Sheep, Swine, and Poultry Part 3

GENUS. _Oris_--the sheep family.

Of this _Genus_ there are three varieties: ORIS, AMMON, or ARGALI.

_Oris Musmon._ _Oris Aries_, or Domestic Sheep.

Of the latter--with which alone this treatise is concerned--there are about forty well known varieties. Between the _oris_, or sheep, and the _capra_, or goat, another _genus_ of the same family, the distinctions are well marked, although considerable resemblance exists between them.

The horns of the sheep have a spiral direction, while those of the goat have a direction upward and backward; the sheep, except in a single wild variety, has no beard, while the goat is bearded; the goat, in his highest state of improvement, when he is made to produce wool of a fineness unequalled by the sheep--as in the Cashmere breed--is mainly, and always, externally covered with hair, while the hair on the sheep may, by domestication, be reduced to a few coa.r.s.e hairs, or got rid of altogether; and, finally, the pelt or skin of the goat has thickness very far exceeding that of the sheep.

The age of sheep is usually reckoned, not from the time that they are dropped, but from the first shearing; although the first year may thus include fifteen or sixteen months, and sometimes more. When doubt exists relative to the age, recourse is had to the teeth, since there is more uncertainty about the horn in this animal than in cattle; ewes that have been early bred, appearing always, according to the rings on the horn, a year older than others that have been longer kept from the ram.

FORMATION OF THE TEETH.

Sheep have no teeth in the upper jaw, but the bars or ridges of the palate thicken as they approach the forepart of the mouth; there also the dense, fibrous, elastic matter, of which they are const.i.tuted, becomes condensed, and forms a cus.h.i.+on or bed, which covers the converse extremity of the upper jaw, and occupies the place of the upper incisor, or cutting teeth, and partially discharge their functions. The herbage is firmly held between the front teeth in the lower jaw and this pad, and thus partly bitten and partly torn asunder. Of this, the rolling motion of the head is sufficient proof.

The teeth are the same in number as in the mouth of the ox. There are eight incisors or cutting-teeth in the forepart of the lower jaw, and six molars in each jaw above and below, and on either side. The incisors are more admirably formed for grazing than in the ox. The sheep lives closer, and is destined to follow the ox, and gather nourishment where that animal would be unable to crop a single blade. This close life not only loosens the roots of the gra.s.s, and disposes them to spread, but by cutting off the short suckers and sproutings--a wise provision of nature--causes the plants to throw out fresh, and more numerous, and stronger ones, and thus is instrumental in improving and increasing the value of the crop. Nothing will more expeditiously and more effectually make a thick, permanent pasture than its being occasionally and closely eaten down by sheep.

In order to enable the sheep to bite this close, the upper lip is deeply divided, and free from hair about the centre of it. The part of the tooth above the gum is not only, as in other animals, covered with enamel, to enable it to bear and to preserve a sharpened edge, but the enamel on the upper part rises from the bone of the tooth nearly a quarter of an inch, and presenting a convex surface outward, and a concave within, forms a little scoop or gorge of wonderful execution.

The mouth of the lamb newly dropped is either without incisor teeth or it has two. The teeth rapidly succeed to each other, and before the animal is a month old he has the whole of the eight. They continue to grow with his growth until he is about fourteen or sixteen months old.

Then, with the same previous process of diminution as in cattle, or carried to a still greater degree, the two central teeth are shed, and attain their full growth when the sheep is two years old.

In examining a flock of sheep, however, there will often be very considerable difference in the teeth of those that have not been sheared, or those that have been once sheared; in some measure to be accounted for by a difference in the time of lambing, and likewise by the general health and vigor of the animal. There will also be a material difference in different animals, attributable to the good or bad keep which they have had. Those fed on good land, or otherwise well kept, will generally take the start of others that have been half starved, and renew their teeth some months sooner than these. There are also irregularities in the times of renewing the teeth, not to be accounted for by either of these circ.u.mstances; in fact, not to be explained by any known circ.u.mstance relating to the breed or the keep of the sheep. The want of improvement in sheep, which is occasionally observed, and which cannot be accounted for by any deficiency or change of food, may sometimes be justly attributed to the tenderness of the mouth when the permanent teeth are protruding through the gums.

