CROSSING.
The practice of crossing, like that of close breeding, has its strong
and its weak side. Substantial arguments can be brought both in its
favor and against it. Judiciously practiced, it offers a means of
procuring animals _for the butcher_, often superior to and more
profitable than those of any pure breed. It is also admissible as the
foundation of a systematic and well considered attempt to establish a
new breed. Such attempts, however, as they necessarily involve
considerable expense, and efforts continued during a long term of
years, will be rarely made. But when crossing is practiced
injudiciously and indiscriminately, and especially when so done for
the purpose of procuring _breeding animals_, it cannot be too severely
censured, and is scarcely less objectionable than careless in-and-in
breeding.
The following remarks, from the pen of W.C. Spooner, V.S., are
introduced as sound and reliable, and as comprising nearly all which
need be said on the subject of crossing breeds possessing distinctive
characteristics:
"Crossing is generally understood to refer to the alliance of
animals of different breeds, such as between a thorough-bred and
a half-bred among horses or a South Down and Leicester among
sheep. Now the advantages or disadvantages of this system depend
entirely on the object we have in view, whether merely to beget
an animal for the butcher, or for the purpose of perpetuating
the species. If the latter is the object, then crossing should
be adopted gradually and with care, and by no means between
distant or antagonistic qualities, as for example a
thorough-bred and a cart-horse. The result of the latter
connection is generally an ill-assorted and unfavorable animal,
too heavy perhaps for one purpose, and too light for another. If
we wish to instil more activity into the cart-horse breed, it is
better to do so by means of some half-bred animal, whilst the
latter can be improved by means of the three-parts-bred horse
and this again by the thorough-bred. There is a remarkable
tendency, in breeding, for both good qualities and bad to
disappear for one or two generations, and to reappear in the
second and third; thus an animal often resembles the grand dam
more than the dam. This peculiarity is itself an objection to
the practice of crossing, as it tends to prevent uniformity and
to encourage contrarieties; and thus we find in many flocks and
herds that the hopes of the breeders have been entirely baffled
and a race of mongrels established.
The first cross is generally successful--a tolerable degree of
uniformity is produced, resembling in external conformation the
sire, which is usually of a superior breed; and thus the
offspring are superior to the dams. These cross-bred animals are
now paired amongst each other, and what is the consequence?
Uniformity at once disappears; some of the offspring resemble
the grandsire, and others the grandams, and some possess the
disposition and constitution of the one and some of the other;
and consequently a race of mongrels is perpetuated. If, however,
the cross is really a good and desirable one, then, by means of
rigorous and continued selection, pursued for several
generations, that is, by casting aside, as regards breeding
purposes, every animal that does not exhibit uniformity, or
possess the qualifications we are desirous of perpetuating, a
valuable breed of animals may in the course of time be
established. By this system many varieties of sheep have been so
far improved as to become almost new breeds; as for instance the
New Oxford Downs which have frequently gained prizes at the
great Agricultural Meetings as being the best long wooled sheep.
To cross, however, merely for crossing sake--to do so without
that care and vigilance which we have deemed so essential--is a
practice which cannot be too much condemned. It is in fact a
national evil and a sin against society, that is, if carried
beyond the first cross, or if the cross-bred animals are used
for breeding. A useful breed of animals may thus be lost, and a
generation of mongrels established in their place, a result
which has followed in numerous instances amongst every breed of
animals.
The principal use of crossing, however, is to raise animals for
the butcher. In this respect it has not (with sheep) been
adopted to the extent which it might to advantage. The male
being generally an animal of a superior breed and of a vigorous
nature, almost invariably stamps his external form, size and
muscular development on the offspring, which thus bear a strong
resemblance to him, whilst their internal nature derived from
the dam, well adapts them to the locality, as well as to the
treatment to which their dams have been accustomed.
With regard to cattle, the system cannot be so advantageously
pursued (except for the purpose of improving the size and
qualities of the calf, where veal is the object) in as much as
every required qualification for breeding purposes can be
obtained by using animals of the pure breeds. But with sheep,
where the peculiarities of the soil as regards the goodness of
feed, and exposure to the severities of the weather, often
prevent the introduction of an improved breed, the value of
using a new and superior ram is often very considerable, and the
weight of mutton is materially increased, without its quality
being impaired, while earlier maturity is at the same time
obtained. It involves, however, more systematic attention than
farmers usually like to bestow, for it is necessary to employ a
different ram for each purpose; that is, a native ram for a
portion of the ewes to keep up the purity of the breed, and a
foreign ram to raise the improved cross-bred animals for fatting
either as lambs or sheep. This plan is adopted by many breeders
of Leicester sheep, who thus employ South Down rams to improve
the quality of the mutton. One inconvenience attending this
plan, is the necessity of fatting the maiden ewes as well as the
wethers; they may however be disposed of as fat lambs, or the
practice of spaying might be adopted, so as to increase the
fatting disposition of the animal. Crossing, therefore, should
be adopted with the greatest caution and skill where the object
is to improve the breed of animals; it should never be practiced
carelessly or capriciously, but it may be advantageously pursued
with a view to raising superior and profitable animals for the
butcher."
