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Chicks waiting for their first taste of freedom. |
Interest in poultry raising is steadily growing. Poultry products are in greater demand than ever. The obvious purpose of this lesson, however, is not directly to cover these points. It is rather to define the meaning of an egg, to learn of the parts comprising it, and from this information to deduct the proper meaning that the best results in the more practical operations of raising fowls for eggs and meat may be secured. The composition and nature of the egg must be fundamentally considered in order to attain the best success with laying flocks.
In most kinds of animals reproduction takes place by means of eggs. Mammals give birth to and suckle their young. Birds and many of the lower species produce eggs. Great variation exists as to the manner of reaching adult life. With some members of the animal kingdom many changes occur, the little creature on hatching being altogether different than at other stages of its existence. The life history of a butterfly or moth is a story quite different from that of a snake or fish, and that of a bird from that of a tadpole or lobster. In domestic poultry, on hatching from the egg, a baby bird is born, identical in every way with its subsequent enlargement. The egg is for the purpose of reproduction. It is the beginning and the end of the life cycle. Birds, according to their sex, produce eggs or contribute to their fertilization in order that their species may be perpetuated. Egg laying is not to provide a nutritious food for the breakfast table.
An ordinary good-sized hen's egg weighs about two ounces. The weight varies according to the breed, some eggs weighing 2 1/4 ounces and others 13/4 ounces or less. An egg consists of four parts - the outer covering or shell, the yolk or food supply of the chick at hatching, the white, or mass of albumen for developing the embryo, and the germ, or life substance. The white material comprises about 60 percent of the entire egg, the yolk about 30 percent and the shell about 10 percent.
The outer covering of an egg is sometimes brown and sometimes white, the color depending in a large measure on the breed or variety of the hen. Color is due to a pigment developed in the shell and is a fixed character of the breed. The shell is composed of carbonate of lime, phosphate of lime, and animal gluten. It is very porous. It has between the particles of lime an innumerable number of very small holes, which allow the air to pass freely backward and forward during the process of incubation. If it were not for these tiny holes the embryo within would die for want of oxygen to revive the impure blood that it produces.
Moisture is evaporated through these holes. The rapidity will depend on the conditions and the temperature under which the egg is kept. The air space at the broad end of the egg indicates the amount that has been evaporated. The longer an egg is kept the larger the air space becomes. This is one way to tell the age of an egg.
The white of an egg is a strong solution of albumen in water, and while readily mixable with water in its ordinary state, it becomes insoluble when subjected to heat. In 100 parts, the white consists of 80 of water, 15 1/2 of pure albumen, and 4 1/2 of salts and ash. It is formed in three layers, which can be plainly seen when a hard-boiled egg is cut in two.
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a, 18 hours, b, second day; c, 40 hours, d, third day; e, fourth day, f, fifth day; g, just before hatching; h, at peeping time; and i, nearly out of shell |
What is known as yolk is a strong solution of albumen, through which multitudes of globules of fat are suspended, the whole being enclosed in a sack that floats in the white. In 100 parts, water composes 53 3/4, albumen 17 1/2 and fat or oil 28 3/4 parts. The yolk is lighter than the white and therefore rises to the upper side whichever way the egg is turned. The yolk serves as food while the chick is developing inside the shell and for the first days after hatching. This explains why a chick recquires no food for a short period after it leaves its shell.
Next to the shell, and fastened to the yolk, the germ or true egg is to be found. It is known as the blastodeim, the minute nucleus of what is afterward to be the chick. This word means sprouting skin. The blastoderm is present whether the egg is fertile or not, so that it is impossible to tell beforehand whether an egg will produce a chick. A fertile and infertile egg to the naked eye are the same in appearance. The application of a few hours' warmth of the required temperature brings into activity all the power lying dormant from the time the egg was laid. After five or six hours, little finger-like processes begin to creep out from the blastoderm and gradually distribute themselves over the whole of the yolk.
Eggs raised for commercial purposes should not be fertilized, and they should be stored in a cool place during collection for shipment. Fertile eggs in the hot days of summer show signs of incubation very quickly. If roosters are kept away from the laying flock and a cool basement is chosen for the storage place, the eggs will remain fresh much longer and they can be shipped a longer distance.
A fertile egg incubates very rapidly if provided with the proper degree of heat. After only 18 hours the head of the future chick, with eyes enormously developed, and the spinal column, are plainly discernible under the microscope. After 40 hours there is a complete blood circulation, the heart is formed and beating commenced, and the blood vessels have spread over a considerable portion of the upper yolk. These are of a dual character; some are arteries, taking blood away from the embryo, some are veins bringing the blood back again. The heart commences pulsating about the second or third day. When blood circulation begins impure air is revived by the oxygen, obtained from the air that passes in and out of the holes of the shells. Were you to coat over with wax an incubating egg, the embryo would die from want of fresh air.
