The Principles of Breeding Part 2
You’re reading novel The Principles of Breeding Part 2 online at LightNovelFree.com. Please use the follow button to get notification about the latest chapter next time when you visit LightNovelFree.com. Use F11 button to read novel in full-screen(PC only). Drop by anytime you want to read free – fast – latest novel. It’s great if you could leave a comment, share your opinion about the new chapters, new novel with others on the internet. We’ll do our best to bring you the finest, latest novel everyday. Enjoy!
The others we will suppose to have been placed on the hill-sides of New England, or on the barren Isle of Jersey, or on the highlands of Scotland, or in the pastures of Devons.h.i.+re. These being obliged to roam longer for a scantier repast grow more slowly, develop their capabilities in regard to size not only more slowly, but, perhaps, not fully at all--they become more active in temperament and habit, thinner and flatter in muscle. Their young cannot so soon s.h.i.+ft for themselves and require more milk, and the dams yield it. Each generation in its turn becomes more completely and fully adapted to the circ.u.mstances amid which they are reared, and if bred indiscriminately with any thing and every thing else, we by and by have the common mixed cattle of New England, miscalled natives; or if kept more distinct, we have something approaching the Devon, the Ayrs.h.i.+re, or the Jersey breeds.
A due consideration of the natural effect of climate and food is a point worthy the special attention of the stock-husbandman. If the breeds employed be well adapted to the situation, and the capacity of the soil is such as to feed them fully, profit may be safely calculated upon. Animals are to be looked upon as machines for converting herbage into money. Now it costs a certain amount to keep up the motive power of any machine, and also to make good the wear and tear incident to its working; and in the case of animals it is only so much as is digested and a.s.similated, _in addition to the amount thus required_, which is converted into meat, milk or wool; so that the greater the proportion which the latter bears to the former, the greater will be the _profit_ to be realized from keeping them.
There has been in New England generally a tendency to choose animals of large size, as large as can be had from any where, and if they possess symmetry and all other good qualities commensurate with the size, and if plenty of nutritious food can be supplied, there is an advantage gained by keeping such, for it costs less, other things being equal, to shelter and care for one animal than for two. But our pastures and meadows are not the richest to be found any where, and if we select such as require, in order to give the profit which they are capable of yielding, more or richer food than our farms can supply, or than we have the means to purchase, we must necessarily fail to reap as much profit as we might by the selection of such as could be easily fed upon home resources to the point of highest profit.
Whether the selection be of such as are either larger or smaller than suit our situation, they will, and equally in both cases, vary by degrees towards the fitting size or type for the locality in which they are kept, but there is this noteworthy difference, that if larger ones be brought in, they will not only diminish, but deteriorate, while if smaller be brought in, they will enlarge _and improve_.
The bestowal of food sufficient both in amount and quality to enable animals to develop all the excellencies inherent in them, and to obtain all the profit to be derived from them, is something very distinct from undue forcing or pampering. This process may produce wonderful animals to look at, but neither useful nor profitable ones, and there is danger of thus producing a most undesirable variation, for, as in plants, we find that forcing, pampering, high culture or whatever else it may be called, may be carried so far as to result in the production of double flowers, (an unnatural development,) and these accompanied with greater or less inability to perfect seed, so in animals, the same process may be carried far enough to produce sterility. Instances are not wanting, and particularly among the more recent improved Short-horns, of impotency among the males and of barrenness in the females, and in some cases where they have borne calves they have failed to secrete milk for their nourishment.[3]
Impotency in bulls of various breeds has not unfrequently occurred from too high feeding, and especially if connected _with lack of sufficient exercise_.[4]
_Habit_ has a decided influence towards inducing variation. As the blacksmith's right arm becomes more muscular from the habit of exercise induced by his vocation, so we find in domestic animals that use, or the demand created by habit, is met by a development or change in the organization adapted to the requirement. For instance, with cows in a state of nature or where required only to suckle their young, the supply of milk is barely fitted to the requirement. If more is desired, and if the milk be drawn completely and regularly, the yield is increased and continued longer. By keeping up the demand there is induced in the next generation a greater development of the secreting organs, and more milk is given. By continuing the practice, by furnis.h.i.+ng the needful conditions of suitable food, &c., and by selecting in each generation those animals showing the greatest tendency towards milk, a breed specially adapted for the dairy may be established. It is just by this mode that the Ayrs.h.i.+res have, in the past eighty or a hundred years, been brought to be what they are, a breed giving more good milk upon a given quant.i.ty of food than any other.
