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By Wayne Smith
Copyright 2001
All our breeds and varieties of chickens have a common origin. Their ancestors were the Jungle Fowl of Southern Asia.
The Jungle Fowl were small birds, which laid one, or two clutches of eggs each year and foraged in the jungles for bugs and seeds. The large size and large laying capacity of our present breeds is due to selective breeding, good care, and abundant feed continued over a considerable number of years.
It is amazing what wonders can be achieved through careful selection of ones breeding stock. It is worth considering here that fowls as unlike as the massive Brahma, with feathered legs and feet, and the diminutive Game bantam, with sprightly disposition; the Minorca, with its ponderous comb, and the Polish, with only the rudiments of a comb and in its place a great ball of feathers, are all descended from the wild Jungle Fowl. Such a varied gene pool coming from such a limited number of types of birds causes me to wonder what genes we still have in to-days poultry.
Domestic poultry were first brought to North America by early explorers, chiefly Games from England, and the Dominique from Holland and France. These were bred without any attempt at uniformity, and consequently dwindled into small mongrel types. A little over a hundred years ago more attention started to be given to selective breeding. Once selective breeding started the development and refinement of poultry moved quite rapidly and continues even to day
In conjunction with the skilful breeders of England, Holland, France and other Western European countries, American and Canadian fanciers have produced and fixed the type of fowl that are both useful and beautiful. The making and perfecting of the various Standard varieties has had a distinct and marked effect in building up the economic side of poultry husbandry, for there is a close relationship between beauty, interest and function.
The Body Structure of a Chicken
The covering of feathers is the only characteristic belonging to the domestic hen and common to all bird life that is not found in other animal species. The principle use of the feathers is to protect the bird from extremes of heat and cold, but they also have value in incubation and for flying.
The body frame of a bird has the general character of that of other animals, although it varies in shape from that of non-flying animals. It also has numerous air cells in its body, which because they are connected directly with the lungs the bird can take in, hold or expel air from them at will.
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This enables the bird to make its body buoyant when it desires to fly. Its bones are also extremely light and are marrowless, as well as much harder and whiter than those of mammals. The hen has four limbs, two for walking and two for flying. The former are the legs (thighs, shanks and toes). The latter are the wings, corresponding to the hands and forearms of the human skeleton. With three exceptions all breeds of fowls have only four toes on each foot, Dorkings, Houdans and Faverolles having five.
The most highly developed bone in the fowl's body is the breastbone. Shaped somewhat like the keel of a ship it is used to support and protect the vital organs in the abdominal cavity just above it. To the breastbone, or keel, is attached the flight muscles, which vary in size to conform to the size of the wings. The most sought after flesh on a fowl grows on the breastbone.
The pelvic arch is the bony structure, which supports the upper part of the body, and the bones, which compose it, are usually referred to as the lay bones.
The Muscles And Organs
The working parts of the fowl's body, like those of the human are the muscular, digestive, circulatory, respiratory, reproductive and the nervous system.
The muscles not only furnish the means by which the bird can move about but also cover the bones and fill out the body contour. Their characteristic forms are largely inherited but are also influenced by feeding, environment and management.
The digestive organs differ considerably from those of mammals. The hen has no teeth therefore she requires small sharp-edged stones in her gizzard to grind the food. The other organs through which the food passes after being picked up by the beak are the gullet, the crop, the stomach, (where gastric juice is stored and mixed with the feed) The gizzard (where the food is ground) the intestines (where a major portion of digestion takes place) then the cloaca, from which it is voided.
The principles of the fowls circulatory and respiratory systems are the same as that of most animals, but the reproductive organs are radically different. The female chick is hatched with two ovaries, but only one develops, and this, with the oviduct, forms the reproductive system of the female. The reproductive system of the male includes two glands, called testis, which are located internally near where the last ribs join the backbone. They secrete sperm, which passes through tubes to the cloaca.
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