Diagrams of the udder of the cow, of the mare and of the ewe : with keys and explanatory notes

Wilkie, Henry C. (Henry Charles), Govt. Printer, Wellington, N.Z., 1904

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Title: Diagrams of the udder of the cow, of the mare and of the ewe : with keys and explanatory notes

Author: Wilkie, Henry C. (Henry Charles)

Published: Govt. Printer, Wellington, N.Z., 1904

DIAGRAMS OF THE UDDER OF THE COW, OF THE MARE, AND OF THE EWE.

WITH KEYS AND EXPLANATORY NOTES

BY HENRY C. WILKIE, E.R.C.Y.S., VKTKUIXAUY DIVISION, DEPARTMENT OF AGHiaiLTURH, NHW ZEALAND,

WELLINGTON

BY AUTHORITY : JOHN MACKAY, GOVERNMENT PRINTER.

4

THE UDDER OF THE COW, OF THE MARE, AND OF THE EWE.

riTHESE drawings were made for the purpose of demonstrating in I a simple and practical manner the more important anatomical features of the udder, or mammary glands, of the cow, of the mare, and of the ewe.

A general knowledge of the structure of these organs, and the uses of their different parts, is not only needed by the declared student of scientific agriculture, but is of the first importance to all who are concerned either in milk-production or the raising of young farm-stock.

The manner of the formation of the milk, the sources of its various constituents, its passage to the milk-cisterns, the provisions made for its retention, and final withdrawal, have been illustrated and described with a view to making plain to all interested such practical facts as are of importance in every-day farm-life.

FIG.' 1. SECTION OF ONE HALF OF THE UDDER OF THE COW.

This drawing shows the structures exhibited by a longitudinal section of one fore and one hind quarter of the udder of the cow, in which the blood-vessels have been filled with an injection of a wax mixture and dissected out to show the directions taken by the larger trunks.

The udder of the cow consists of four quarters and four teats, of which a fore and a hind quarter constitute a lateral half, which has its own fibrous covering, seen at .1. The fore and the hind quarters of each side, although functionally distinct, have no fibrous division between them.

The udder is held in position firstly by several broad suspensory hands which attach it to the abdominal tunic, and secondly by the skin which covers it.

1\ I 11 n it vv/ ■ - ■ The fibrous envelope of the udder consists of yellow elastic tissue, and is continuous with the suspensory bands.

It is in contact with its fellow of the other side between the two lateral halves of the udder, and all around, it sends into the substance of the gland a number of thin divisions which map out the organ into lobules.

Abdominal. —Latin, abdomen, the belly; <»»««. a gating

Lobules.—Diminutive of the Greek lobos, a lobe. A subdivision of a gland,

The nutrient or arterial blood is supplied by the external pudic artery HI, which passes through a passage in the abdominal wall, termed the inguinal canal, and on reaching the outside, now beneath the hase of the mammary gland, it breaks up into two vessels, the superficial abdominal G, and the mammary artery 82.

The mammary artery plunges into the gland-substance, and soon forms six branches, of which the fifth for the greater part of its course follows the direction of the boundary between the fore and the hind quarters.

The veins of the mammary glands are divided into superficial and deep.

The superficial veins of the udder anastomose with each other, with those of the quarters of the opposite side, and have also communicating branches with the external pudic vein Al. 1 hese veins finally unite in front of the udder to form a very large vessel, the subcutaneous abdominal , or milk vein H.

The milk-vein from each half of the udder unites with its fellow of the opposite side iu front of that organ, and immediately afterward divides to form the two milk-veins which pass along the under surface of the abdomen, the wall of which they enter near the sternum.

They then join, or anastomose with, the internal thoracic veins. The deep mammary veins are satellites of the artery, and unite eventually to form the external pudic vein Al.

The veins of the udder are exceedingly numerous, and so also are the lymphatic or absorbent vessels. The large lymphatic yhind seen in section at D is situated just behind the external opening of the inguinal canal.

It receives a very large number ot afferent lymphatic vessels from the udder, with a few from the abdominal wall, and the inside of the thighs. rn i /v* t I I ! ' _ ._ 1 .... 1. 1. -.. .. 1 a .ft v. .v +l, n I.ii i d nvn ta nr

The efferent lymphatic vessels, or those leaving the gland, are tew in number, there being but five, or never more than six, and they

Inguinal.—Latin, inguen, the groin.

Mammary. Latin, mamma, the breast.

Anastomose.—To unite one vessel with another. Greek, aua } through; stoma , a mouth.

