The main rules governing artificial incubation are applicable to all types of machines. There are of course certain points in con nection with the working of particular machines which must be adhered to, and it is as well to make a study of the instructions sent out with the machines. Care should first be taken to select a suitable building. It must be ventilated, without draughts; atmos pheric conditions must be sufficiently moist; and the room tem perature should be as steady as possible, not falling below 6o°. To secure the real benefit of extra moisture it is essential to have the room at the desired temperature. The next point is to see that all incubators are level, and arranged to secure free access to each one without disturbing the others. The interior and exterior fittings must be kept clean and in workable condition, and the thermometers should be tested at least once during the season. The machines should be regulated so that the damper or regulating device controls the temperature at 103°, as the heat from the eggs after a few days' incubation will tend to raise the temperature at least one degree. Many poultry keepers overheat the machines during the early stages, and this has a harmful result on the embryos. All machines should be maintained at the desired temperature for 24 hours before filling with eggs.
The best quality eggs should be selected, representative of the breed. Size and weight must be studied, and eggs should weigh approximately 2i oz. in the heavy breeds, and 21 oz. in light breeds. Abnormal eggs over a week old should be discarded, as these often fail to hatch. The eggs should be allowed to warm up gradually after they have been placed in the machines ; this can be done by lowering the flame for a few hours. On the third morn ing the eggs should be turned, and from then onwards turn three times daily up to and including the z gth morning. Airing is not essential throughout the period. Moisture must be applied when needed, not later than the end of the first week, and sometimes earlier. The results of the first hatch usually provide a clue as to right amount and period. Eggs should be tested for fertility as early as possible after the seventh day and handled carefully in testing. There should be no interference with the eggs or chicks in the hatching period. Any oversight in management cannot be rectified at the eleventh hour. The morning of the 22nd day is quite soon enough to open the machines; opening earlier than this tends to liberate the moisture, so essential during hatching. After every hatch the machine should be disinfected and examined.
Rearing.—Rearing is more difficult than hatching, but here again modern appliances play an important part in successful rearing. There is a choice between anthracite stoves, blue flame hovers, radiators and small unit appliances, and the selection of any of these will depend very largely on the numbers to be reared. Medium sized units of about 25o to 35o chicks under anthracite stoves do well, and slightly smaller numbers under blue-flame hovers. Farmers needing only small numbers of chickens are able
to use the small unit outdoor brooders. The main factors to bear in mind are a steady and fairly high temperature (go°) for the first two weeks, to be followed by a steady fall up to weaning stage. Floor draughts must be avoided, and full advantage taken of sunlight. Cleanliness is most important, and overcrowding must not be tolerated. Access to grass runs is advisable after the first week. As the chicks develop and reach weaning age, the sexes should be separated, and the pullets housed in small flocks of from 5o upwards, the number depending upon the space available. Perching accommodation should be provided when three months old—before, if there is any tendency towards crowding at night. Feeding from shell to maturity should be on liberal but economic lines. Ill balanced rations will increase the rearing risks.
Feeding.—A system which has been successfully practised for a number of years, embodying the dry mash method plus the usual grain allowance, is as f ollows :—(a) For the first week give four meals daily of drychick food, composed of 2 parts (by weight) of cracked wheat, 2 parts maize grits, and 1 part pinhead oatmeal. (b) After the first week allow three meals daily of above, plus a dry mash made up as follows :-3 parts (by weight) of bran, I part each of thirds, maize meal, Sussex ground oats, and fine alfalfa, a part dried meat, a part sterilized bone meal, 4 part fine charcoal, and 2% of total weight of cod liver oil. The chicks have full access to this mash at all times, with semi-solid butter milk (one pint milk to two gallons water) to drink. (c) When old enough to leave brooder house, a grain ration of 2 parts whole wheat, to 1 part cracked maize is given in place of the first mixture, together with a mash ration slightly different from the one already given, viz., 3 parts bran, 1 part thirds, 1 maize meal, 1 Sussex ground oats, part meat meal, or part fish meal, and 4 part sterilized steam bone flour. This mash and grain is fed to the birds until they reach the adult stage, when ordinary rations are allowed. If preferred the mash throughout the growing period can be given in a moist state, but this involves much more labour, especially when large numbers are at stake, and the results do not seem to justify the expense. It is desirable, however, to feed on the lines to be adopted at maturity, and if there is any possibility of the pullets receiving any wet mash later, then it becomes neces sary to educate them to this method. It is more difficult to en courage wet mash reared birds to consume dry mash than vice versa. Before removing pullets to their laying quarters, culling should be practised on rather vigorous lines. In large flocks there are certain to be a few undesirables, and such birds should be marketed at the earliest possible date. Environment plays an important part in the development of the birds, and the more natural the surroundings throughout the growing period, the more robust will the stock become.