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OCR for page 79
5
Chicken
Chickens (Gallus gallus or Gallus domestics are [D
the world's major source of eggs and are a meat source t'
that supports a food industry in virtually every country.
There may be as many as 6.5 billion chickens, the
equivalent of 1.4 birds for every person on earth.2 ' ~
No other domesticated animal has enjoyed such universal accept-
ance, and these birds are the prime example of the importance of
microlivestock. Kept throughout the Third World, they are one of the
least expensive and most efficient producers of animal protein.
To the world's poor, chickens are probably the most nutritionally
important livestock species. For instance, in Mauritius and Nigeria
more than 70 percent of rural households keep scavenger chickens. In
Swaziland, more than 95 percent of rural households own chickens,
most of them scavengers. In Thailand, where commercial poultry
production is highly developed, 8~90 percent of rural households still
keep chickens in backyards and under houses. And in other developing
countries from Pakistan to Peru, a similar situation prevails.
Clearly, these chickens should be given far more attention. They
represent an animal and a production system with remarkable qualities;
they compete little with humans for food; they produce meat at low
cost; and they provide a critical nutritional resource.
Scavenger chickens are usually self-reliant, hardy birds capable of
withstanding the abuses of harsh climate, minimal management, and
' Chickens were domesticated from one or more species of Southeast Asian junglefowl.
The actual number is unclear. Taxonomists accepting evidence for descent exclusively
from the red junglefowl refer to the domestic form as Gallus Callus, and those believing
in a descent from this and other species refer to it as Gallus domesticus. See sidebar,
page 86.
2 FAO, 1982, 1981 FAO Production Yearbook, Food and Agriculture Organization of
the United Nations, Rome.
79
OCR for page 80
For most parts of the Third World, scavenger chickens are a vital part of human
existence. (Periscoop)
inadequate nutrition. They live largely on weed seeds, insects, and
feeds that would otherwise go to waste.
Unfortunately, however, quantitative information about the back-
yard chicken is hard to obtain. Few countries have any knowledge of
its actual contribution to the well-being and diet of their people.
Notably lacking is an understanding of the factors limiting egg pro-
duction, which is markedly low and perhaps could be raised dramati-
cally with modest effort.
AREA OF POTENTIAL USE
Worldwide.
APPEARANCE AND SIZE
Chickens are so well known and ubiquitous that they need no further
description. Varying in color from white through many shades of
brown to black, they range in size from small bantams of less than
OCR for page 81
CHICKEN
81
red jungle fowl
grey
La Fayette's
red and green
at:
J
O ~!
Distribution of the red junglefowl, wild ancestor of the chicken, and its related species.
Junglefowls were domesticated in Southeast Asia in prehistoric times. Their domestic
descendants had reached the Indus valley by about 2500 B.C. and China by about 1400
B.C. They spread into Central Europe, probably also around 1400 B.C. As it spread,
the bird became transformed. For instance, although red junglefowls lay only one egg
every two or three months, some modern domestic hens lay eggs daily throughout most
of the year.
i kg to giant breeds weighing 5 kg or more. Scavenger chickens tend
to weigh about 1 kg.
The indigenous chickens of Asia are probably descended directly
from the wild junglefowl. Those of West Africa are believed descended
from European birds brought by the Portuguese in the sixteenth
century; those of Latin America probably descend from Spanish birds
introduced soon after the time of Columbus.
DISTRIBUTION
All countries have chickens in large numbers.
STATUS
They are not endangered, but industrial stocks are replacing tradi-
tional breeds to such an extent that much potentially valuable genetic
heritage is disappearing.
OCR for page 82
82
HABITAT AND ENVIRONMENT
MICROLIVESTOCK
Although chickens derive from tropical species, they adapt to a wide
variety of environments. The modern Leghorn, for example, is found
from the hot plains of India to the frozen tundra of Siberia, and from
sea level to altitudes above 4,000 m in the Andes. (There are, however,
hatching problems at such high altitudes because of oxygen deficiency.)
They also occur in desert countries such as Saudi Arabia, which has
a vast poultry industry and even exports broilers. (However, the birds
need shade and a lot of water where it is hot and dry.)
BIOLOGY
Chickens are omnivorous, living on seeds, insects, worms, leaves,
green grass, and kitchen scraps.