Between two and three years old the next two incisors are shed; and when the sheep is actually three years old, the four central teeth are fully grown; at four years old, he has six teeth fully grown; and at five years old--one year before the horse or the ox can be said to be full-mouthed--all the teeth are perfectly developed. The sheep is a much shorter-lived animal than the horse, and does not often attain the usual age of the ox. Their natural age is about ten years, to which age they will breed and thrive well; though there are recorded instances of their breeding at the age of fifteen, and of living twenty years.

The careless examiner may be sometimes deceived with regard to the four-year-old mouth. He will see the teeth perfectly developed, no diminutive ones at the sides, and the mouth apparently full; and then, without giving himself the trouble of counting the teeth, he will conclude that the animal is five years old. A process of displacement, as well as of diminution, has taken place here; the remaining outside milk-teeth have not only shrunk to less than a fourth part of their original size, but the four-year-old teeth have grown before them and perfectly conceal them, unless the mouth is completely opened.

After the permanent teeth have all appeared and are fully grown, there is no criterion as to the age of the sheep. In most cases, the teeth remain sound for one or two years, and then, at uncertain intervals--either on account of the hard work in which they have been employed, or from the natural effect of age--they begin to loosen and fall out; or, by reason of their natural slenderness, they are broken off. When favorite ewes, that have been kept for breeding, begin to lose condition, at six or seven years old, their mouths should be carefully examined. If any of the teeth are loose, they should be extracted, and a chance given to the animal to show how far, by browsing early and late, she may be able to make up for the diminished number of her incisors. It frequently happens that ewes with broken teeth, and some with all the incisors gone, will keep pace in condition with the best in the flock; but they must be well taken care of in the winter, and, indeed, nursed to an extent that would scarcely answer the farmer's purpose to adopt as a general rule, in order to prevent them from declining to such a degree as would make it very difficult afterward to fatten them for the butcher. It may certainly be taken as a general rule, that when sheep become broken-mouthed they begin to decline.

Causes of which the farmer is utterly ignorant, or over which he has no control, will sometimes hasten the loss of the teeth. One thing, however, is certain--that close feeding, causing additional exercise, does wear them down; and that the sheep of farmers who stock unusually and unseasonably hard, lose their teeth much sooner than others do.

THE STRUCTURE OF THE SKIN.

The skin of the sheep, in common with that of most animals, is composed of three textures. Externally is the cuticle, or scarf-skin, which is thin, tough, devoid of feeling, and pierced by innumerable minute holes, through which pa.s.s the fibres of the wool and the insensible perspiration. It seems to be of a scaly texture; although is not so evident as in many other animals, on account of a peculiar substance--the yolk--which is placed on it, to protect and nourish the roots of the wool. It is, however, sufficiently evident in the scab and other cutaneous eruptions to which this animal is liable.

Below this cuticle is the _rete mucosum_, a soft structure; its fibres having scarcely more consistence than mucilage, and being with great difficulty separated from the skin beneath. This appears to be placed as a defence to the terminations of the blood-vessels and nerves of the skin, which latter are, in a manner, enveloped and covered by it. The color of the skin, and probably that of the hair or wool also, is determined by the _rete mucosum_; or, at least, the hair and wool are of the same color as this substance.

Beneath the _rete mucosum_ is the _cutis_, or true skin, composed of numberless minute fibres crossing each other in every direction; highly elastic, in order to fit closely to the parts beneath, and to yield to the various motions of the body; and dense and firm in its structure, that it may resist external injury. Blood-vessels and nerves innumerable pierce it, and appear on its surface in the form of _papillae_, or minute eminences; while, through thousands of little orifices, the exhalent absorbents pour out the superfluous or redundant fluid. The true skin is composed, princ.i.p.ally or almost entirely, of gelatine; so that, although it may be dissolved by long-continued boiling, it is insoluble in water at the common temperature. This organization seems to have been given to it, not only for the sake of its preservation while on the living animal, but that it may afterwards become useful to man.

The substance of the hide readily combining with the tanning principle, is converted into leather.

