Fowl - biology.
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Fowl - biology.
I
INTRODUCTION
Fowl, term originally meaning any kind of bird, and later applied chiefly to edible species. Except in combinations such as waterfowl and wildfowl, in modern usage the
word usually is restricted to the common domestic fowl, or chicken. In poultry markets, fowl commonly means a full-grown female bird. Young birds of both sexes, such
as broilers and fryers, are called chickens. On poultry farms, male chickens are called roosters or cocks; females, especially those more than a year old, are called hens;
females less than a year old are called pullets; very young chickens of either sex are called chicks; and castrated males are called capons.
II
PHYSICAL CHARACTERISTICS
Like the turkey, pheasant, quail, and other related birds, the domestic fowl is adapted for living on the ground, where it finds its natural foods, consisting chiefly of
worms, insects, seeds, and greenstuff. The feet, usually four-toed except in the English breed, Dorking, are designed for scratching the earth. The large, heavy body
and short wings make most breeds incapable of flying except for short distances. The crop is large and the gizzard strongly muscular. In adults of both sexes the head
is decorated with wattles and a naked, fleshy crest, called the comb, which is more prominent in the male and is variously shaped in the different breeds and varieties.
The typical comb is single, serrated and relatively large, either erect or drooping. A variation is the rose comb, with three rows of tubercles merging in a rearwardpointing spike. The pea comb of the Brahma has three low serrated ridges, and the leaf comb of the French Houdan has two ridges, set transversely on the head. The
strawberry comb of the Malay fowl is a small, rounded, nodular protuberance set near the eyes, and the V-shaped comb of the La Flèche fowl suggests a pair of tiny
horns. Plumage of various fowl ranges in color through white, gray, yellow, blue, red, brown, and black.
In size and shape the various breeds show great diversity. The 5-kg (12-lb) Brahma cock, for example, has a miniature counterpart, the Bantam, weighing about 567 g
(about 20 oz). The proportions of the long-legged game fowl contrast sharply with those of the squat Cochin. The stubby tail of the latter is one extreme; another
extreme is presented by the Japanese or Yokohama breed, in which the tail feathers of the cock may be as much as 2 m (6 ft) long. In general the members of one
breed are alike in shape, the varieties of the breed differing in minor characteristics such as the shape of the comb and in color and markings. A group of breeds
developed in a single country or geographical area is often called a class.
In habit, chickens are strictly diurnal, highly gregarious, and polygamous; cocks of the game breeds are especially noted for their courage and pugnacity with rivals. The
high fecundity of the species is an important characteristic, especially because the eggs as well as the meat are prized as food (see Egg). Unless otherwise trained,
female chickens lay their eggs on the ground, in tall grass or weeds. Periodically, domestic hens become broody; that is, they stop laying and show a strong desire to sit
on their nests and hatch chicks. The incubation period is approximately three weeks. The chicks are precocial; that is, when hatched, they are not naked but covered
with down and are immediately able to run around. Although they are able to feed themselves, newly hatched chicks can survive about a week without eating,
subsisting on egg yolk that is included in the abdomen. Chickens may live as long as 15 years in captivity, depending on their breed and the quality of care they
receive.
III
ORIGINS
Domestic fowl probably originated in Southeast Asia. Charles Darwin considered them descendants of a single wild species, the red jungle fowl, which is found in the wild
state from India through southeast Asia to the Philippines. Genetic analyses have shown that every breed of domestic chicken can be traced to the red jungle fowl.
Scientists estimate that they were domesticated roughly 8000 years ago in what is now Thailand and Vietnam.
The chicken was one of the first domestic animals to be mentioned in recorded history. It is referred to in ancient Chinese documents that indicate that this "creature of
the west" was introduced into China about 1400
playwright Aristophanes about 400
BC.
BC.
Fowl are depicted in Babylonian carvings of about 600
BC
and are mentioned by early Greek writers, notably by the
The Romans considered chickens sacred to Mars, their god of war. Since ancient times the rooster has been a symbol of
courage--it was so regarded by the Gauls, for example. In Christian religious art the crowing cock has symbolized the resurrection of Christ. The cock was the emblem
of the first French Republic.
Today domestic fowl, which form by far the most important class of poultry, are distributed virtually all over the world. In the United States the current trend is toward
specialization, some poultry raisers producing hatching eggs, others eggs for table use, and others raising chickens to market as broilers. See Poultry Farming.
IV
BREEDING
Numerous breeds and several hundred varieties of fowl are now recognized; new varieties are in the making, moreover, as breeders strive to improve their stock for
particular purposes. The breeds may be classified according to the parts of the world in which they originated and also according to their function. One category is the
game fowl still bred in some areas for their fighting qualities (see Cockfighting). Elsewhere, game breeds are kept by fanciers for ornamental purposes and for exhibition
at poultry shows. The exhibition varieties of game fowl are characterized by long necks and shanks and sparse tail feathers. Other ornamental breeds are the Bantam;
the Japanese fowl; the Polish fowl, with its great crest of feathers; the downy-feathered Silky; and the ragged-looking Frizzle.
