COMPARATIVE VALUE OF CATTLE FOODS.

THE attention of the farmers of the country is now turned with more earnestness than ever before, to the raising and fattening of cattle and sheep, and for this there are several concurrent reasons.

The abrogation of the so-called reciprocity treaty, and the restrictions hereafter to be placed on the introduction from Canada of cattle and sheep, which have been brought to our markets in great numbers, afford a sufficient reason for increasing our own production.

The rinderpest, that terrible disease that has proved so fatal to the cattle and sheep of Europe, will long show its effects, and the destruction of so many thousands of cattle in England cannot fail to advance or sustain the price of our own beef. Another very strongly operating reason is found in a steadily growing feeling among the farmers of the west and northwest, that it will hereafter be more profitable to devote a larger portion of their lands to the production of meat and wool than to keep them exclusively for wheat growing.

The rates of transportation have been placed so high, that many farmers cannot send their grain to market at a paying price. Such-and there are thousands will only grow grain enough for their own home consumption, and raise and feed cattle and sheep, which can be brought to market at less cost.

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That the economical management of food in fattening domestic animals is of the highest importance, no one will for a moment deny; yet how few among our farmers are really acquainted with most of the great principles which are involved, or understand the causes of which they in their practice see only the effects. They learn from experience that some kinds of food contain greater fattening properties and some greater milk-producing qualities than others, yet are content with this imperfect practical knowledge, and pay no attention to an investigation of the causes of these differences.

It may be said that the education of our farming population precludes the possibility of such investigation. This is true in a measure, and the labors of some of the deepest thinkers and most scientific men of the age, although absorbed in this special department, have added still more to the difficulties attending the study of this exceedingly interesting subject by the employment of terms and experiments only adapted to the comprehension of those who have already acquired at least a partially scientific education. But although this fact may partly account for the existing lack of knowledge of this branch of natural science, there is no doubt that the greater portion of it is attributable to the common habit of neglecting to investigate phenomena constantly under our notice, because of our familiarity with them.

It is not, of course, to be expected that the farmer can have opportunities for scientific investigation of these phenomena, but it is not unreasonable to suppose. that he might, in the common experiments which he is constantly making, by a judicious observation and analysis of some of the results, arrive at a sort of system, capable of a practical arrangement and adaptation, instead of following the beaten track of routine adopted by his ancestors, without even an effort at improvement. It is not enough that he should know that some kinds of grain or some roots possess fattening properties exceeding those of others, but he should understand why this is the case, and be able, in the possession of this knowledge, to arrive at the greatest results with the smallest possible outlay.

It is not only necessary that he should understand the values of the different foods, so that he can make the most judicious use of them, but he should understand the principles by which they operate and become available to him, and thus be enabled to employ those containing the most desirable elements for each particular purpose.

We have said that most of the literature on the subject of economical nutrition is, by the employment of obscure language, generally unintelligible to the farmer. We will therefore in the present article, avoid such language, and when we have occasion to use any of the experiments given by former writers, we will so far simplify them as to place them within the easy comprehension of all.

It is of primary importance to know the constituents of the body of the animal before we consider the food to be given it; and we will, therefore, make an analysis of the matured flesh of ruminating animals, to which class the present paper is intended more especially to apply.

In the proportion of one hundred parts there exist, approximately—

Water enters largely, as will be seen above, into constituents of all animal bodies; all the fluids, as well as the solids, are largely composed of it, and it is therefore absolutely essential in the food to a certain extent; but we shall find, hereafter, that the foods which contain it in the largest quantities are of a less nutritious character than others which have it in less quantities in their composition. It is found in the different vegetables used as food in the following proportions:

The relative fattening properties of these vegetables will be discussed hereafter.

Gelatine is the material of which many of the tissues of the body are principally composed. It consists of several kinds, all nearly related, such as horn, gelatine in bones, and in cartilages. Horn is constituted nearly like albumen. It is one of the principal elements of all animal bodies, and the skin, hoofs, (or nails,) hair, and coating of the mucous membranes, the lining of the cavities of the intestines, the windpipe, mouth, and, in fact, the lining of all the cavities and surfaces of the body are largely composed of it; but these substances, although in close affinity with each other, differ considerably in their qualities, and some possess elements hardly found in others. For instance, sulphur is found in the smallest quantity in the skin and coating of the mucous membranes, but is quite abundant in the hoofs and horns, and more so in the hair. The gelatine in the cartilages and bones, although different in each, is nearly identical; they are both soluble in hot water, and coagulate, when cool, into a thick jelly, such as we observe in cold veal broth. Glue is formed of gelatine. It is present in the bones, and composes largely the fibres of the sinews and lig aments, to which it furnishes elasticity and strength.

Fat, the next important constituent, is composed principally of starch, gum,

and sugar, and occurs in all animals, sometimes to the extent of ten per cent., and even more, of their entire weight. There are three kinds of fatty substances entering into the composition of bodies, viz: Oleine, margarine, and stearine. "Oleine is the chief component of all oils, and denotes their characteristic parts, which slowly coagulate by cold." Oils also contain another fat-margarine-which hardens quicker than oleine, and is observed in the form of crystals of the appearance of mother-of-pearl; hence it is called sometimes" mother-of-pearl fat." Stearine is the principal fat in animals; it is of a firmer texture than the others, and is the fat of mutton and beef, in which meats it is combined with margarine and oleine.