THE ANATOMY OF THE WOOL.

[Ill.u.s.tration: THE WALLACHIAN SHEEP.]

On the skin of most animals is placed a covering of feathers, fur, hair, or wool. These are all essentially the same in composition, being composed of an animal substance resembling coagulated alb.u.men, together with sulphur, silica, carbonate and phosphate of lime, and oxides of iron and manganese.

Wool is not confined to the sheep. The under-hair of some goats is not only finer than the fleece of any sheep, but it occasionally has the crisped appearance of wool; being, in fact, wool of different qualities in different breeds--in some, rivalling or excelling that of the sheep, but in others very coa.r.s.e. A portion of wool is also found on many other animals; as the deer, elk, the oxen of Tartary and Hudson's Bay, the gnu, the camel, many of the fur-clad animals, the sable, the polecat, and several species of the dog.

Judging from the mixture of wool and hair in the coat of most animals, and the relative situation of these materials, it is not improbable that such was the character of the fleece of the primitive sheep. It has, indeed, been a.s.serted that the primitive sheep was entirely covered with hair; but this is, doubtless, incorrect. There exists, at the present day, varieties of the sheep occupying extensive districts, that are clothed outwardly with hair of different degrees of fineness and sleekness; and underneath the external coat is a softer, shorter, and closer one, that answers to the description of fur--according to most travellers--but which really possesses all the characteristics of wool.

It is, therefore, highly improbable that the sheep--which has now become, by cultivation, the wool-bearing animal in a pre-eminent degree--should, in any country, at any time, have ever been entirely dest.i.tute of wool. Sheep of almost every variety have at times been in the gardens of the London (Eng.) Zoological Society; but there has not been one on which a portion of crisped wool, although exceedingly small, has not been discovered beneath the hair. In all the regions over which the patriarchs wandered, and extending northward through the greater part of Europe and Asia, the sheep is externally covered with hair; but underneath is a fine, short, downy wool, from which the hair is easily separated. This is the case with the sheep at the Cape of Good Hope, and also in South America.

The change from hair to wool, though much influenced by temperature, has been chiefly effected by cultivation. Wherever hairy sheep are now found the management of the animal is in a most disgraceful state; and among the cultivated sheep the remains of this ancient hairy covering only exists, to any great extent, among those that are comparatively neglected or abandoned.

The filament of the wool has scarcely pushed itself through the pore of the skin, when it has to penetrate through another and singular substance, which, from its adhesiveness and color, is called _the yolk_.

This is found in greatest quant.i.ty about the breast and shoulders--the very parts that produce the best, and healthiest, and most abundant wool--and in proportion as it extends, in any considerable degree, over other parts, the wool is then improved. It differs in quant.i.ty in different breeds. It is very abundant on the Merinos; it is sufficiently plentiful on most of the southern breeds, either to a.s.sist in the production of the wool, or to defend the sheep from the inclemency of the weather; but in the northern districts, where the cold is more intense and the yolk of wool is deficient, a subst.i.tute for it is sometimes sought by smearing the sheep with a mixture of tar, oil, or b.u.t.ter. Where there is a deficiency of yolk, the fibre of the wool is dry, harsh, and weak, and the whole fleece becomes thin and hairy; where the natural quant.i.ty of it is found, the wool is soft, oily, plentiful and strong.

This yolk is not the insp.i.s.sated or thickened perspiration of the animal; it is not composed of matter which has been accidentally picked up, and which has lodged in the wool; but it is a peculiar secretion from the glands of the skin, destined to be one of the agents in the nourishment of the wool, and at the same time, by its adhesiveness, to mat the wool together, and form a secure defence from the wet and cold.

Chemical experiments have established its composition, as follows: first, of a soapy matter with a basis of potash, which forms the greater part of it; second, a small quant.i.ty of carbonate of potash; third, a perceptible quant.i.ty of acetate of potash; fourth, lime, in a peculiar and unknown state of combination; fifth, an atom of muriate of potash; sixth, an animal oil, to which its peculiar odor is attributable. All these materials are believed to be essential to the yolk, and not found in it by mere accident, since the yolk of a great number of samples--Spanish, French, English, and American--has been subjected to repeated a.n.a.lyses, with the same result.

