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During the transition from the wild state, and when the new variety, "the domestic animal,” is established, numerous circumstances may be brought to bear with important influence upon the development. Reverting to what has been stated under "development in the natural state," we find the modifying circumstances to be, selection, the strong having the advantage; destructive influences tending to remove the weak and diseased; food possessing the elements of nutrition and respiration in due proportion; and legitimate exercise of all the organs of the body. All these are in greater or less degree under our control when animals become subject to our influence.
Selection we can arbitrarily arrange according to our ideas of fitness or our object in the production of new characters; the various destructive influences we can ameliorate, if not remove; the elements of food we can apportion with almost chemical exactness, whether we desire an excess of fat or filesh producing materials; and most of the organs of the body are directly or indirectly under some degree of control.
Experience and observation having demonstrated the possession of a power to influence the animal's qualities and physical conformation, it becomes immediately a matter of inquiry, how far it is possible to proceed. Experiments dictated by fancy or founded upon calculation are made, with variable results ; new facts are discovered, and a gradual progress is made towards the foundation of a system. According to the object desired will the aggregate result be apparent; one aims at producing bulk and physical strength, another speed and lightness; a third sees a special gain in color, or some particular line in conformation.
It would far exceed our limits were we to attempt an extensive examination of the subject; nor would any advantage accrue, as the animals with which we are more immediately concerned afford sufficient evidence for the support of our argument: we have only to point to the existing breeds to prove what changes may be effected by attention to the circumstances which influence development. It is not advisable to indulge in speculation, but we presume it can hardly be questioned that there was a time when Devons, Herefords, Short-horns, and Long-horns, did not exist as we know them now; nor can it be doubted that the varieties, compared with their originals, could such be found, would present modifications 80 marked as to lead to reasonable doubts of their having descended from å race so apparently distinct.
Advancing rapidly to the practical section of the subject, it may be advantageous to indicate the position we have been endeavoring to establish.
At the commencement we explained the meaning attached to the term “Early Maturity," and referred to general observation and experience to
prove that in cultivated breeds maturity is attained more rapidly than under natural conditions. In considering, in the next place, the universal idea that what is rapidly produced is wanting in durability, we found it necessary to accept the fact as established by general observation, and ex. plained, on the principle, that permanent combinations can only be effected under proper conditions, time being one of the essentials. The differences between the circumstances of the natural and domestic states were next discussed, as affecting the development of the tissues, the gen. eral conclusion being deduced that important modification of form and quality may be effected by regulating the condition of the animal's existence, according to the object we have in view.
It being conceded that there is a possibility of controlling the animal's development, and producing such alterations of physical form and qualification within certain limits as may be determined upon, it is very important that the power should be exercised with circumspection. How far this is the case will appear as we proceed.
Whatever minor objects may be kept in view in cultivating certain kinds of animals, there is ample evidence to prove that the paramount one is to lose as little time as possible in fitting the animal for his intended purpose. Without any qualification that statement must be made; in obedience to the spirit of the age, every thing must move rapidly to its destination, and animals, as well as machines, must be brought to the greatest perfection in the shortest space of time; failing which, in either case, no superiority in other respects can save from condemnation.
Imagine a breed of sheep, furnishing mutton of a quality hitherto unknown, rich in nutriment and of rare flavour, but insipid and unwhole. some, until the animal had reached the age of 4 or 5 years; not the pos session of all the qualities is excess that make the best varieties valuable, could render such a breed popular, save with the wealthy epicure. Ex tend the same reasoning to horses; establish a breed possessing every requisite, opposed by the single objection that the animal must be 6
years old before he could be used, and the extinction of the race would be certain. Further illustration can not be necessary to prove what hardly any one can doubt, that the tendency of the whole system of the present day is to force animals by every available means to a premature adultism; and to call into active exercise the powers which are yet imperfect, for the reason that one important condition, TIME, is wanting. Upon different animals this forcing system will produce results varying, in some degree, according to the characteristics of each ; there are, however, certain inevits able consequences which affect all in a nearly equal degree. These may be termed the general results, while the others having reference to each breed may be distinguished as the particular results.
GENERAL RESULTS OF THE FORCING SYSTEM.
Early maturity, if legitimately attained, is doubtless a desideratum; but in the anxiety to exceed the ordinary rate of development, too little regard is paid to the possible production of disease. Animals are highly fed, kept in a warm temperature, denięd a proper amount of exercise, and yet no ill results are anticipated; and, in the event of active disturbance supervening, there is immediately a wondering inquiry as to the cause, as if every circumstance in the animal's treatment did not deserve the title.
Taking the whole system of management, we find all the conditions tending to the same results: the food, the stationary position, and the warm temperature, all unite to diminish expenditure and facilitate excessive deposition. Of these three, the food supplied exerts the most decided influence, by furnishing an abundant material for the support of the body. Fatty tissue becomes abundant enough in a comparatively short time; but the muscular structure does not experience any improvement, on the contrary it deteriorates. This fact universally admitted is worthy of profound consideration. The food contains more elements than necessary for the development of muscle (filesh) as well as of fat; the various oil-cakes and all kinds of grain on which animals are fed, contain a large percentage of flesh-forming elements, as well as a quantity of the elements which form fat; so that if the two were equally assimilated and deposited, the animals would show as much flesh in proportion as fat. Instead of this being the case, fat elements are invariably assimilated in far larger proportion than the elements of flesh. Not only so, but more remarkable still, the fatty tissues encroach upon the flesh and other parts, leading to a fatty condition of all the muscles, the fibres of the heart, the structure of the liver, and nearly every part of the body where the deposition can possibly occur.