It is because the English breeders of modern Short-horns altogether prefer beef-making to milk-giving properties that they have constantly fostered variation in favor of the one at the expense of the other until the milking quality in many families is nearly bred out. It was not so formerly--thirty years ago the Short-horns (or as they were then usually called, the Durhams) were not deficient in dairy qualities, and some families were famous for large yield. By properly directed efforts they might, doubtless, be bred back to milk, but of this there is no probability, at least in England, for the tendency of modern practice is very strong toward having each breed specially fitted to its use--the dairy breeds for milk and the beef breeds for meat only. The requirements of the English breeder are in some respects quite unlike those of New England farmers--for instance, as they employ no oxen for labor there is no inducement to cultivate working qualities even, in connection with beef.
As an ill.u.s.tration of the effect of habit, Darwin[5] cites the domestic duck, of which he says, "I find that the bones of the wing weigh less, and the bones of the leg more, in proportion to the whole skeleton, than do the same bones in the wild duck; and I presume that this change may be safely attributed to the domestic duck flying much less and walking more than its wild parent." And again, "not a single domestic animal can be named which has not in some country drooping ears, and the view suggested by some authors, that the drooping is due to the disuse of the muscles of the ear, from the animals not being much alarmed by danger, seems probable."
Climate, food and habit are the princ.i.p.al causes of variation which are known to be in any marked degree under the control of man; and the effect of these is, doubtless, in some measure indirect and subservient to other laws, of reproduction, growth and inheritance, of which we have at present very imperfect knowledge. This is shown by the fact that the young of the same litter sometimes differ considerably from each other, though both the young and their parents have apparently been exposed to exactly the same conditions of life; for had the action of these conditions been specific or direct and independent of other laws, if any of the young had varied, the whole would probably have varied in the same manner.
Numberless hypotheses have been started to account for variation. Some hold that it is as much the function of the reproductive system to produce individual differences as it is to make the child like the parents. Darwin says "the reproductive system is eminently susceptible to changes in the conditions of life; and to this system being functionally disturbed in the parents I chiefly attribute the varying or plastic condition of the offspring. The male and female s.e.xual elements seem to be affected before that union takes place which is to form a new being. But why, because the re-productive system is disturbed this or that part should vary more or less, we are profoundly ignorant. Nevertheless we can here and there dimly catch a faint ray of light, and we may feel sure that there must be some cause for each deviation of structure however slight."
It may be useless for us to speculate here upon the laws which govern variations. The fact that these exist is what the breeder has to deal with, and a most important one it is, for it is this chiefly, which makes hereditary transmission the problem which it is. His aim should ever be _to grasp and render permanent and increase so far as practicable, every variation for the better, and to reject for breeding purposes such as show a downward tendency_.