The yolk being a true soap, soluble in water, it is not difficult to account for the comparative ease with which sheep that have the natural proportion of it are washed in a running stream. There is, however, a small quant.i.ty of fatty matter in the fleece, which is not in combination with the alkali, and which, remaining attached to the wool, keeps it a little glutinous, notwithstanding the most careful was.h.i.+ng.

The fibre of the wool having penetrated the skin and escaped from the yolk, is of a circular form, generally larger toward the extremity, and also toward the root, and in some instances very considerably so. The filaments of white wool, when cleansed from grease, are semi-transparent; their surface in some places is beautifully polished, in others curiously incrusted, and they reflect the rays of light in a very pleasing manner. When viewed by the aid of a powerful achromatic microscope, the central part of the fibre has a singularly glittering appearance. Minute filaments, placed very regularly, are sometimes seen branching from the main trunk, like boughs from the princ.i.p.al stem. This exterior polish varies much in different wools, and in wools from the same breed of sheep at different times. When the animal is in good condition, and the fleece healthy, the appearance of the fibre is really brilliant; but when the state of the const.i.tution is bad, the fibre has a dull appearance, and either a wan, pale light, or sometimes scarcely any, is reflected. As a general rule, the filament is most transparent in the best and most useful wools, whether long or short. It increases with the improvement of the breed, and the fineness and healthiness of the fleece; yet it must be admitted that some wools have different degrees of the transparency and opacity, which do not appear to affect their value and utility. It is, however, the difference of transparency in the same fleece, or in the same filament, that is chiefly to be noticed as improving the value of the wool.

As to the size of the fibre, the terms "fine" and "coa.r.s.e," as commonly used, are but vague and general descriptions of wool. All fine fleeces have some coa.r.s.e wool, and all coa.r.s.e fleeces some fine. The most accurate cla.s.sification is to distinguish the various qualities of wool in the order in which they are esteemed and preferred by the manufacturer--as the following: first, fineness with close ground, that is, thick-matted ground; second, pureness; third, straight-haired, when broken by drawing; fourth, elasticity, rising after compression in the hand; fifth, staple not too long; sixth, color; seventh, what coa.r.s.e exists to be very coa.r.s.e; eighth, tenacity; and ninth, not much pitch-mark, though this is no disadvantage, except the loss of weight in scouring. The bad or disagreeable properties are--thin, grounded, tossy, curly-haired, and, if in a sorted state, little in it that is very fine; a tender staple, as elasticity, many dead white hairs, very yolky. Those who buy wool for combing and other light goods that do not need milling, wish to find length of staple, fineness of hair, whiteness, tenacity, pureness, elasticity, and not too many pitch-marks.

The property first attracting attention, and being of greater importance than any other, is _the fineness_ of the pile--the quant.i.ty of fine wool which a fleece yields, and the degree of that fineness. Of the absolute fineness, little can be said, varying, as it does, in different parts of the same fleece to a very considerable degree, and the diameter of the same fibre often being exceedingly different at the extremity and the centre. The micrometer has sometimes indicated that the diameter of the former is five times as much as that of the latter; and, consequently, that a given length of yield taken from the extremity would weigh twenty-five times as much as the same length taken from the centre and cleansed from all yolk and grease. That fibre may be considered as coa.r.s.e whose diameter is more than the five-hundredth part of an inch; in some of the most valuable samples of Saxony wool it has not exceeded the nine-hundredth part; yet in some animals, whose wool has not been used for manufacturing purposes, it is less than one twelve-hundredth part.

The extremities of the wool, and frequently those portions which are near to the root, are larger than the intermediate parts. The extremity of the fibre has, generally, the greatest bulk of all. It is the product of summer, soon after shearing-time, when the secretion of the matter of the wool is increased, and when the pores of the skin are relaxed and open, and permit a larger fibre to protrude. The portion near the root is the growth of spring, when the weather is getting warm; and the intermediate part is the offspring of winter, when under the influence of the cold the pores of the skin contract, and permit only a finer hair to escape. If, however, the animal is well fed, the diminution of the bulk of the fibre will not be followed by weakness or decay, but, in proportion as the pile becomes fine, the value of the fleece will be increased; whereas, if cold and starvation should go hand-in-hand, the woolly fibre will not only diminish in bulk, but in health, strength, and worth.

