on
poor pasture, it also produces a marketable wool.
Soay
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.
Criollo
Latin America. Derived from "native" Span
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 501.
Florida Native Southeastern United States. Females 35-45 kg;
males 45~0 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.
ish Churro and Merino
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
OCR for page 61
MICROSHEEP
61
has fairly good disease and parasite resistance and produces good
meat. Prolific, it breeds most of the year and commonly has twins.
Magra (ChokhIa)
Northwest India, Pakistan.4 2~25 kg. Adapted to hot, dry areas,
the extremely white and shiny fleece is valued for carpet wool. Slow-
matur~ng and low fertility (lambing at 45 percent) plus extensive cross-
breeding have led to serious declines in population.
Marwari
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.
Mandya (Bandur)
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.
Javanese Thin-Tai!
Indonesia. 25~0 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.
4 South Asia has many fascinating breeds of microsheep. India has the Balangir (Orissa),
Chotanagpuri (Bihar and West Bengal), Coimbatore (Tamil Nadu), Ganjam (Orissa),
Hassan (Karnataka), Kilakarasal (Tamil Nadu), Madras Red (Tamil Nadu), Malpura
(Rajasthan), Mecheri (Tamil Nadu), Nali (Haryana), Ramnad White (Tamil Nadu),
Sonadi (Rajasthan and Gujerat), and Tiruchy Black (Tamil Nadu). Pakistan has the
Baltistan (Baltistan), Buchi (Punjab), Kooka (Sind), and Kaghani, Michni, Tirahi, and
Waziri (all North-West Frontier) Females of all these breeds weigh less than 25 kg at
maturity.
OCR for page 62
red
,/~-
~; /
: ~/ /
/ ~
ifs\
i
At:
AL
I t~ !
\
! ~
7 '/
//;
. . ~
{'at;
!
Representative terms from entire chapter:
domestic sheep