That this may be done, there is abundant proof in the success which has in many instances attended the well directed efforts of intelligent breeders. A remarkable instance is furnished in the new Mauchamp-Merino sheep of Mons. Graux, which originated in a single animal, a product of the law of variation, and which by skillful breeding and selection has become an established breed of a peculiar type and possessing valuable properties. Samples of the wool of these sheep were shown at the great exhibition in London, in 1851, and attracted much attention. It was also shown at the great recent Agricultural Exhibition at Paris. A correspondent of the _Mark Lane Express_, says:
"One of the most interesting portions of the sheep-show is that of the Mauchamp variety of Merinos, having a new kind of wool, glossy and silky, similar to mohair. This is an instance of an entirely new breed being as it were created from a mere sport of nature. It was originated by Mons. J.L. Graux. In the year 1828, a Merino ewe produced a peculiar ram lamb, having a different shape from the usual Merino, and possessing a long, straight, and silky character of wool. In 1830, M. Graux obtained by this ram one ram and one ewe, having the silky character of wool. In 1831, among the produce were four rams and one ewe with similar fleeces; and in 1833 there were rams enough of the new sort to serve the whole flock of ewes. In each subsequent year the lambs were of two kinds; one possessing the curled elastic wool of the old Merinos, only a little longer and finer; the other like the new breed. At last, the skillful breeder obtained a flock combining the fine silky fleece with a smaller head, broader flanks, and more capacious chest; and several flocks being crossed with the Mauchamp variety, have produced also the Mauchamp-Merino breed. The pure Mauchamp wool is remarkable for its qualities as a combing-wool, owing to the strength, as well as the length and fineness of the fibre. It is found of great value by the manufacturers of Cashmere shawls and similar goods, being second only to the true Cashmere fleece, in the fine flexible delicacy of the fibre; and when in combination with Cashmere wool, imparting strength and consistency. The quant.i.ty of the wool has now become as great or greater than from ordinary Merinos, while the quality commands for it twenty-five per cent. higher price in the French market. Surely breeders cannot watch too closely any accidental peculiarity of conformation or characteristic in their flocks or herds."
Mons. Vilmorin, the eminent horticulturist of Paris, has likened the law of similarity to the centripetal force, and the law of variation to the centrifugal force; and in truth their operations seem a.n.a.logous, and possibly they may be the same in kind, though certainly unlike in this, that they are not reducible to arithmetical calculation and cannot be subjected to definite measurement. His thought is at least a highly suggestive one and may be pursued with profit.
Among the "faint rays" alluded to by Mr. Darwin as throwing light upon the changes dependent on the laws of reproduction, there is one, perhaps the brightest yet seen, which deserves our notice. It is the apparent influence of the male first having fruitful intercourse with a female upon her subsequent offspring by other males. Attention was first directed to this by the following circ.u.mstance, related by Sir Everard Home: A young chestnut mare, seven-eighths Arabian, belonging to the Earl of Morton, was covered in 1815 by a Quagga, which is a species of wild a.s.s from Africa, and marked somewhat in the style of a Zebra. The mare was covered but once by the Quagga, and after a pregnancy of eleven months and four days gave birth to a hybrid, which had, as was expected, distinct marks of the Quagga, in the shape of its head, black bars on the legs and shoulders, &c. In 1817, 1818 and 1821, the same mare was covered by a very fine black Arabian horse, and produced successively three foals, and although she had not seen the Quagga since 1816, they all bore his curious and unequivocal markings.
Since the occurrence of this case numerous others of a similar character have been observed, a few of which may be mentioned. Mr.
McGillivray says, that in several foals in the royal stud at Hampton Court, got by the horse "Actaeon," there were unmistakable marks of the horse "Colonel." The dams of these foals were bred from by Colonel the previous year.
A colt, the property of the Earl of Suffield, got by "Laurel," so resembled another horse, "Camel," that it was whispered and even a.s.serted at Newmarket that he must have been got by "Camel." It was ascertained, however, that the mother of the colt bore a foal the previous year by "Camel."
Alex. Morrison, Esq., of Bognie, had a fine Clydesdale mare which in 1843 was served by a Spanish a.s.s and produced a mule. She afterwards had a colt by a horse, which bore a very marked likeness to a mule--seen at a distance, every one sets it down at once as a mule.
The ears are nine and one-half inches long,--the girth not quite six feet, stands above sixteen hands high. The hoofs are so long and narrow that there is a difficulty in shoeing them, and the tail is thin and scanty. He is a beast of indomitable energy and durability, and highly prized by his owner.
Numerous similar cases are on record,[6] and it appears to have been known among the Arabs for centuries, that a mare which has first borne a mule, is ever after unfit to breed pure horses;[7] and the fact seems now to be perfectly well understood in all the mule-breeding States of the Union.
A pure Aberdeens.h.i.+re heifer, the property of a farmer in Forgue, was served with a pure Teeswater bull to which she had a first cross calf.
The following season the same cow was served with a pure Aberdeens.h.i.+re bull, the produce was in appearance a cross-bred calf, which at two years old had long horns; the parents were both hornless.