Fat is secreted in the largest quantities from food abounding in sugar, starch, and gum. These contain the three elements-carbon, hydrogen, and oxygen; the first element preponderating to the extent of at least fifty per cent.; hence these foods are called carbonaceous, or heat-giving foods. They seem to be of no great use in building up the body, but furnish, as we may say, the fuel by which the animal heat is maintained. The process by which this heat is produced is precisely similar to that of the burning of coal, gas, or other substances. The carbon of the food is exposed to the action of the oxygen of the air in the lungs, and the result is the burning of it, which produces as much heat as if consumed in the open air. Less heat-giving food is needed in hot weather than in cold, and less in warm climates than in cold. Thus the Esquimaux and Greenlanders are enabled to subsist on, and even require, fat or oily food that would be rejected by people living in a warmer climate. The body needs only a certain quantity of heat-giving food to maintain its natural temperature, and all consumed in excess of this quantity but furnishes material for future use, to be stored up in receptacles provided by nature in the body.

An accumulation of fat in the animal, caused by feeding it upon foods which abcund in fat-forming principles, is therefore really food stored up in the animal for its support when needed.

Phosphate of lime, or bone lime, is composed of about 75 per cent. of lime and 25 per cent. of phosphoric acid. It occurs in all the animal tissues, and forms from 50 to 60 per cent. of the materials of the bones, to which it gives strength, and in which it occurs in the largest quantities in those most exposed to mechanical influences. Some foods furnish an abundance of this mineral, as Indian corn, and animals which have been fed upon it to any great extent are observed to be large-boned.

Carbonate of lime, or chalk, occurs in all bones, though in much less quantities than the preceding mineral. It is also found in less proportions in young than in old animals, being nearly from 1 to 4 parts in newly-born, 1 to 6 in adult, and 1 to 8 or 9 in old animals.

Albumen occurs in the blood and nerves of animals. It differs from fat in its composition, having the four elements-carbon, hydrogen, nitrogen, and oxygen-while fat contains but three.

All the organs of the bodies of animals contain these four elements, and food must necessarily contain them to be nutritious. We found the carbonaceous foods to be fat-producing or heat-giving. The nutritious foods containing the four elements are called nitrogenous or flesh-forming foods. They are all included in the three forms, albumen, fibrin, and casein, which contain the four elements in nearly the same proportions. Albumen, occurring in the blood and nerves of animals, and in eggs of birds, &c., is found in grains and vegetables in almost exactly identical composition. Boussingault gives the results of analyses performed by Messrs. Dumas and Cahours to prove this fact, as follows:

Fibrin is the principal element of which the muscles of animals are formed; it also forms the clot and globules in blood. Like albumen, fibrin is found in vegetables in nearly identical composition with that of animals. The analysis of Messrs. Dumas and Cahours give the following:

Casein is found in the milk of mammals, and is identical with that called legumen, of the leguminous seeds, such as beans, peas, &c., in which it exists more abundantly than in milk itself. The analyses before referred to give the composition of the animal and vegetable casein as nearly identical.

The similar composition of these three substances is evident from the above. Casein seems to constitute the most nourishing portion of milk, which is undoubtedly the standard of food, as furnishing all the essential principles for the support and growth of animals; and we shall find those foods to be the most nutritive which contain casein in the greatest abundance.

The salts and other minerals found in mammals, or phosphate of magnesia, which occurs in small quantities in the bones and fluids; fluoride of calcium, which is found in small quantities in the tissues, but more abundantly in the bones and teeth; silica, a flint which is found in the enamel of the teeth; chloride of sodium, (or common salt,) which exists in all the tissues and in blood, form at least six parts in one thousand.

Of these minerals, salt is the only one that is not supplied in vegetable food in the necessary quantities, and it is therefore absolutely necessary that it should be provided, not only because no tissue of the body can exist without it, nor the blood and cartilages maintain their proper constituents, but it is necessary in the wear and tear of the body to replace that which is abstracted from the blood by the excretions, for the urine and excrement, the tears and horny substances, have all taken it from the blood, and it must be replaced. Salt, then, is necessary to the successful management of stock, and should always be given in quantities sufficient to satisfy the cravings of nature.

In a brief review of the analysis of the bodies of mammals we find them to

*The term nutritive will be used in this article for convenience, as combining the fleshforming and fat-forming elements,

consist in great part of water, which is absolutely necessary in the food to be given them for nourishment, both to assist in digestion and to replace the waste which is going on, not only in the fluids, but also in the solids; gelatine, of which many of the tissues are composed; fat, which is composed principally of starch, gum, and sugar, and requires food containing these constituents to increase its secretion; phosphate and carbonate of lime, forming the bones; albumen, casein, and fibrin, forming the flesh; and various salts and chemicals contained in small quantities, but nevertheless essential, and must therefore be furnished by the food.

We will now consider the various foods used in sustaining these different parts, and their relative and comparative values for both nourishing and fattening purposes.

We have said that milk is the type of all animal food. This is apparent from the fact that in it are found all the principles necessary to support life. It is at once a liquid and solid food; a source of albumen and of fatty substances, of sugar and the salts; and, although more abundant in water than the blood, it possesses, in its principal constituent, casein, one of the most necessary elements in the food of all mammals.

The average of several analyses in this country is as follows:

The following are analyses of the milk of different cows, as given by Bous

singault:

It will be perceived by these analyses that there is over eighty per cent. of water. This, at the first glance, would lead us to question its value as food, particularly as some of the roots which abound in water to the same extent are notoriously unnutritious; but if we give the matter a moment's consideration we shall see that so large a proportion is almost absolutely necessary, for we found in one analysis of the bodies of mammals that about seventy-five per cent. consists of water, which in the decompositions of the body is continually passing off, and which must be replaced. A recent writer says of this fact: If life consists in a metamorphosis of the tissues, fluids are an indispensable condition of life, for the combinations and decompositions in its substance produced by the activities of the body cannot take place without the agency of water, and since the last result of the whole process of digestion is a liquefaction of alimentary principles, the

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