In another paper on this subject, after presenting many interesting
details regarding British breeds of sheep and the results of crossing,
Mr. Spooner says:
"We cannot do better, in concluding our paper, than gather up
and arrange in a collected form, the various points of our
subject, which appear to be of sufficient importance to be again
presented to the attention of our readers. We think, therefore,
we are justified in coming to the conclusions:
1st. That there is a direct pecuniary advantage in judicious
cross-breeding; that increased size, disposition to fatten, and
early maturity, are thereby induced.
2d. That while this may be caused for the most part, by the very
fact of crossing, yet it is principally due to the superior
influence of the male over the size and external appearance of
the offspring; so that it is desirable, for the purpose of the
butcher, that the male should be of a larger frame than the
female, and should excel in those peculiarities we are desirous
of reproducing. Let it be here however, repeated, as an
exceptional truth, that though as a rule the male parent
influences mostly the size and external form, and the female
parent the constitution, general health and vital powers, yet
that the opposite result sometimes takes place.
3d. Certain peculiarities may be imparted to a breed by a single
cross. Thus, the ponies of the New Forest exhibit
characteristics of blood, although it is many years since that a
thorough-bred horse was turned into the forest for the purpose.
So, likewise, we observe in the Hampshire sheep the Roman nose
and large heads, which formed so strong a feature in their
maternal ancestors, although successive crosses of the South
Down were employed to change the character of the breed. * * *
4th. Although in the crossing of sheep for the purpose of the
butcher, it is generally advisable to use males of a larger
breed, provided they possess a disposition to fatten; yet, in
such cases, it is of importance that the _pelvis_ of the female
should be wide and capacious, so that no injury should arise in
lambing, in consequence of the increased size of the heads of
the lambs. The shape of the ram's head should be studied for the
same reason. In crossing, however, for the purpose of
establishing a new breed, the size of the male must give way to
other more important considerations; although it will still be
desirable to use a large female of the breed which we seek to
improve. Thus the South Downs have vastly improved the larger
Hampshires, and the Leicester the huge Lincolns and the
Cotswolds.
5th. Although the benefits are most evident in the first cross,
after which, from pairing the cross-bred animals, the defects of
one breed or the other, or the incongruities of both, are
perpetually breaking out--yet, unless the characteristics and
conformation of the two breeds are altogether averse to each
other, nature opposes no barrier to their successful admixture;
so that in the course of time, by the aid of selection and
careful weeding, it is practicable to establish a new breed
altogether. This, in fact, has been the history of our principal
breeds. * * *
We confess that we cannot entirely admit either of the
antagonistic doctrines held by the rival advocates of crossing
and pure breeding. The public have reason to be grateful to the
exertions of either party; and still more have they respectively
reason to be grateful to each other. * * * *
Let us conclude by repeating the advice that, when equal
advantages can be attained by keeping a pure breed of sheep,
such pure breed should unquestionably be preferred; and that,
although crossing for the purpose of the butcher may be
practiced with impunity, and even with advantage, yet no one
should do so for the purpose of establishing a new breed, unless
he has clear and well defined views of the object he seeks to
accomplish, and has duly studied the principles on which it can
be carried out, and is determined to bestow for the space of
half a life-time his constant and unremitting attention to the
discovery and removal of defects."
The term crossing is sometimes used in a much more restricted sense,
as in the remark of Mr. Boswell in his essay quoted on page 69 where
he says, "When I praise the advantage of crossing I would have it
clearly understood that it is only to bring together animals _not
nearly related_ but always of _the same breed_." It is evident that
such crossing as this is wholly unobjectionable; no one but an avowed
and ultra advocate of close breeding could possibly find any fault
with it.
There is yet another style of crossing which when practicable, may, it
is believed, be made a means to the highest degree of improvement
attainable, and especially in the breeding of horses. The word "breed"
is often used with varying signification. In order to be understood,
let me premise that I use it here simply to designate a class of
animals possessing a good degree of uniformity growing out of the fact
of a common origin and of their having been reared under similar
conditions. The method proposed is to unite animals _possessing
similarity of desirable characteristics, with difference of breed_;
that is to say, difference of breed in the sense just specified. From
unions based upon this principle, the selections being guided by a
skillful judgment and a discriminating tact, we may expect progeny
possessing not only a fitting and symmetrical development of the
locomotive system, but also an amount and intensity of nervous energy
and power unattainable by any other method.
Such was in all probability the origin of the celebrated horse Justin
Morgan; an animal which not only did more to stamp excellence and
impart value to the roadsters of New England than any other, but was
the originator of the only distinct, indigenous breed of animals of
which America can boast;--a breed which as fast and durable road
horses and for any light harness work, is not equalled by any other,
any where. In the present state of our knowledge it is scarcely
conceivable how an animal possessing the endowments of Justin Morgan
could have originated in any other way than from such a parentage as
above indicated. On the other hand it is very certain that _contrast
in character_, as well as in breed, has occasioned much of the
disappointment of which breeders have had occasion to complain.