A commercial bird may produce 280 eggs annually, but a scavenger
may produce close to none. Commonly, a farmyard hen lays a dozen
eggs, takes three weeks to hatch out a brood of chicks, stays with the
chicks six weeks or more, and only then starts laying again.
Egg production depends on daylength. For the highest production
rate, at least 12 hours of daylight are needed. The incubation period
is 21 days. A hen can begin laying at 5 months of age or even earlier,
but in scavengers it may be much later. The average weight of the
eggs is approximately 55 g from industrial layers and approximately
40 g from scavengers. Hatching success from breeder flocks often
exceeds 90 percent. Industrial broilers can be marketed as early as 6
weeks, when they are called "Cornish hens."
BEHAVIOR
These passive, gregarious birds have a pronounced social (pecking)
order. If acclimated, they remain on the premises and are unlikely to
go feral. If given a little evening meal of "scratch," they learn to come
home to roost at night.
USES
Chickens have multiple uses. They were probably first used for cock
fighting; later they were used in religious rituals, and only much later
were raised for eggs and meat. Today, chickens can provide a family
with eggs, meat, feathers, and sometimes cash.
OCR for page 83
CHICKEN
HUSBANDRY
83
In different parts of the world, people keep scavenging chickens in
different ways. The managers are often women and children because
they have more time to spend at home to feed the birds and repel
predators. Some people leave the birds entirely to their own devices.
Many house them at night. Others take the birds each day to the fields,
where they may find much more food.
There are many ingenious local practices. In Ghana, for example,
farmers "culture" termites for poultry by placing a moist piece of cow
dung (under a tin) over a known termite nest. The termites burrow
into the dung, and some can then be fed to the chickens each day.
Because termites digest cellulose, this system converts waste vegeta-
tion into meat.
A ratio of 1 male to 1~15 females is adequate for barnyard flocks.
Hens will lay eggs in the absence of a rooster-but of course the
rooster is needed if fertile eggs are wanted.
Removing chicks stimulates the hen to lay more eggs. This results
in more chicks being hatched, but it requires that the chicks be nurtured
and fed until they are old enough to fend for themselves.
ADVANTAGES
Chickens are everywhere; every culture knows them and how to
husband them. They have been utilized for so many centuries that in
most societies their use is ingrained. Unlike the case with pork and
beef, there are few strictures against eating chicken meat or eggs.
The meat is high in quality protein, low in fat, and easily prepared.
In many countries, the village chicken's meat is preferred to that of
commercial broilers because it has better texture and stronger Havor.
Even in countries with vast poultry industries there is a growing
demand for the tasty, "organically grown," free-ranging chicken.
Chickens are more suited to "urban farming" than most types of
livestock and can be raised in many city situations.
The birds are conveniently sized, easily transported alive, and, by
and large, do not transmit diseases to humans.
LIMITATIONS
Throughout Asia, Africa, and Latin America, the problems of village
chickens are mainly those discussed below.
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84
High Hatching Mortality
MICROLIVESTOCK
Commonly, a hatch of eight or nine village chicks results in only
two or three live birds after a few days. A survey in Nigeria, for
instance, showed that 80 percent died before the age of eight weeks.
Losses elsewhere are known to be similar. This is mostly because of
starvation, cold, dehydration, predators (hawks, kites, snakes, dogs,
and cats, for example), diseases, parasites, accidents, and simply
getting lost-all of which can be prevented without great effort.
Chronic and Acute Disease
Poultry diseases can become epidemic in the villages because there
are few if any veterinarians. Newcastle disease, fowlpox, pullorum
disease, and coccidiosis, for example all of which are endemic in the
Third World can destroy the entire chicken population over large
areas. Lice and other parasites are also prevalent. Scavengers and
industrial birds seem to show no differences in their tolerance for such
diseases and parasites.
Low Egg Production
A survey in Nigeria showed that the annual production per hen was
merely 20 eggs. Such low production is common throughout the Third
World and is caused by a combination of low genetic potential,
inadequate nutrition, and poor management. Villagers rarely provide
nest boxes or laying areas, so that some eggs are just not found. Some
birds have high levels of broodiness, and eggs accumulating in a nest
stimulates this. There are indications, however, that some village
chickens (for example, some in China) have quite substantial egg-
laying potential when provided with adequate feed.3
Low Egg Consumption
In the tropics, many people choose not to eat eggs. Often this is
because eggs are the source of the next generation of chickens;
sometimes it is because of superstition. Further, eggs do not keep well
because most are fertile and, exposed to constant tropical heat, undergo
rapid embryo development.