Subcutaneous. —Latin, sub, under; Cutis, the skin

Sternum. —Greek, sternon , the breast, the breast-bone. t r . • i i. . fillu f.Vin ahcnrKpnhe nr 1 vmn'hsi.hi i

Lymph.—Latin, lympha, water, the fluid which fills the absorbents or lymphatn vessels. * T - ft r

Afferent. —Latin, ajjero, I bring.

Efferent. —Latin, ef, out ; fero I carry.

enter the abdomen through the inguinal canal in company with the external pudic artery, its satellite vein, and the external inguinal nerve. The external inguinal nerve is derived from the third lumbar pair.

The gland tissue is made up of an enormous number of minute vesicles or acini, surrounded by a network of minute blood-vessels or capillaries.. These acini are clustered round and open into small tubes called the lactiferous ducts, the whole being held together by strong connective tissue.

The milk is formed in the acini and conveyed to a cavity at the base of the teat called the galactophorous sinus (L) or milk-cistern, from whence it is drawn through the orifice at the extremity of the teat (O).

The galactophorous sinuses arc very small in dry cows, but during lactation are much increased in size, and capable of great distension. They hold the milk which is slowly formed between milkings, or sucking by the calf, but the quantity they contain is not comparable to the amount withdrawn at a milking. A great deal more is contained within the acini and lactiferous ducts, in addition to which, bv reflex nervous action, a quantity of milk is actually formed during the process of milking.

Acini.—Latin, acinus, a berry. Applied to the enlarged terminals of the lactiferous ducts as indicating their resemblance to the cavity left in a berrv when the seeds have been removed.

Lactiferous.—Latin, lac , milk ; fero , I bear.

Galactophokous.—Greek, gala, milk ; phoreo, I carry.

Lactation.—-Latin, lactation, to bear milk.

The mammilla or teats have somewhat thick walls, M, and a single orifice seen at O.

The walls are composed of skin, and what is known as dartoid tissue, a mixture of elastic and unstriped muscular fibres. The muscle-fibres are both circular and longitudinal, and the teats are capable of a kind of erection.

At the,base of each teat the muscle-fibres are very few indeed but become more numerous as the free extremity is approached where they form a sphincter, which, by keeping the orifice closed, prevents the passive flow of milk.

A thickening exists at the base of the teat where the rupee arc large, and this was formerly regarded as a sphincter.

A sphincter to close an orifice, however, must consist of very well-developed muscular fibres, which have a circular direction. The number of muscle-fibres in the dartoid tissue near the base of the teat is very small, and, moreover, there would be no useful purpose served in having a true sphincter in this situation.

The large ruga; at the base of the teat probably hold up the milk, when there is very little in the galactophorous sinus, by simple passive contact; but when the sinuses are at ail distended, as every dairyman knows, the teats are very prominent, and they too are full of milk.

Mammilla.—Latin, mammilla, nipples or teats.

Dartoid. —Greek, dartos, a fleshy covering.

Sphincter.—Greek, sphingkter , that which contracts

Rug.e. -Latin, ruga, wrinkles.

\esicle.—Latin, vesicula , a little bladder. A bladdcr-like cavity.

Fig. 1.

Entered a. Stationer,’ H.„, SECT ' ON 0F ONE HALF ° F ™E UDDER OF THE COW. [Drawn by H. C. Wilkie.

SECTION OF ONE HALF OF THE UDDER OF THE COW.

Al. The external pudic vein.

A2. The mammary vein

HI. The external pudic artery

82, The mammary artery

C. The external inguinal nerve

D. Lymphatic gland (in section).

E. Skin,

F. That portion of the fibrous tunic of the udder which is in contact with the abdominal tunic.

( j . The superficial abdominal artery

11. The subcutaneous abdominal vein

I. Fat

J. The fibrous tunic of yellow elastic tissue

K. Orifices of lactiferous ducts, of which there are a very large number opening into the galactophorous sinuses.

L, The milk-cisterns, or galactophorous sinuses.

- * -) o ~r M. Walls of the teat.

N. Interior of the teat, showing its lining-membrane

O. Orifice oi' tlie teat

FIG. 2. DIAGRAMMATIC SECTION OF HIGHLY MAGNIFIED GLAND TISSUE.

This diagram shows the parts which may be recognised on examination of a very small portion of tissue from the mammary gland, under the microscope.

The full extent of one acinus A is seen in section. The immediate passage out of the acinus, the intralobular duct, is shown at E, which soon opens into the larger passage D ( interlobular duct). This latter after receiving in its course the milk from a large number of acini, finally finds its way into the galactophorovs sinus or milk cistern.

As is seen in the drawing, the acini are lined by cells, which have the special property of secreting from the blood (not directly, but through the medium of the lymph which bathes the tissues) the various constituents of milk.

