After placing the eggs in the machine - which, by the way, should be operated at a temperature of 1030 in warm weather and 104o in the colder seasons - they should be left undisturbed for twenty-four hours. Then the drawer should be taken out and its contents given an airing for from five to ten minutes, according to the temperature of the incubator-room. Each egg should then be turned to bring its lower part to the surface, after which the drawer should be replaced in the machine. After this preliminary work, the drawer should be taken out both night and morning - in the first instance to air and turn the eggs, and in the second to simply turn them and replace them in the machine. Roughly speaking, the length of time the eggs should be allowed to air varies from five to ten minutes during the first week of incubating, from ten to fifteen during the second, and from fifteen to twenty minutes during the third. A good guide to follow when airing the eggs is the condition of the latter as they cool down. When they fall in temperature to lukewarm they should be replaced in the machine.
On the seventh day of incubation it will be necessary to test the eggs by means of a lamp specially made for the purpose, and to remove from the drawer any clear or addled ones. Eggs that are progressing favourably will show the embryo chickens in the form of dark spots, from which blood-red veins issue in many directions. On turning the eggs, the embryos will be seen to slowly rise to the surface. In the unfertile eggs nothing will be noticeable, while in the addled ones the dead embryos may be seen in the form of dark masses fixed to the lining membranes of the shells, or in cloudy masses that fall to the lower part of the eggs when they are slowly turned round. The eggs should again be tested on the fourteenth day, and any containing dead embryos should be removed, as putrefaction is liable to set in, and cause injurious gases to be thrown off, to the detriment of those progressing favourably. Clear eggs taken from the machines on the seventh day may either be handed over to the pastrycook or kept, after being hard boiled, as food for newly-hatched chickens.
In an article of this description a few hints on the management of incubator lamps are necessary, as well-managed lamps play a great part in the successful operation of artificial hatchers. In the first place, the lamp should contain good oil, as bad oil generates less heat and causes a smoke-creating flame and sooty flues. The lamp-burner should be fitted with a clean, dry wick, which should be replaced by a new one each time the machine is operated. The lamp should be attended to daily, and the hands washed afterwards, to avoid oil coming into contact with any eggs that may be handled, as oil, such as kerosene or petroleum, if smeared upon eggs, would quickly enter the pores of the shells and injure their contents.
From the nineteenth to the twenty-first day of incubation the first faint chirp oi the fully-developed chickens may be heard, and it is at this time that the eggs need special attention. The moment the first chirp is heard, or the first shell is seen to be fractured, the egg - drawer should be kept closed for twenty-four hours, after which it may be opened, and any empty shells and chickens removed. The latter should be placed in the drying-chamber fitted to the machine. Having replaced the egg-drawer, it should remain closed for another twenty-four hours, when all the chickens should be out.
In the event of any live eggs failing to hatch out on the twenty-first day, it will sometimes be found necessary to help the chickens out of the shells. This is an operation which requires considerable care. Before it is undertaken, however, the eggs which remain unpipped should be immersed for a minute or so in water warmed to 100°. This will have the effect of softening the lining membranes, and give the little prisoners a better chance of effecting their release. Should this fail, proceed as follows. Make a small puncture with a penknife in the large end of the egg, exposing the air-space, wherein, if the chicken possesses any vitality, its beak should be visible. This will admit air to its lungs, and should enable it to emerge without further assistance.
Instances have been known where incubation has been retarded from various reasons for as long as three days; but these chickens are, as a rule, poor weaklings, which it is a waste of time to attempt to rear.
The chickens should remain in the drying - chamber until dry, which should be in about twelve hours, after which, if they are to be sent to customers as " day-olds," they should be packed and quickly put on rail, as advised in my previous article.
Before leaving this subject, there are a few vital hints which may be introduced to emphasise or supplement the preceding remarks.
Let it be borne in mind that, in order to succeed with artificial incubation, the main points to be observed are: (I) The selection of the incubator; (2) the selection of the eggs; (3) the ventilation of the egg-chamber in the incubator; (4) the regulation of temperature; and (5) turning the eggs twice daily while in process of incubation.
Too much curiosity and anxiety is the cause of many failures. The most difficult part of the operation is to abstain from interference with the egg-drawer. Just at the time when they are coming out of the shell changes of temperature in the incubator are fatal to young chicks.
How a recently laid egg looks when viewed by means of the lamp
A fertile egg on seventh day of incubation
An unfertile egg at the same stage
A fertile egg on the fourteenth day
Chicken ready to come out
Chicken coming out Copyright, Chas. H. Hearson
It is well known that when a hen is on the nest, engaged in hatching, nothing will induce her to expose the eggs after she is aware that the chicks are coming out. She will leave the eggs at other times to get food and water, but not while the chicks are hatching. So soon as the eggs begin to hatch, therefore, close the drawer and keep it closed until as many of the chicks are out as can be expected.
Inquisitive neighbours who wish to be gratified should be told that they cannot be accommodated. Keep the drawer shut and have patience. The result will be more satisfactory than would be the case if the chicks were exposed to changes occasionally.
Finally, there is one other danger to which chickens hatched in incubators have been found liable, and to which those hatched under hens are strangers. It has been found that some chicks are deformed without any apparent reason. This, it is now believed, is caused by too hasty movements of the egg-drawer when it is opened to air the eggs. If the drawer is pushed back hastily the eggs are jarred, and the members of the embryo chick are liable to be jolted out of place. Gentle handling will prove a sufficient safeguard against any such risk.
In regard to the operation of incubators generally, and the avoidance of failure with such machines, it must be borne in mind that all machines are not operated in precisely the same manner, and this makes it important that the novice should not only be acquainted thoroughly with what has been previously written, but that she should make a point of studying carefully the particular instructions issued with the make of machine she is called upon to work.
In the first two articles of this series I have indicated the way in which money may be made out of day-old chicks, and I venture to hope that the details given are sufficiently intelligible to make the methods clear to the veriest tyro. Arising out of the production of chickens artifically comes the question of rearing them, and how to accomplish this successfully by means of a brooder I shall endeavour to make plain in my next article.
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