The principle here laid down is one of broad application, and should
never be lost sight of in attempts at improvement by crossing. Another
point worthy special attention is that all crossing, to insure
successful results, should be gentle rather than violent; that is,
never couple animals possessing marked dissimilarity, but endeavor to
remedy faults and to effect improvement by gradual approaches. Harmony
of structure and a proper balancing of desirable characteristics, "an
equilibrium of good qualities," as it has been happily expressed, can
be secured only in this way.
It may not be out of place here to say, that much of the talk about
_blood_ in animals, especially horses, is sheer nonsense. When a
"blood horse" is spoken of, it means, so far as it means any thing,
that his pedigree can be traced to Arabian or Barbary origin, and so
is possessed of the peculiar type of structure and great nervous
energy which usually attaches to "thorough-bred" horses. When a bull,
or cow, or sheep is said to be of "pure blood," it means simply that
the animal is of some distinct variety--that it has been bred from an
ancestry all of which were marked by the same peculiarities and
characteristics.
So long as the term "blood" is used to convey the idea of definite
hereditary qualities it may not be objectionable. We frequently use
expressions which are not strictly accurate, as when we speak of the
sun's rising and setting, and so long as every body knows that we
refer to apparent position and not to any motion of the sun, no false
ideas are conveyed. But to suppose that the hereditary qualities of
an animal attach to the blood more than to any other fluid or to any
of the tissues of the body, or that the blood of a high-bred horse is
essentially different from that of another, is entirely erroneous. The
qualities of an animal depend upon its organization and endowments,
and the blood is only the vehicle by which these are nourished and
sustained;--moreover the blood varies in quality, composition and
amount, according to the food eaten, the air breathed and the exercise
taken. If one horse is better than another it is not because the fluid
in his veins is of superior quality, but rather because his structure
is more perfect mechanically, and because nervous energy is present in
fitting amount and intensity.
For illustration, take two horses--one so built and endowed that he
can draw two tons or more, three miles in an hour; the other so that
he can trot a mile in three minutes or less. Let us suppose the blood
coursing in the veins of each to be transferred to the other; would
the draft horse acquire speed thereby, or the trotter acquire power?
Just as much and no more as if you fed each for a month with the hay,
oats and water intended for the other.
It is well to attend to pedigree, for thus only can we know what are
the hereditary qualities, but it is not well to lay too much stress
upon "blood," What matters it that my horse was sired by such a one or
such a one, if he be himself defective? In breeding horses,
_structure_ is first, and endowment with nervous energy is next to be
seen to, and then pedigree--afterwards that these be fittingly united,
by proper selection for coupling, in order to secure the highest
degree of probability which the nature of the case admits, that the
offspring may prove a perfect machine and be suitably endowed with
motive power.
"The body of an animal is a piece of mechanism, the moving power of
which is the vital principle, which like fire to the steam engine sets
the whole in motion; but whatever quantity of fire or vital energy may
be applied, neither the animal machine nor the engine will work with
regularity and effect, unless the individual parts of which the
machine is composed are properly adjusted and fitted for the purposes
for which they are intended; or if it is found that the machine does
move by the increase of moving power, still the motion is irregular
and imperfect; the bolts and joints are continually giving way, there
is a continued straining of the various parts, and the machine becomes
worn out and useless in half the time it might have lasted if the
proportions had been just and accurate. Such is the case with the
animal machine. It is not enough that it is put in motion by the
noblest spirit or that it is nourished by the highest blood; every
bone must have its just proportion; every muscle or tendon its proper
pulley; every lever its proper length and fulcrum; every joint its
most accurate adjustment and proper lubrication; all must have their
relative proportions and strength, before the motions of the machine
can be accurate, vigorous and durable. In every machine modifications
are required according as the purposes vary to which it is applied.
The heavy dray horse is far from having the arrangement necessary for
the purposes of the turf, while the thorough-bred is as ill adapted
for the dray. Animals are therefore to be selected for the individual
purposes for which they are intended, with the modifications of form
proper for the different uses to which they are to be applied; but for
whatever purpose they may be intended, there are some points which are
common to all, in the adjustment of the individual parts. If the bones
want their due proportions, or are imperfectly placed--if the muscles
or tendons want their proper levers--if the flexions of the joints be
interrupted by the defectiveness of their mechanism, the animal must
either be defective in motion or strength; the bones have irregular
pressure, and if they do not break, become diseased; if the muscles or
tendons do not become sprained or ruptured, they are defective in
their action; if friction or inflammation does not take place in the
joints, the motions are awkward and grotesque. As in every other
machine, the beauty of the animate, whether in motion or at rest,
depends upon the arrangement of the individual parts."