The variations in the diameter of the wool in different parts of the fibre will also curiously correspond with the degree of heat at the time the respective portions were produced. The fibre of the wool and the record of the meteorologist will singularly agree, if the variations in temperature are sufficiently distinct from each other for any appreciable part of the fibre to form. It follows from this, that--the natural tendency to produce wool of a certain fibre being the same--sheep in a hot climate will yield a comparatively coa.r.s.e wool, and those in a cold climate will carry a finer, but at the same time a closer and a warmer fleece. In proportion to the coa.r.s.eness of a fleece will generally be its openness, and its inability to resist either cold or wet; while the coat of softer, smaller, more pliable wool will admit of no interstices between its fibres, and will bid defiance to frost and storms.

The natural instinct of the sheep would seem to teach the wool-grower the advantage of attending to the influence of temperature upon the animal. He is evidently impatient of heat. In the open districts, and where no shelter is near, he climbs to the highest parts of his walk, that, if the rays of the sun must still fall on him, he may nevertheless be cooled by the breeze; but, if shelter is near, of whatever kind, every shaded spot is crowded with sheep. The wool of the Merinos after shearing-time is hard and coa.r.s.e to such a degree as to render it very difficult to suppose that the same animal could bear wool so opposite in quality, compared with that which had been clipped from it in the course of the same season. As the cold weather advances, the fleeces recover their soft quality.

Pasture has a far greater influence on the fineness of the fleece. The staple of the wool, like every other part of the sheep, must increase in length or in bulk when the animal has a superabundance of nutriment; and, on the other hand, the secretion which forms the wool must decrease like every other, when sufficient nourishment is not afforded. When little cold has been experienced in the winter, and vegetation has scarcely been checked, the sheep yields an abundant crop of wool, but the fleece is perceptibly coa.r.s.er as well as heavier. When the frost has been severe, and the ground long covered with snow, if the flock has been fairly supplied with nutriment, although the fleece may have lost a little in weight, it will have acquired a superior degree of fineness, and a proportional increase of value. Should, however, the sheep have been neglected and starved during this continued cold weather, the fleece as well as the carca.s.s is thinner, and although it may have preserved its smallness of filament, it has lost in weight, and strength, and usefulness.

Connected with fineness is _trueness of staple_--as equal in growth as possible over the animals--a freedom from those s.h.a.ggy portions, here and there, which are occasionally observed on poor and neglected sheep.

These portions are always coa.r.s.e and comparatively worthless, and they indicate an irregular and unhealthy action of the secretion of wool, which will also probably weaken or render the fibre diseased in other parts. Included in trueness of fibre is another circ.u.mstance to which allusion has already been made--a freedom from coa.r.s.e hairs which project above the general level of the wool in various parts, or, if they are not externally seen, mingle with the wool and debase its qualities.

_Soundness_ is closely a.s.sociated with trueness. It means, generally speaking, strength of the fibre, and also a freedom from those breaches or withered portions of which something has previously been said. The eye will readily detect the breaches; but the hair generally may not possess a degree of strength proportioned to its bulk. This is ascertained by drawing a few hairs out of the staple, and grasping each of them singly by both ends, and pulling them until they break. The wool often becomes injured by felting while it is on the sheep's back. This is princ.i.p.ally seen in the heavy breeds, especially those that are neglected and half-starved, and generally begins in the winter season, when the coat has been completely saturated with water, and it increases until shearing-time, unless the cob separates from the wool beneath, and drops off.

Wool is generally injured by keeping. It will probably increase a little in weight for a few months, especially if kept in a damp place; but after that it will somewhat rapidly become lighter, until a very considerable loss will often be sustained. This, however, is not the moral of the case; for, except very great care is taken, the moth will get into the bundles and injure and destroy the staple; and that which remains untouched by them will become considerably harsh and less pliable. If to this the loss of the interest of money is added, it will be seen that he seldom acts wisely who h.o.a.rds his wool, when he can obtain what approaches to a fair remunerating price for it.