3 Information from R.W. Phillips.
OCR for page 85
CHICKEN
Crop Damage
85
It is often necessary to confine the birds to protect young crops or
vegetable gardens.
RESEARCH AND CONSERVATION NEEDS
Unlike the situation with small cattle, goats, sheep, and pigs, there
are few named and recognized breeds of Third World chickens. Yet,
nearly every country has at least one kind of village chicken. These
have survived there for centuries and are highly adapted to local
conditions. In village projects, these unnamed chickens deserve priority
attention before other types are sought from elsewhere.
Generally speaking, improving the production of scavenging poultry
does not require sophisticated research. Instead, simple precautions
are sufficient. These are discussed below.
Disease Control
At a national or regional level, the initial approach to increasing
chicken production in tropical areas should be disease control. There
are several outstanding instances of success in this endeavor. For
example, the spectacular rise of poultry production in Singapore (from
250,000 birds in 1949 to 20 million in 1957) followed the control of
Ranikhet disease. Village flock-health programs, carried out regularly
by visiting veterinarians ("barefoot veterinarians"), might be the
answer to some of the routine health problems. Today, a prime target
should be Newcastle disease, for which there are good chances for
success (see page 761.
Management
The first step in chicken production at the farm level is improved
management. With more care and attention, mortality can be greatly
reduced. Because incubating and brooding hens must spend the night
on the ground, they are extremely vulnerable. Even modest predator
controls can be highly beneficial. Building crude and inexpensive nest
boxes and constructing a simple holding area around them can sub-
stantially raise production by ensuring that more chicks survive.
OCR for page 86
86
MICROLIVESTOCK
THE CHICKENS GILD ANCESTOR
Although little known to most people, the redjunglefowl has
contributed more to every nation than any other wild bird. It
is the ancestor of the chicken.
Given its descendant's importance worldwide, the neglect of
this bird is baffling. If the cow's wild ancestor, the aurochs,
had not become extinct in the 1600s, it would now be worth
millions of dollars as the ultimate source of cattle genetic
diversity. Yet the world's chicken industry remains virtually
unaware of the origin of its source of livelihood.
Like the aurochs, the red junglefowl has a wealth of wild
genes, and it deserves more recognition and protection. For
one thing, the modern chicken selectively bred in the tem-
perate zone is highly susceptible to heat and humidity; the
junglefowl, on the other hand, is not. It inhabits the warmest
and most humid parts of Asia: Sri Lanka, India, Burma,
Thailand, and most of Southeast Asia. It may also be resistant
to various chicken diseases and pests.
This is not a rare species. Throughout the wide crescent
stretching from Pakistan to Indonesia, junglefowls are still
seen in the wild, especially in forest clearings and lowland
scrub. Although they are a prized bag for hunters, they survive
by fast running and agile flying. They are sometimes sold in
village markets, but can easily be mistaken for domesticated
chickens, which in this region are often very similar. The wild
junglefowl, however, has feathered legs, a down-curving tail,
and an overall scragginess.
Junglefowls should be under intensive study. They are easy
to rear in captivity and do well in pens, even small ones, as
long as they are sheltered from rain and wind. One drawback
is their craze for scratching unless provided plenty of space
they promptly tear up all grass and dirt. Another is that
junglecocks are violent fighters and must be kept apart.
(Cockfighting is probably a major reason why they were initially
selected, and thus their aggressiveness is perhaps the reason
we have the chicken today.)
These highly adaptable creatures live in a variety of habitats,
from sea level to 2,000 m. Most, however, are found in and
around damp forests, secondary growth, dry scrub, bamboo
groves, and small woods near farms and villages. They are
amazingly clever at evading capture and thrive wherever there
iS some cover.
Other junglefowl species might also provide useful poultry.
They, too, can be raised in captivity with comparative ease, as
long as the cocks are kept apart. Perhaps they might be tamed
OCR for page 87
j ~ :~
:::: ~
: ~ :
:
Red junglefowl. (Monte Costa/Waimea Falls Park)
with imprinting and could prove useful as domestic fowl,
especially in marginal habitats. They are everywhere considered
culinary luxuries and their meat commands premium prices.