A small flock of ewes, belonging to Dr. W. Wells in the island of Grenada, were served by a ram procured for the purpose;--the ewes were all white and woolly; the ram was quite different,--of a chocolate color, and hairy like a goat. The progeny were of course crosses but bore a strong resemblance to the male parent. The next season, Dr.
Wells obtained a ram of precisely the same breed as the ewes, but the progeny showed distinct marks of resemblance to the former ram, in color and covering. The same thing occurred on neighboring estates under like circ.u.mstances.
Six very superior pure-bred black-faced horned ewes, belonging to Mr.
H. Shaw of Leochel-Cushnie, were served by a Leicester ram, (white-faced and hornless.) The lambs were crosses. The next year they were served by a ram of exactly the same breed as the ewes themselves.
To Mr. Shaw's astonishment the lambs were without an exception hornless and brownish in the face, instead of being black and horned.
The third year (1846) they were again served by a superior ram of their own breed, and again the lambs were mongrels, but showed less of the Leicester characteristics than before. Mr. Shaw at last parted from these fine ewes without obtaining a single pure-bred lamb.[8]
"It has been noticed that a well bred b.i.t.c.h, if she have been impregnated by a mongrel dog, will not although lined subsequently by a pure dog, bear thorough-bred puppies in the next two or three litters."[9]
The like occurrence has been noticed in respect of the sow. "A sow of the black and white breed became pregnant by a boar of the wild breed of a deep chestnut color. The pigs produced were duly mixed, the color of the boar being in some very predominant. The sow being afterwards put to a boar of the same breed as herself, some of the produce were still stained or marked with the chestnut color which prevailed in the first litter and the same occurred after a third impregnation, the boar being then of the same kind as herself. What adds to the force of this case is that in the course of many years' observation the breed in question was never known to produce progeny having the slightest tinge of chestnut color."[10]
The above are a few of the many instances on record tending to show the influence of a first impregnation upon subsequent progeny by other males. Not a few might also be given showing that the same rule holds in the human species, of which a single one will suffice here:--"A young woman residing in Edinburgh, and born of white parents, but whose mother previous to her marriage bore a mulatto child by a negro man servant, exhibits distinct traces of the negro. Dr. Simpson, whose patient at one time, the young woman was, recollects being struck with the resemblance, and noticed particularly that the hair had the qualities characteristic of the negro."
Dr. Carpenter, in the last edition of his work on physiology, says it is by no means an infrequent occurrence for a widow who has married again to bear children resembling her first husband.
Various explanations have been offered to account for the facts observed, among which the theory of Mr. McGillivray, V.S., which is endorsed by Dr. Harvey, and considered (as we shall presently see) as very probable at least by Dr. Carpenter, seems the most satisfactory.
Dr. Harvey says:
"Instances are sufficiently common among the lower animals where the offspring exhibit more or less distinctly over and beyond the characters of the male by which they were begotten, the peculiarities also of a male by which their mother at some former period had been impregnated. * * * Great difficulty has been felt by physiological writers in regard to the proper explanation of this kind of phenomena. They have been ascribed by some to a permanent impression made somehow by the s.e.m.e.n of the first male on the genitals and more particularly on the ova of the female:[11] and by others to an abiding influence exerted by him on the imagination and operating at the time of her connection subsequently with other males and perhaps during her pregnancy; but they seem to be regarded by most physiologists as inexplicable.
Very recently, in a paper published in the Aberdeen Journal, a Veterinary Surgeon, Mr. James McGillivray of Huntley, has offered an explanation which seems to me to be the true one. His theory is that "_when a pure animal of any breed has been pregnant to an animal of a different breed, such pregnant animal is a cross ever after, the purity of her blood being lost in consequence of her connection with the foreign animal, herself_ BECOMING A CROSS FOREVER, _incapable of producing a pure calf of any breed_."
Dr. Harvey believes "that while as all allow, a portion of the mother's blood is continually pa.s.sing by absorption and a.s.similation into the body of the foetus, in order to its nutrition and development, a portion of the blood of the foetus is as constantly pa.s.sing in like manner into the body of the mother; that as this commingles there with the general ma.s.s of the mother's own blood, it inoculates her system with the const.i.tutional qualities of the foetus, and that, as these qualities are in part derived to the foetus from the male progenitor, the peculiarities of the latter are thereby so ingrafted on the system of the female as to be communicable by her to any offspring she may subsequently have by other males."
