| Aibumi- noids. |
Fat × 214. | Carbo- hydrates. |
Salts. | |
| 1 ℔ Potatoes | 6·5 | 0·0 | 41·0 | 2·0 |
| 1 ℔ Bran | 15·5 | 9·0 | 44·0 | 6·0 |
| 22·0 | 9·0 | 85·0 | 8·0 | |
| +9·0 | ||||
| 94·0 |
Adding here the fats × 214 to the carbohydrates, we get the ratio of the mixture as 22:94, or about 1:414, which is very good. Coming next to the maize, let us suppose that it is desired to feed this as grain in the evening, and to “balance” it by an equal weight of “mash” or soft mixture in the morning. One way would be as follows:—
| Aibumi- noids. |
Fat × 214. | Carbo- hydrates. |
Salts. | |
| 3 ℔ Maize (×3) | 31·5 | 54·0 | 199·5 | 4·5 |
| 1 ℔ Horse-flesh | 21·7 | 5·8 | 0·0 | 1·0 |
| 2 ℔ Ground oats (×2) | 30·0 | 24·8 | 96·0 | 5·0 |
| 83·2 | 84·6 | 295·5 | 10·5 | |
| +84·6 | ||||
| 380·1 |
This ration explains how in such a case we must multiply the figures for maize by 3, and those for oats by 2, being the proportions we are taking to one portion of horse-flesh. The ratio of this dietary comes out slightly lower than 1:412.
The proper ratio for feeding fowls has received much discussion. Dietetic authorities mostly agree that about 1:5 is the best for maintenance of animal life generally, and more specifically that there should be of albuminoids about 18 parts in 100, of fats 7 and carbohydrates 75. That should suffice for growing chickens; but it is fairly obvious that fowls fattening may require more fat, while the constant production of eggs, whose high ratio is shown in the analyses, must require a larger amount of albuminoids. This fact is indicated by the hen herself, which when laying devours large earthworms, usually rejected with disgust at other times. She shows by this appetite how specially she needs albumen; and fowls on a wide range, though only fed with corn, may thus in summer “balance” a dietary for themselves by the worms and insects which they procure. When they cannot do this, more albumen must be supplied, and the general opinion of practical egg-farmers has tended towards a ratio of 1:4 or 1:412 for hens in full lay. One successful American breeder feeds as high as 1:3, and states that his results have been best at that figure.
Passing from theory, the greatest practical advance in poultry feeding has probably been the discovery of the benefit to be derived from dividing the extra supply of albumen between fresh bones cut up small in a mill (known amongst breeders as “cut bon”) and such green food as clover or cabbage. The bones contain a good proportion of fat, and of mineral salts also, which careful experiments have shown to be of great importance both in egg-production and for growing stock. Green food had until recently been looked upon chiefly as a corrective, or necessity for health, though it was known that fowls on a pasture grazed largely. But the nutritive ratio of clover is as high as 1:3, and American poultry-farmers now use it largely as really albuminous food, to promote laying. Its use in this way also allows more animal food to be used without ill effect; and to this free use of clover and cut bone in conjunction the improved results upon American egg-farms are largely due. The following is the “mash” ration on a successful American egg-farm, and represents a high forcing diet: middling or sharps 100 ℔, maize meal 75 ℔, gluten-meal (a highly nitrogenous by-product; of American flour-milling) 25 ℔, clover-meal 80 ℔, meat-meal 35 ℔, all weighed dry, mixed with boiling water in the evening, and kept covered all night.
The majority of poultry-farmers give their stock each day one feed of grain, and one of soft meal-food or “mash,” but by no means agree as to the times for these meals. In England, morning mash and evening grain are almost universal, the latter giving more support during the long fast at night, and the former more rapid recuperation on cold mornings. But in America and Canada, where the climate compels confinement of the fowls for months together in enclosed sheds, health and eggs can only be secured by constant “scratching,” to promote which the grain is scattered amongst loose litter spread several inches deep. Many, therefore, prefer to scatter the grain in the morning and feed the mash at night, alleging that a good breakfast of mash makes the fowls lazy, with bad results. Others state that this is avoided by a rather scantier morning feed of mash, with a slight sprinkle of grain in the litter afterwards. In 1890 a careful experiment was made by the Massachusetts Agricultural College, two similar lots of pullets being fed upon similar food, on the two plans, for two periods of several months each, in summer and winter seasons, and each lot receiving, besides the morning and evening feeds, a slight sprinkle of millet in the litter, to promote exercise. In egg-production there was scarcely any difference, what little there was being in favour of the morning mash; and the birds thus fed became also somewhat the heaviest. The most remarkable result was that the weight of manure voided in the night was nearly double in the case of the evening-mash birds, showing the rapid digestion of mash food.
Artificial Incubation and Rearing.—In the separate article on Incubator, details are given concerning the appliances used in artificial hatching and rearing, and the subject may be only briefly treated here.
Even in England the eggs hatched in incubators now probably equal, or nearly equal, those hatched under hens: in America the wide practice of artificial incubation is difficult to realize. Of small-sized machines one Illinois maker sold 14,800 in 1899; and in regard to large sizes, in 1900 at least seven names and addresses were known of operators who each used from 55 to as many as 85 machines, every machine holding 300 or more eggs: somewhat smaller plants were of course far more numerous. Experience on such a vast scale has led to a practical advance of considerable importance. While in England it is still usual to effect empirical adjustment of ventilation and moisture, the better American incubators now dispense with direct moisture altogether. It was remembered that the hen hatches without moisture, and equally so the egg-ovens of Egypt; the absence of direct air-current, and consequently of any rapid evaporation, being the obvious explanation. The manufacturers therefore set themselves to slow the movement of the air; and when this object was effectually accomplished, it was found that there was no need for moisture, and that the chicks also hatched out stronger and in higher proportion. The general opinion in the United States, where many farmers tested both hens and machines on a large scale, whilst still undecided between them, is that the proceeds of artificial incubation are superior by about 10%, and this is based upon hatches of thousands annually.
Artificial hatching necessitates artificial brooding, and in this also great changes have taken place, any real success in rearing having been for some years far behind that in hatching. The method universally attempted at first might be called the “coverlet” system, nestling material such as strips of flannel or wool, warmed from above, being provided for the chicks to nestle under, as they do under the feathers of the hen. Many were reared in this way, but failures were also terribly general, and these were ultimately traced to confinement and pollution and heating and re breathing of the air, caused by the nestling material. That system is now abandoned, warmed but open chambers being provided, which the chicks use at pleasure, but which have no coverlet to rest upon their bodies. In some, heated pipes traverse the upper part of the chamber, some inches above the chicks; in others a warm iron plate radiates heat in the same way; in others warmed air is brought in by flues or openings; in some small ones the lamp itself burns in the chamber of the brooder: but the principle is common to all of a warmed shelter, open above, and generally with an outer chamber also, sheltered but not heated, which breaks the transition to the open air outside. In America a very large proportion of the chickens reared are brought up till hardy in the large “brooder-houses” mentioned below.