Among breeds of economic importance, the oldest class, originating in China in the remote past, is the Asian group, including the Brahma, Cochin, and Langshan. They
are large, heavy birds with thick, fluffy plumage and feathered shanks. Their meat is coarse in texture, and they are poor egg producers. They are hardy, however, and
thrive in cold climates. Asian stock has contributed greatly to the formation of the American breeds.
English fowl are distinguished for the fine quality of their meat and, like the French breeds, are more valuable as table birds than as egg layers. The Belgian Campines,
on the other hand, are small but prolific. The outstanding egg producers are the Mediterranean breeds, which include the Ancona, Andalusian, Minorca, and Leghorn,
the single-comb White Leghorn being the most popular variety. Except for the Minorcas, the Mediterranean fowl are small and therefore uneconomical as meat poultry,
but they consume relatively little feed. They are generally prolific, and their white eggs are large in proportion to their body size. The cost of egg production is lower,
therefore, and the profits often higher, than with other types of chickens. The pullets begin to lay early and have the advantage, from the commercial point of view, of
poorly developed maternal qualities; little laying time is lost in broodiness. Sensitive to environmental changes, these birds are healthiest and lay most eggs in mild
climates.
The American class consists of general-purpose breeds developed in the past century to serve as producers of both meat and eggs. American breeds are moderate or
large in size, with meat of good quality. They are very hardy and lay well in winter. Rhode Island Reds are often as prolific as single-comb White Leghorns. The maternal
instinct is strong in American fowl, but in some strains it has been minimized by selective breeding. Usually birds of this class mature later than Mediterranean fowl but
earlier than Asian fowl. An exception in this respect is the fast-growing New Hampshire breed, formerly much used for broilers and fryers. The breed has been crossed
with Cornish and white Plymouth Rock breeds to evolve faster-growing and more efficient meat producers. These new types often bear the names of the original
breeder and account for the millions of broilers, fryers, and roasters now produced. Other American breeds are the Wyandotte and Plymouth Rock, each with several
varieties, and the Dominique, Java, and Buckeye.
Scientific classification: Fowl belong to the order Galliformes. The common domestic fowl, or chicken, belongs to the family Phasianidae and is classified as Gallus
gallus.
See separate articles on the individual breeds mentioned above. See also Duck; Fowl Cholera; Goose; Guinea Fowl; Incubator; Turkey; Veterinary Medicine.
Microsoft ® Encarta ® 2009. © 1993-2008 Microsoft Corporation. All rights reserved.
Fowl - biology.
I
INTRODUCTION
Fowl, term originally meaning any kind of bird, and later applied chiefly to edible species. Except in combinations such as waterfowl and wildfowl, in modern usage the
word usually is restricted to the common domestic fowl, or chicken. In poultry markets, fowl commonly means a full-grown female bird. Young birds of both sexes, such
as broilers and fryers, are called chickens. On poultry farms, male chickens are called roosters or cocks; females, especially those more than a year old, are called hens;
females less than a year old are called pullets; very young chickens of either sex are called chicks; and castrated males are called capons.
II
PHYSICAL CHARACTERISTICS
Like the turkey, pheasant, quail, and other related birds, the domestic fowl is adapted for living on the ground, where it finds its natural foods, consisting chiefly of
worms, insects, seeds, and greenstuff. The feet, usually four-toed except in the English breed, Dorking, are designed for scratching the earth. The large, heavy body
and short wings make most breeds incapable of flying except for short distances. The crop is large and the gizzard strongly muscular. In adults of both sexes the head
is decorated with wattles and a naked, fleshy crest, called the comb, which is more prominent in the male and is variously shaped in the different breeds and varieties.
The typical comb is single, serrated and relatively large, either erect or drooping. A variation is the rose comb, with three rows of tubercles merging in a rearwardpointing spike. The pea comb of the Brahma has three low serrated ridges, and the leaf comb of the French Houdan has two ridges, set transversely on the head. The
strawberry comb of the Malay fowl is a small, rounded, nodular protuberance set near the eyes, and the V-shaped comb of the La Flèche fowl suggests a pair of tiny
horns. Plumage of various fowl ranges in color through white, gray, yellow, blue, red, brown, and black.
In size and shape the various breeds show great diversity. The 5-kg (12-lb) Brahma cock, for example, has a miniature counterpart, the Bantam, weighing about 567 g
(about 20 oz). The proportions of the long-legged game fowl contrast sharply with those of the squat Cochin. The stubby tail of the latter is one extreme; another
extreme is presented by the Japanese or Yokohama breed, in which the tail feathers of the cock may be as much as 2 m (6 ft) long. In general the members of one
breed are alike in shape, the varieties of the breed differing in minor characteristics such as the shape of the comb and in color and markings. A group of breeds
developed in a single country or geographical area is often called a class.