In support of this view, Mr. McGillivray cites a case in which there was presented unmistakable evidence that the organization of the placenta admits the return of the venous blood to the mother; and Dr.
Harvey, with much force, suggests that the effect produced is a.n.a.logous to the known fact that const.i.tutional syphilis has been communicated to a female who never had any of the primary symptoms.
Regarding the occurrence of such phenomena, Dr. Harvey under a later date says: "since then I have learned that many among the agricultural body in this district are familiar to a degree that is annoying to them with the facts then adduced in ill.u.s.tration of it, finding that after breeding crosses, their cows though served with bulls of their own breed yield crosses still or rather mongrels; that they were already impressed with the idea of contamination of blood as the cause of the phenomenon; that the doctrine so intuitively commended itself to their minds as soon as stated, that they fancied they were told nothing but what they knew before, so just is the observation that truth proposed is much more easily perceived than without such proposal is it discovered."[12]
Dr. Carpenter, speaking of phenomena a.n.a.logous to what are here alluded to, says:
"Some of these cases appear referable to the strong impression left by the first male parent upon the female; but there are others which seem to render it more likely that the blood of the female has imbibed from that of the foetus, through the placental circulation, some of the attributes which the latter has derived from its male parent, and that the female may communicate these, with those proper to herself, to the subsequent offspring of a different male parentage. This idea is borne out by a great number of important facts. * * As this is a point of great practical importance it may be hoped that those who have the opportunity of bringing observation to bear upon it, will not omit to do so."
In the absence of more general and accurate observations directed to this point, it is impossible to say to what extent the first male produces impression upon subsequent progeny by other males. There can be no doubt, however, but that such an impression is made. The instances where it is of so marked and obvious a character as in some of those just related may be comparatively few, yet there is abundant reason to believe, that although in a majority of cases the effect may be less noticeable, it is not less real, and demands the special attention of all breeders.
Whether this result is to be ascribed to inoculation of the system of the female with the characteristics of the male through the foetus, or to any other mode of operation, it is obviously of great advantage for every breeder to know it and thereby both avoid error and loss and secure profit. It is a matter which deserves thorough investigation and the observations should be minute and have regard not only to peculiarities of form, but also to qualities and characteristics not so obvious; for instance there may be greater or less hardiness, endurance or apt.i.tude to fatten. These may be usually more dependent on the dam, but the male is never without a degree of influence upon them, and it is well established that apt.i.tude to fatten is usually communicated by the Short-horn bull to crosses with cattle of mixed or mongrel origin which are often very deficient in this desirable property.
Mr. McGillivray says: "A knowledge of the fact must be of the greatest benefit to the breeder in two ways, positively and negatively. I have known very great disappointment and loss result from allowing an inferior male to serve a first rate female--the usefulness of such female being thereby forever destroyed. As for the positive benefits arising from the inoculation--they are obvious to any unbiased mind.
The black polled and Aberdeens.h.i.+re cattle common to this country (Scotland) may be, and often are, improved by the following plan: Select a good, well formed, and healthy heifer--put her, in proper season, to a pure Short-horn bull; after the calf to this Durham bull, breed from the cow with bulls of her own breed; occasionally, and most likely the first time, a red calf ultimately having horns will appear even from the polled bull and cow; but in general the calves will be of the same type with the polled parents but with many points improved, and an apt.i.tude to fatten, to come earlier to maturity, &c., such as no one of the pure polled or Aberdeens.h.i.+re breed ever exhibited in this country, or any other country, however well kept, previous to the introduction of the Short-horn breed. The offspring of these breeds thus improved, when bred from again, will exhibit many points and qualities of excellence similar to the best crosses but retaining much of the hardiness of the original stock, no mean consideration for this changeable and often severe climate. And, moreover, such crosses,--for they are crosses--will command high prices as improved polled or Aberdeens.h.i.+re cattle. I happen to know of a case where a farmer, from a distance purchased a two year old heifer of the stamp referred to, for the purpose of improving his polled cattle, and for this heifer he paid fifty guineas."