The entire gland is richly supplied with blood conveyed by the minute ramifications of the vessels previously described, thin-walled capillaries which surround each acinus in a dense network. Lymphspaces also surround the acini, and these lead into networks of lymphatic vessels of the interlobular connective tissue. From this supply of nutrient material the cells lining the acini, by the special selective power with which they are endowed, manufacture milksugar and casein (which are not elsewhere found in the blood), and separate out water, albumin, and various salts. The fats of milk are, however, produced in a somewhat different manner. They are the result of a fatty metamorphosis of the cell-contents at the expense of which thev are formed.

It was formerly supposed that the casein was derived from the cell-contents or protoplasm, and that it existed as a coat around the fat globules. This coat was called Ascherson’s membrane.

Recent investigations, however, have proved that, there is no caseous membrane around the fat globules, and that the casein occurs in milk in tiny jelly-like masses in combination with calcium oxide. (McConnell, Burnthsten, Fleishmann, Snyder, and others.) mi . • . it. 7,. /... 1 .. ... L* i?- a. : j. l : _ l _

The size of the globules of fat is a matter of some importance. It has been estimated that the largest globules found in cream are 'OOO5 in. in diameter, the smallest about one-tenth of this. The size of the globules, however, varies in different breeds, being largest in the Jerseys, and there is a gradual tendency towards diminution in size from about a month after calving onwards. The

Intralobular. —Latin, inlra, within. Within the lobules.

Interlobular. —Latin, inter, between. Between the lobules.

Lymph.—Latin, lympha, water. The colourless fluid which fills the lymphatic, or absorbent vessels.

Capillaries.— Latin, capilla, a hair.

Casein. —Latin, caseus, cheese.

Protoplasm. — Greek, protos, first ; plasma, a formation (an elementary basis).

larger globules of course rise most, rapidly as cream, and arc most quickly churned, while milk containing small fat-globules is most suitable for cheese-making. Milk is an alkaline fluid, which readily becomes acid, and it has a specific gravity varying between 1,028 and 1,032, water being 1,000.

It is a typical food, because it contains all the necessary constituents for the nourishment and growth of the young animal. T ’ . .1 1 1 - _ a ~ f n4n ffo n Itwocatl f Dll 111 t lIP

In it the three great classes of food-stuffs are represented in the following way :

1. The proteids, or nitrogenous compounds, by casein and albumin.

2. The carbohydrates, by milk-sugar (lactin), and galactose (lactose).

3. The fats, by the fat-globules, which consist of olein, stearin, palmitin, butyrin, caproin, and six other fats of less importance, and in small quantities.

Ordinary whole cow’s milk should consist of thirteen, or not less than twelve, per cent, of solids.

An average composition is as follows ;

Parts.

Water ... ... ... ... , ... 870

Albuminoids (casein and albumin) ... ... 4 0 ry .1. _ i / :n_ A .a

Carbohydrates (milk-sugar) ... ... ... 4 6

Fat ... ... ... 37

Ash (salts) ... ... ... ... ... O'7

100 0

The first milk after calving differs from ordinary milk in many important particulars.

This is called the colostrum, and it acts upon the young animal as an aperient.

It is a viscid yellowish-white fluid with an unpleasant taste, and a greater density than ordinary milk.

It is very rich in solids, and contains numerous ovoid bodies from the acini, called colostrum corpuscles, which have a tendency to adhere in small masses.

The following analysis of colostrum will show how it differs from ordinary milk ;

Boussingault.

Water ... ... ... ... ... 75-8

Albuminoids ... ... ... ... ... 150

Fat ... ... ... ... ... ... 2-6

Milk-sugar ... .. ... ... ... 36

Ash .. ... ... ... ... ... 3-0

1000

The colostrum disappears on the third, fourth, or fifth day after calving, and the milk then becomes of the ordinary composition.

Colostrum.—Latin colostrum, tho first milk alter delivery

The albumin of ordinary milk does not usually exceed 0'54 per cent, of the whole.

The albumin of colostrum, and of milk towards the end of lactation, frequently reaches from 7 to 10 per cent, of the whole in amount.

Casein is one of the most interesting of the constituents of milk, as it is its chief proteid, and occurs in ordinary milk to the extent of about 3'04 per cent., or sometimes a little more.

It is very nearly allied to legutnin, which is found in all plants, but to a large amount in peas and beans. A form of cheese, indeed, is made from peas in China, especially around Canton.

Albumin—Latin albumen, white of egg ; from albns, white

Legumin.—Latin, legumen, pulse. The casein of plants,

Casein is coagulated by rennet (as in the process of cheesemaking), and also by the mineral acids, alcohol, and creosote.