Eggs during incubation require cautious handling; otherwise the delicate blood vessels, which form a perfect maze of tracery over the yolk, may be disturbed or injured. The less that eggs are moved about, the less danger of damaging the fragile and delicate interior. Many dead embryos in the incubator are the result of careless turning and handling. In testing out a hatch to remove the infertile eggs, it is very important that the work be done with careful movements in order not to shake or twist the sensitive and delicate organs inside the egg.
In selecting eggs for hatching use only those of uniform size and color, with smooth, strong shells. Abnormal eggs are likely to produce weak or crippled chicks. The eggs should be stored in a room where the temperature ranges from 40 to 50 degrees. Eggs for hatching should be turned two or three times a week until the required number has been collected. Never set dirty eggs. If they are dirty, carefully wipe with a damp cloth until all spots are removed. Eggs are at their best, both as to fertility and vitality, when natural hatching is in season. Before this time fertility is poor and vitality excellent. In summer, more eggs are fertile, but the vitality of the chicks is lower than earlier in the year.
Hens kept mainly for producing eggs often annoy the poultryman by persistent broodiness. These should be culled out and never used for breeders. In otherwise normal hens broodiness may be broken when necessary. It is usually an advantage to allow the hens to hatch broods, since this gives them a rest from laying. Hens of the general purpose varieties usually lay better during the molt than hens of the noted egg-breeds. These egg layers generally take a long rest, the sitters two or three short ones.
To break up broodiness, a quick way is to confine the hens with a reserve male in a pen where there are no nests. While so confined, the hens should be fed well on an egg ration. Often the hens will begin to lay within a week or ten days. Under no condition should starving be practiced. It is not only cruel and ineffective, but the poultryman who practices it pays the penalty by injuring the laying proclivities of the hen.
Laying hens are nearly always singers. They work and hunt for food all day, and are the first off of the roost and the last to go to roost. They are nervous and very active, keeping themselves up to the greatest possible pitch. In selecting layers, seek out the active, hustling kind and reject those dull, lazy and inactive.
The ideal laying hen should conform as nearly as possible to the following. She must be healthy; comb, wattles and face red; eye bright and lustrous; neck not short, but medium to long; breast broad and long, sloping upward; back, long and broad; abdomen, wide and deeper than breast; shanks well spread and rather long; V-shaped in three ways - on sides from front to rear, top and bottom from front to rear, and from base of tail, downwards; and well spread tail.
Hens should be brought into laying as early as possible. When hens begin to lay in the fall, they are more likely to continue laying than if they are expected to start laying some months later. Many pullets which begin to lay in the fall are naturally poor layers and soon play out. The sooner such fowls are taken out of the flock the better. They should not be used for breeding. An important thing to remember in rearing fowls for winter laying is to have the pullets mature between September and November. This can be determined by the date of hatching and by the method of rearing.
So far as egg laying is concerned, the egg farmer's year begins in October. Everything should then be put in readiness for egg production. The pullets and hens should be placed in their permanent winter quarters and special care taken to prevent overcrowding. The sooner the flocks are made up, the better, as a rule, because they then get accustomed to their quarters, and there is less danger of upsetting them when they begin to lay. None but mature pullets should be selected for laying. All that are puny, undersized, lazy, weak or otherwise undesirable should be weeded out and sold for the table. They will not pay their board.
Only such hens as have proved their worthiness in the previous season, should be kept over for a second or third winter. They usually make good breeders and the breeding flock should be selected from them rather than from pullets. Too often, however, in the farm flock, the reverse practice is followed. The hens that are in best condition are sold; the inferior ones are kept for egg production.
It is just as important to feed well for eggs as it is to breed well for them. Contrary to popular opinion, hens that are molting should be fed well. It does not pay to stint molting hens. However, they should not get a ration too rich in nitrogenous matter, because they are not, as a rule, laying, and they do better when given a ration richer than usual in carbonaceous ingredients. Even if this is a fattening ration, it will do no harm. By this it is not meant that the nitrogenous matter should be cut out of the ration altogether. Feather production demands protein, which must not be fed too sparingly. It is preferable, as a general rule, to have fowls somewhat too fat than poor or even in merely good condition. By proper management many good laying hens will lay an occasional egg, even while going through molting, but this is not general.
Pullets can be fed more highly than hens during the early fall months, because they already have their feathers and are still growing. At this time, they need abundant protein, because they are not only growing in flesh, but are filling out their bones and either preparing for, or actually laying. A pullet is by no means fully matured when she starts to lay. Ample food is needed to complete the development. For best results, however, pullets should not be unduly forced to begin laying early. Indeed, it is often advantageous to delay laying somewhat by frequently changing the pullets' quarters. This is the only method that can be practiced with safety. It will not do to withhold food.
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