The knowledge of this law[13] gives us a clue to the cause of many of the disappointments of which practical breeders often complain and to the cause of many variations otherwise unaccountable, and it suggests particular caution as to the first male employed in the coupling of animals, a matter which has often been deemed of little consequence in regard to cattle, inasmuch as fewer heifers' first calves are reared, than of such as are borne subsequently.
Another faint ray of light touching the causes of variation is afforded us by the fact that the qualities of offspring are not only dependent on the habitual conditions of the parents, but also upon any peculiar condition existing at the time of s.e.xual congress. For instance, the offspring of parents ordinarily healthy and temperate, but begotten in a fit of intoxication, would be likely to suffer permanently, both physically and mentally, from the condition which the parents had temporarily brought upon themselves. On the other hand, offspring begotten of parents in an unusually healthy and active condition of body and mind, would likely be unusually endowed both mentally and physically. The Arabs in breeding horses take advantage of this fact, for before intercourse, both sire and dam are actively exercised, not to weariness, but sufficiently to induce the most vigorous condition possible. Of this, too, we have proof in the phenomenon sometimes observed by breeders, that a strong mental impression made upon the female by a particular male, will give the offspring a resemblance to him, even though she have no s.e.xual intercourse with him. Of this, Mr. Boswell in his prize essay published in 1828, gives a remarkable instance. He says that Mr.
Mustard of Angus, one of the most intelligent breeders he had ever met with, told him that one of his cows chanced to come into season while pasturing on a field bounded by that of one of his neighbors, out of which field an ox jumped and went with the cow until she was brought home to the bull. The ox was white, with black spots, and horned. Mr.
Mustard had not a horned beast in his possession, nor one with any white on it. Nevertheless, the produce of the following spring was a black and white calf with horns.
The case of Jacob is often quoted in support of this view, and although many believe some miraculous agency to have been exerted in his case, and though he could say with truth, "G.o.d hath taken away the cattle of your father and given them to me," it seems, on the whole, more probable, inasmuch as supernatural agency may never be presumed, except where we know, or have good reason to believe, that natural causes are insufficient, that G.o.d "gave" them, as he now gives to some, riches or honors; that is to say, by virtue of the operation of natural laws. If all who keep cattle would exercise a t.i.the of the patriarch's shrewdness and sagacity in improving their stock, we should see fewer ill-favored kine than at present.
The possibility of some effect being produced by a strong impression at the time of conception, is not to be confounded with the popular error that "marks" upon an infant[14] are due to a transient, although strong impression upon the imagination of the mother at any period of gestation, which is unsupported by facts and absurd; but there are facts sufficient upon record to prove that _habitual_ mental condition, and especially at an early stage of pregnancy, _may_ have the effect to produce some bodily deformity, and should induce great caution.
FOOTNOTES:
[3] See Rowley's Prize Report on Farming in Derbys.h.i.+re, in Journal of Royal Agricultural Society, Vol. 14.
[4] A _working bull_, though perhaps not so pleasing to the eye as a fat one, (for fat sometimes covers a mult.i.tude of defects,) is a surer stock-getter; and his progeny is more likely to inherit full health and vigor.
The Principles of Breeding Part 2
You're reading novel The Principles of Breeding Part 2 online at LightNovelFree.com. You can use the follow function to bookmark your favorite novel ( Only for registered users ). If you find any errors ( broken links, can't load photos, etc.. ), Please let us know so we can fix it as soon as possible. And when you start a conversation or debate about a certain topic with other people, please do not offend them just because you don't like their opinions.
The Principles of Breeding Part 2 summary
You're reading The Principles of Breeding Part 2. This novel has been translated by Updating. Author: S. L. Goodale already has 712 views.
It's great if you read and follow any novel on our website. We promise you that we'll bring you the latest, hottest novel everyday and FREE.
LightNovelFree.com is a most smartest website for reading novel online, it can automatic resize images to fit your pc screen, even on your mobile. Experience now by using your smartphone and access to LightNovelFree.com
- Related chapter:
- The Principles of Breeding Part 1
- The Principles of Breeding Part 3