It forms insoluble precipitates with such poisonous salts as acetate of lead, nitrate of silver, corrosive sublimate, &c., and hence the value of milk as an antidote in poisoning by these agents.

Casein is not coagulated by heat, and no precipitation occurs even at a temperature of 212° Fahr.

The salts contained in the ash of milk are numerous, and consist principally of phosphates, chloride, and citrate of potassium, chloride of sodium, phosphates of calcium and magnesium, with traces of fluoride of calcium, oxide of iron, and iodine. Oxide of calcium also is found in combination with casein.

Rennet. —Dutch, rcnnen, to curdle

DIAGRAMMATIC SECTION OF HIGHLY MAGNIFIED GLAND TISSUE. [Drawn by H. C. Wilkib. Entered at Stationers’ Hall, 1903, J

DIAGRAMMATIC SECTION OF HIGHLY MAGNIFIED GLAND TISSUE.

AA. Acini seen in cross-section,

88. Basement membrane supporting the epithelial or lining cells of the acini.

C. Interstitial connective tissue

D. Interlobular duct.

EE. Intralobular duct.

FF. Fat-globules (many of which can be seen still within the cells;

G. Duct cut across.

H. Blood-vessel.

Interstitial.— Latin interslitium, apace between— inter, between ; sisto , I stand.

FIG. 3. SECTION OF ONE HALF OF THE UDDER OF THE EWE.

This drawing shows a section through one lateral half of the udder of the ewe, exposing the main trunks of its blood-vessels, its lymphatic glands, its large galactophorous sinus, and the long pointed teat characteristic of ovine animals.

The udder of the ewe consists of two lateral halves, each of which is a distinct gland in itself, being separated from that of the other side by two layers of the fibrous tunic D and F, which are continuations of the tunic covering the whole of each gland or half of the udder. The broad suspensory bauds are similar to those of the cow.

The skin which covers the organ is white (or flesh-coloured), and a deep median furrow marks the limits of the two glands. fPL 1.....1. . I .. .. 1 ..unnii/inllil l/lnillinnl until I lift f AT flirt AA Ilf

The glandular tissue is practically identical with that of the cow, and the nutrient arterial blood is conveyed in a similar way by the external pudic artery, which is a fair-sized vessel.

The veins are of two kinds, superficial and deep. The subcutaneous abdominal vein is, like that of the cow, made up of a large number of anastomosing vessels, but it is not relatively so large as in that animal.

The deep veins are small, but numerous, and unite to form the external pudic vein.

The lymphatic glands (C) lie in a mass of fat behind the external inguinal ring.

They consist of two, or sometimes more, moderate-sized kidneyshaped glands to each lateral half of the udder, and they receive the

afferent lymphatic vessels from the glandular tissue, the efferents passing with the blood-vessels and nerve through the inguinal canal. . * . ■ io 1 o nnrl umnpwhflt

The galactophorous sinus in the ewe is large, and somewnai similar in construction to that of the cow, but the pillars around the openings of the lactiferous ducts arc more prominent, and these openings are relatively larger. ... i P i 1 , . . 1 .. .rr* »>en I'lUI/D O G 111

The lining-membrane of the teat shows no tranverse ruga, as in the cow, but its small folds take a longitudinal direction. r.x. •;/ 4.1.aut0 1.00 oDuorn 1 ftrifttio

The mammilla, or teat, of the ewe has several cnaracierisiic features. _ I • I • 1 1 11 I- 1 l-lm il/l/lfl» mwi

It is long, thin, and pointed, laterally placed on the udder, and projects considerably forwards as well as downwards.

Its walls are thin, and it has a distinct sphincter of circular muscular fibres around the single orifice of its free extremity, which is marked with a peculiar lip-like prominence (J).

The milk of the ewe is very rich in fat and albuminoids, and shows total solids to the extent of nineteen per cent. It is capable of making an excellent cheese, as is seen in the production ol rubiole, which is made in Italy from the milk of ewes.

The following is about an average analysis of the composition of normal ewe’s milk :

I)oy6re

Water ... ... ■■■ 8160

Casein ... ... ... ... 4UU

Albumin ... ... ... ... I‘7o

Fat ... ... ... ... ••• 7'50

Sugar ... ... ... ... ... 4-30

Ash 090

10000

SECTION OF ONE HALF OF THE UDDER OF THE FWF [Drawn by H. 0. Wilkie. L, Y Y Lr. Entered at Stationers’ Hall, 1903.]

SECTION OF ONE HALF OF THE UDDER OF THE EWE.