Moreover, several have colorful feathers, giving them additional
commercial value. These other species are:
· La Fayette's Junglefowl (Gallus lafayettei). A very attractive
bird of Sri Lanka, it is little known in captivity, and only in the
United States are there any number in captivity.
· Gray or Sonnerat's Junglefowl (Gallus sonnerati). A native
of India, this colorful bird produces feathers that are used in
tying the most prized trout and salmon flies. Demand is so
great that certain populations have declined, and since 1968
India has banned all export of birds or feathers. Nonetheless,
there are several hundred in captivity in various countries.
· Green Junglefowl (Gallus varies). This is yet another skik-
ing bird. The cock has metallic, greenish-black feathering set
off by a comb that merges from brilliant green at the base to
bright purple and red at the top. I`Iative to Java, Bali, and the
neighboring Indonesian islands as far out as Timor, it is found
particularly near rice paddies and rocky coasts. This species,
too, can be raised without great difficulty, and there are at
least 90 in captivity in various parts of the world.
At..
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88
MICROLIVESTOCK
THE SOUTH AMERICAIY CHICKEI`I
Early European explorers of South America were surprised
to discover an abundance of unusual chickens that laid colored
eggs and had feathers resembling earrings on the side of the
head. While the origin of this bird-commonly called the
araucanian chicken and classified as Gallus inaur~is debat-
able, scientists generally agree that it is pre-Columbian. There
is archeological evidence that this bird is native to the Americas.
It is reported to have occurred in Chile, Ecuador, Bolivia, Costa
Rica, Peru, and Easter Island. It still occurs in the wild in
southern Chile and on Easter Island.
The araucanian has been called the "Easter-egg chicken"
because it lays light green, light blue, and olive colored eggs.
It lays well and has a delicious meat. In areas such as southern
Chile the eggs are preferred over those of normal chickens
because of their flavor and dark yellow yolk. This unusual bird
has a high degree of variability; however, specimens of similar
genetic background have been grouped to create "breeds"
such as the White Araucanian, Black Araucanian, and Barred
Araucanian. These are homozygotes and breed true.
The araucanian has been the subject of much public interest;
clubs dedicated to its preservation have been formed in the
United States, Great Britain, and Chile. Its possible exploitation
as a backyard microlivestock deserves serious consideration.
OCR for page 89
CHICKEN
Nutrition
89
Improving poultry nutrition is also of prime importance. There are
no quantitative data on the quality of a scavenging chicken's diet.
Surveys are badly needed so that appropriate, low-cost supplements
can be devised.
Chances are that the diet for chicks of scavenging poultry is almost
always deficient in available energy. Minimal supplementation in the
form of cereals or energy-rich by-products can greatly improve both
egg and meat production. However, caution must always be exercised
and the supplements given only to chicks. Overfed adults will give up
scavenging and stay around the owner's house, without really producing
much more meat or eggs.
Genetic Improvement
Although it seems attractive to replace the scrawny village chicken
with bigger, faster-growing imported breeds, it is a process fraught
with difficulty. Exotic breeds lack the ability to tolerate the rigors of
mismanagement and environmental stress. Many cannot avoid pred-
ators, as a result either of being overweight or of having a poor
conformation for flight. The local birds, however, probably have a
genetic potential that is much higher than can be expressed in the
constraining environment. Thus, the environmental constraints should
be tackled first.
However, the village birds may have a feed-conversion efficiency
that is far less than ideal because they are adapted to a scavenging
existence. Modern breeds imported into Ghana, for instance, showed
a feed-conversion efficiency of less that 3.5:1 (weight of food eaten:
growth and eggs), but the local birds had efficiencies of 11:1.4
Conservation
The need for preserving genetic variability is greater in poultry,
especially in chickens, than in any other form of domestic animal.
North America, for instance, which years ago had 50 or more common
breeds, now relies on only 2 for meat production, and the others have
been largely lost. Conservation of germplasm has become a matter of
serious concern, and the saving of rare breeds in domestic fowl should
not be delayed.
4 If there is a good carbohydrate source (such as corn), the protein conversion is
excellent when this is combined with palm-kernel cake, peanut cake, or other sources
of protein that people cannot eat. More high-quality protein is obtained than is in the
corn. Information from M.G.C.McD. Dow.
OCR for page 90
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Representative terms from entire chapter:
red junglefowl