In habit, chickens are strictly diurnal, highly gregarious, and polygamous; cocks of the game breeds are especially noted for their courage and pugnacity with rivals. The
high fecundity of the species is an important characteristic, especially because the eggs as well as the meat are prized as food (see Egg). Unless otherwise trained,
female chickens lay their eggs on the ground, in tall grass or weeds. Periodically, domestic hens become broody; that is, they stop laying and show a strong desire to sit
on their nests and hatch chicks. The incubation period is approximately three weeks. The chicks are precocial; that is, when hatched, they are not naked but covered
with down and are immediately able to run around. Although they are able to feed themselves, newly hatched chicks can survive about a week without eating,
subsisting on egg yolk that is included in the abdomen. Chickens may live as long as 15 years in captivity, depending on their breed and the quality of care they
receive.
III
ORIGINS
Domestic fowl probably originated in Southeast Asia. Charles Darwin considered them descendants of a single wild species, the red jungle fowl, which is found in the wild
state from India through southeast Asia to the Philippines. Genetic analyses have shown that every breed of domestic chicken can be traced to the red jungle fowl.
Scientists estimate that they were domesticated roughly 8000 years ago in what is now Thailand and Vietnam.
The chicken was one of the first domestic animals to be mentioned in recorded history. It is referred to in ancient Chinese documents that indicate that this "creature of
the west" was introduced into China about 1400
playwright Aristophanes about 400
BC.
BC.
Fowl are depicted in Babylonian carvings of about 600
BC
and are mentioned by early Greek writers, notably by the
The Romans considered chickens sacred to Mars, their god of war. Since ancient times the rooster has been a symbol of
courage--it was so regarded by the Gauls, for example. In Christian religious art the crowing cock has symbolized the resurrection of Christ. The cock was the emblem
of the first French Republic.
Today domestic fowl, which form by far the most important class of poultry, are distributed virtually all over the world. In the United States the current trend is toward
specialization, some poultry raisers producing hatching eggs, others eggs for table use, and others raising chickens to market as broilers. See Poultry Farming.
IV
BREEDING
Numerous breeds and several hundred varieties of fowl are now recognized; new varieties are in the making, moreover, as breeders strive to improve their stock for
particular purposes. The breeds may be classified according to the parts of the world in which they originated and also according to their function. One category is the
game fowl still bred in some areas for their fighting qualities (see Cockfighting). Elsewhere, game breeds are kept by fanciers for ornamental purposes and for exhibition
at poultry shows. The exhibition varieties of game fowl are characterized by long necks and shanks and sparse tail feathers. Other ornamental breeds are the Bantam;
the Japanese fowl; the Polish fowl, with its great crest of feathers; the downy-feathered Silky; and the ragged-looking Frizzle.
Among breeds of economic importance, the oldest class, originating in China in the remote past, is the Asian group, including the Brahma, Cochin, and Langshan. They
are large, heavy birds with thick, fluffy plumage and feathered shanks. Their meat is coarse in texture, and they are poor egg producers. They are hardy, however, and
thrive in cold climates. Asian stock has contributed greatly to the formation of the American breeds.
English fowl are distinguished for the fine quality of their meat and, like the French breeds, are more valuable as table birds than as egg layers. The Belgian Campines,
on the other hand, are small but prolific. The outstanding egg producers are the Mediterranean breeds, which include the Ancona, Andalusian, Minorca, and Leghorn,
the single-comb White Leghorn being the most popular variety. Except for the Minorcas, the Mediterranean fowl are small and therefore uneconomical as meat poultry,
but they consume relatively little feed. They are generally prolific, and their white eggs are large in proportion to their body size. The cost of egg production is lower,
therefore, and the profits often higher, than with other types of chickens. The pullets begin to lay early and have the advantage, from the commercial point of view, of
poorly developed maternal qualities; little laying time is lost in broodiness. Sensitive to environmental changes, these birds are healthiest and lay most eggs in mild
climates.
The American class consists of general-purpose breeds developed in the past century to serve as producers of both meat and eggs. American breeds are moderate or
large in size, with meat of good quality. They are very hardy and lay well in winter. Rhode Island Reds are often as prolific as single-comb White Leghorns. The maternal
instinct is strong in American fowl, but in some strains it has been minimized by selective breeding. Usually birds of this class mature later than Mediterranean fowl but
earlier than Asian fowl. An exception in this respect is the fast-growing New Hampshire breed, formerly much used for broilers and fryers. The breed has been crossed
with Cornish and white Plymouth Rock breeds to evolve faster-growing and more efficient meat producers. These new types often bear the names of the original
breeder and account for the millions of broilers, fryers, and roasters now produced. Other American breeds are the Wyandotte and Plymouth Rock, each with several
varieties, and the Dominique, Java, and Buckeye.
Scientific classification: Fowl belong to the order Galliformes. The common domestic fowl, or chicken, belongs to the family Phasianidae and is classified as Gallus
gallus.
See separate articles on the individual breeds mentioned above. See also Duck; Fowl Cholera; Goose; Guinea Fowl; Incubator; Turkey; Veterinary Medicine.
Microsoft ® Encarta ® 2009. © 1993-2008 Microsoft Corporation. All rights reserved.
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