A. The mammary artery

B. The mammary vein

CC. Lymphatic glands

D. Fibrous tunic in contact with that of the abdominal wall

E. Skin

P. Fibrous covering or tunic

G. Galactophorous sinus

HH. Openings of lactiferous ducts

I. Lining-membrane of the teat.

J. External orifice of the teat

FIG. 4. SECTION OF ONE HALF OF THE UDDER OF THE MARE.

This drawing shows a section through one lateral half of the udder of the mare, with its teat, and exhibits the characteristic shape ol the gland, the larger trunks of the blood-vessels, the lymphatic glands, ga/actophorous sinuses, with the entrances of the lactiferous ducts, and the passages through the teat to the external orifices.

1 he udder of the mare consists of two lateral halves, separated by a narrow furrow, each half being provided with a single teat. the skin which covers the organ is black in colour, thin, smooth, and greasy, being supplied with numerous large sebaceous glands.

Lh e glandular tissue is of the same general construction as that of the cow’s udder, being composed of acini, with their secreting cells, surrounded by networks of capillary vessels and lymph-spaces, the whole supported by strong elastic connective tissue.

Ihe galactophorous sinuses in the mare differ very considerably Irom those of the cow, as there are always two, sometimes even three or four, opening into the teat, which has two or more external orifices.

The sinuses, however, are small in capacity, and exhibit a limited number of somewhat large openings, which are the general confluents of a considerable number of lactiferous ducts (H).

The mammary artery is from the external pudic as in the cow but the nerves are from the first lumbar pair.

The veins are very numerous, and are divided into superficial and deep.

Ihe subcutaneous abdominal or, as it is often here called, the posterior abdominal vein is of small capacity, and does not bear any comparison with that of the cow, while the deep veins are verv similar to those of the latter animal, as they are of considerable size, and unite to form the external pudic vein. mi i > .• i i . . . .....

The lymphatic glands, situated immediately behind the bloodvessels and nerves, as they pass through the external inguinal ring

Sebaceous.— Latin, sebum , any fatty matter. Sebaceous glands secrete an oily matter for the lubrication of the hairs and skin.

to the inguinal canal, consist of a cluster of numerous small round bodies as seen at C. Their afferent and efferent vessels are collectively very similar in number and origin to those described as passing to and from the glands in the cow’s udder. mi ... r 1... i- —«« , » 11 vw non nwn oh /\ ri 111 vi 4 n*i/i

The mammilla;, or teats, two in number, are short, blunt, and flattened from side to side ; they are covered with very smooth, thin, black skin, and usually have three or four orifices each at the free extremity.

In many cases, however, only two of these are perforate, and this is the most usual number from which to obtain milk in the mare.

Around the walls of the teat are found numerous bundles of both circular and longitudinal muscular fibres, the circular fibres forming sphincters around the orifices.

The lining-membrane of the passages in the teat does not show any rugae, or transverse wrinkles as in the cow, but its few folds are disposed in a longitudinal direction. The milk of the mare, as in most of the herbivora, is alkaline, and it is the most easily digested of all milks, which fact has an important bearing on the artificial rearing of foals.

A foster-mother for a foal is not always easily obtained, as so many mares refuse to allow a strange foal to suck. In rearing a foal by hand, where only cow’s milk is available, it is necessary that this should be made to approach as nearly as possible the composition of normal mare’s milk, which may be stated as the following :

Snyder,

Water ... ... ... ... ... 88-49

Casein ... ... ... ... ... 3-00

Albumin ... ... ... ... q-35

Sugar ... ... ... ... ... 4.75

* at ... ... ... 2-86

• • • • ••• ••• ... OU Ash ... ... ... ... ... 055

10000

Colostrum, a necessity for the calf, is even a greater one for the foal, whose bowels are still more apt to require a gentle purgative at birth.

SECTION OF ONE HALF OF THE UDDER OF THE MARE. [Drawn by H. C. Wilkie. Entered at Stationers’ Hall. 190: i

SECTION OF ONE HALF OF THE UDDER OF THE MARE.

A. The mammary artery

B. The mammary vein.

C. Lymphatic glands.

D. Fibrous tunic of the mammary glands which is in contact with that of the abdomen.

E. The external aspect of the other lateral half of the mammary gland.

F. Skin,

G. Fibrous tunic.

H. Openings of lactiferous ducts.

I. The galactophorons sinus.

,TJ. The internal passages in the teat, showing the longitudinal folds of its lining-membrane.

K. Two orifices at the free extremity of the teat

By Authority: John Mackay, Government Printer, Wellington.—l9o4.

[l,OOO/ 10/190H—8301