Reasoning upon this preference for the one tissue over the other, we are required to remember that flesh or muscle is a highly organized structure, possessing vital properties; that all the movements of the animal body, the action of the heart
, the motions of the digestive organs depend upon the exercise of the characteristic power of muscular contraction.
For the proper development of this important and extensively-diffused structure, not only is nutriment necessary, but also bodily exercise, which improves the circulation, increases the secretions, and, by aiding the removal of the worn-out tissues, assists the development of the new. The conditions, however, which are essential for the growth of muscle are absolutely opposed to the deposit of fat, which is not a highly organized tissue, which has no vital functions, but is a chemical substance simply deposited in a membrane of most simple construction.
Fat plays a very important part in the system; but its offices are solely chemical or mechanical. It forms in many parts soft cushions, it regulates the temperature of the body by offering the escape of heat, and its most important duty is to furnish elements for the support of respiration; elements which may combine with the oxygen of arterial blood, and by the results of the combination contribute largely to the heat of the body.
The destruction of fatty elements will be in direct proportion to the activity of respiration, circulation, and excretion; consequently exercise is opposed to the accumulation of fat, and rest favors it. An animal at rest does not inhale any large amount of atmospheric air; his circulation is slower than it would be during exertion; excretion is diminished, therefore there is but little destruction of fatty elements. If under these circumstances an abundance of those elements is given in the food, a large amount is stored up in the system, in various parts even to the exclusion of muscle or flesh, which cannot be developed although its elements are largely consumed; because there is an absence of those healthy conditions of respiration, circulation, and excretions, which are indispensable for the elaboration of so vital structure.
An objection may possibly be made to the use of the word disease as applied to mere excess of healthy tissue. It may be urged with apparent justice, that a certain proportion of fat is necessary in the most perfect state of health, and that therefore there can be no very serious evil in an excess of what is harmless or even desirable. We have no desire to escape this position by advancing the language of the schools upon the subject of disease; but accepting the popular idea of the matter, let us suggest in reply that a small quantity only of fat is necessary, that its excess increases the size of the body without any advantage being gained; that when it usurps the place of other tissues it interferes with the functions of those parts; that a heart in such case can not properly distribute the blood; a liver so affected cannot secrete healthy bile; and that if these functions are imperfectly performed, the system must suffer according to the extent of the derangement.
In reply to the general objection that the material whose excess is characterized as disease is itself a healthy tissue, it may be observed that no structure is more healthy or of more importance to the animal than bone, and yet nothing can be conceived more dire than its deposit in the brain or the heart, or more serious than its encroachment upon other parts; a structure, however necessary in due proportion and in proper place, is even on this principle injurious in excess, or when out of its proper situa: tion.
Nitrogen or flesh-forming elements being present in considerable quantity in most kinds of food used for fatting animals, it is necessary to account for their consumption in the animal economy. The flesh being rather lessened than increased, it follows that the nutritive elements are not properly appropriated: the question then arises—What becomes of them? Many substances that would be injurious, or at best useless in the system, escape digestion by reason of their insolubility and are expelled as excrementitious; not so, however, can we get rid of all the nutritive elements of food which are digestible, and although when given in excess a large proportion may pass unassimilated, a larger portion is digested and taken into the circulation.
Without assuming any power of tracing the nitrogenized elements through the digestive process, we may form a very natural conjecture as to their destination from one fact, viz., that in fat animals there is always a large increase of the fibrin of the blood. Whatever may be the actual relations of this material to the nutritive function, it will not be necessary now to decide; but its chemical relation to the nitrogenized elements of food lends a sanction to the idea that it is derived from them.
An animal in perfect health, undergoing regular and proper exercise, and receiving a due quantity of food to supply the wants of the system, has no more than 1 or 2 parts of fibrin in 1000 parts of blood; but lessen the activity of the muscular system, or impair the nutritive function, and the proportion is immediately increased. Give an excess of food, and at the same time diminish the wants of the system by so arranging the ani. mal's position that there shall be the least expenditure; and the fibrin will rise to 6 or 7 parts in 1000. An inflammatory attack leads to the same result by its interference with the nutrition, and curiously in extreme debility the same excess is noticed, the animal in such case literally feeding on its own tissues; thus in each instance the immediate result of non-deposition of flesh or muscle is excess of fibrin in the blood.
The state of comparative inactivity in which the animal is kept is favorable to the production of debility. Important functions, as circulation, respiration, and excretion, are sluggishly performed: the various organs, receiving therefore an insufficient supply, lose their tone, and in course of time decrease. The diminution of a structure from disease is a fact familiar to most people; even an injury, which necessitates the inaction of an arm or a leg for a few weeks, will be attended with a very perceptible decrease of bulk. Alterations so apparent in the short space of a week or two enable us to form some idea of the effects of rest continued for months, and prevent our being much surprised at the statement, that parts when entirely thrown out of use in process of time disappear.
Thus the animal is not only receiving an injurious excess of food, but