_Softness_ of the wool is evidently connected with the presence and quality of the yolk. This substance is undoubtedly designed not only to nourish the hair, but to give it richness and pliability. The growth of the yolk ought to be promoted, and agriculturists ought to pay more attention to the quant.i.ty and quality of yolk possessed by the animals selected for the purpose of breeding.

Bad management impairs the pliability of the wool, by arresting the secretion of the yolk. The softness of the wool is also much influenced by the chemical elements of the soil. A chalky soil notoriously deteriorates it; minute particles of the chalk being necessarily brought into contact with the fleece and mixing with it, have a corrosive effect on the fibre, and harden it and render it less pliable. The particles of chalk come in contact with the yolk--there being a chemical affinity between the alkali and the oily matter of the yolk--immediately unite, and a true soap is formed. The first storm washes a portion of it; and the wool, deprived of its natural pabulum and unguent, loses some of its vital properties--its pliability among the rest. The slight degree of harshness which has been attributed to the English South-Down has been explained in this way.

_The felting property_ of wool is a tendency of the fibres to entangle themselves together, and to form a ma.s.s more or less difficult to unravel. By moisture and pressure, the fibres of the wool may become matted or felted together into a species of cloth. The manufacture of felt was the first mode in which wool was applied to clothing, and felt has long been in universal use for hats. The fulling of flannels and broadcloths is effected by the felting principle. By the joint influence of the moisture and the pressure, certain of the fibres are brought into more intimate contact with each other; they adhere--not only the fibres, but; in a manner, the threads--and the cloth is taken from the mill shortened in all its dimensions; it has become a kind of felt, for the threads have disappeared, and it can be cut in every direction with very little or no unravelling; it is altogether a thicker, warmer, softer fibre. This felting property is one of the most valuable qualities possessed by wool, and on this property are the finer kinds of wool especially valued by the manufacturer for the finest broadcloths. This naturally suggests a consideration of the various forms in the structure on which it depends.

The most evident distinction between the qualities of hair and wool is the comparative straightness of the former, and _the crisped or spirally-curling form_ which the latter a.s.sumes. If a little lock of wool is held up to the light, every fibre of it is twisted into numerous minute corkscrew-like ringlets. This is especially seen in the fleece of the short-woolled sheeps; but, although less striking, it is obvious even in wool of the largest staple.

The spirally-curving form of wool used, erroneously, to be considered as the chief distinction between the covering of the goat and the sheep; but the under-coat of some of the former is finer than that of any sheep, and it is now acknowledged frequently to have the crisped and curled appearance of wool. In some breeds of cattle, particularly in one variety of the Devons, the hair a.s.sumes a curled and wavy appearance, and a few of the minute spiral ringlets have been occasionally seen. It is the same with many of the Highlands; but there is no determination to take on the true crisped character, and throughout its whole extent, and it is still nothing but hair. On some foreign breeds, however, as the yak of Tartary, and the ox of Hudson's Bay, some fine and valuable wool is produced.

There is an intimate connection between the fineness of the wool and the number of the curves, at least in sheep yielding wool of nearly the same length; so that, whether the wool of different sheep is examined, or that from different parts of the same sheep, it is enough for the observer to take advice of the number of curves in a given s.p.a.ce, in order to ascertain with sufficient accuracy the fineness of the fibre.

To this curled form of the wool not enough attention is, as a general thing, paid by the breeder. It is, however, that on which its most valuable uses depend. It is that which is essential to it in the manufactory of cloths. The object of the carder is to break the wool in pieces at the curves--the principle of the thread is the adhesion of the particles together by their curves; and the fineness of the thread, and consequent fineness of the cloth, will depend on the minuteness of these curves, or the number of them found in a given length of fibre.

It will readily be seen that this curling form has much to do with the felting property of wool; it materially contributes to that disposition in the fibres which enables them to attach and intwine themselves together; it multiplies the opportunities for this interlacing, and it increases the difficulty of unravelling the felt.