DISEASES IN, SHEEP.

Otago Witness, Issue 1762, 29 August 1885, Page 6

DISEASES IN, SHEEP.

ANiEMIA. Professor Robertson, Principal of the Roya Veterinary College, has recently contributed ah article to the Journalof the Royal Agricultura Society on a disease very .prevalent among sheep in all parts of the' world." The affection treated of in the article in question is known by the name of " anaemia," also more familiarly by the terms "wasting," " hunger rot," or "blood rot.' Large numbers of sheep are lost every year in Great Britain from this cause, but. the disease is not ' confined to any' district, or particular breed, or age of sheep, as it makes its presence known also in America and Australasia. It is important that sheepfarmers should , be ao quainted with the cause of any serious mortality in their flocks, and also the means of preventing the continuance of the same. Though all breeds and classes of sheep may be affected, yet there seems to be no doubt that some are greater sufferers than others, and in certain districts or localities it is more constantly observed than in others. Of the different classes, young sheep, " hoggets," both fattening and store animals, and breeding ewes, furnish the greater number of victims. The frequency of its appearance in these classes can, says Professor Robertson, be readily explained by reference chiefly to the'influence cf dietetic causes. But in the first place it will be necessary to give some definition of the terms applied to this disease. Aruemia is employed to indicate that diseased state in which there is deficiency in amount of the circulating blood, local or general; it also includes deficiency of certain of the essential constituent elements of the blood, particularly of the formed elements, the globules, and of the albuminous. Various and somewhat different causes are found to operate in the production of anaemia as a diseased condition, the chief of these being a deficient supply of blood or of bloodyforming materials, exces.sive waste of these, or a combination of both classes of factors. The terms "hunger rot" and ''blood rot" are applied to this disease owing to the similarity of the symptoms tp thosp of the liver-disease known as " rot." In the greater number of cases of anaemia there exists a want of rej&tfre balance between thje requirements of the system and the nutriment J supplied. The food supply may be in a certain sense abundant, but on examination it will ulti* mately be found inadequately provided with materials fitted for the manufacture of healthy blood. In no case, says Professor Robertson, have I encountered anaemia where the BfJfrhas been of a mixed character ; and in every extent sive outbreak the food material, whatever ifc was or in whatever quantity allowed, has been characterised by one feature — sameness ; white those animals in which exhaustion had not pro* ceeded too far were invariably restored to health by means of a change of diet or an addition to the existing one of some other material. Although anaemia is of less frequent occurrence during the summer, it does not appear that the seasons have so much to do with ite appearance as the varieties of 60il. This no doubt is accounted for by the fact that meteorological -^nditions do not influence the character of the ~'~* of animals nearly so much as the «~~ ' J ~ n Of , a. soil, and its manurft 1 plant loov. "^uih piants so geological format jv,^ -*■ When poverty or richness uponwi^ L largely depend for their support anremia appears during the summer amongst sheep on pastures it will generally be found first on such lands as are of "a weak, mo'ory character, which have been considerably altered by cultiva- ■ tion, and where the sheep have been retained ■/* upon this kind of soil for exceptionally \onfott periods without change, conditions which are exceedingly liable to produce a variety of serious diseases amongst sheep. Water-meadows are very apt to produce it, and also pastures of rank immature grass produced by moist seasons. But this disease is very much more frequent in Britain during the' winter and spring, more ! particularly amongst sheep that have been fed exclusively upoa turnips grown on weak moory

land, by which it is presumed the Professor means land of a sour washy nature, and full of moss and innutritious grass in its native state. Anajmia also makes its appearance in flocks that nave been pastured during the summer on very rank meadow grass and are put on root crops in winter without hay, corn, or cake. Turnips are no doubt ail excellent food when used iv conjunction with other and drier food, but they are,' says the Professor, comparatively worthless alone to maintain sheep in a healthy and vigoroW condition. And in seasons when roots are abundant farmers are apt to confine both young sheep and breeding ewes on the roots alone, by which means Professor Robertson thinks the roots are worse than thrown away. The liberal and unrestricted use of turnips' is always more or less 'disappointing in its results unless supplemented by food of a totally different nature. Next to the exclusive use of turnips as a means of inducing a poor and weak condition of the blood, luxuriant grass of autumn growth, from its low nutritive value, is found to operate detrimentally upon breeding ewes if confined upon it during the critical period of gestation. It seems from" the foregoing that any food materials, containing aii T excess of moisture, and therefore deficient in flesh-forming constituents, are apt to cause a falling off in the Strength and quantity of thejblood. It is in the blood that after-death appearances point to ameinia as feeing the cause of ; death. The large veins when cut. yield a very small quantity of blood, and any ordinary .observer notices the. pale, bloodless condition of the body.- The specific gravity of the blood is lessened, and' it loses its power of coagulating to a great extent, if not altogether. With regard to the symptoms of this affection, the writer says that the earnest indications are apt to be overlooked or disregarded, -unless previous experience causes ,tbe observer to be on lihe look-out. . The suspicion that the sheep are not thriving or laying on flesh as they ought to do., soon Jjecomes a certainty that something is seriously wrong with them. , At first the death rate is not alarming, but in a few weeks, with unaltered conditions, the mortality will increase to' an alarming extent. Careful examination of the flock will 'show that a large number are unnaturally dry-looking in their wool and tucked up in their bellies ; the food consumed is not as much as it should be, and the skin will not move freely, but feels hard; and the impression formed is that the" sheep are losing instead of gaining flesh.', t A listlessness and want of energy will be Observed and ah evident unfituess for any exer-, tion. In' severe and prolonged cases there is general depravity of appetite, with inability to digest or assimilate the most digestible and nutritious food, and a state of coma or stupor ushers in thfe last stage.

. The treatment prescribed may be stated in a few words — namely, change of food or a.i addition of food of a different nature to ihat winch causes the mischief. Removing the sheep to land of a different nature — as was stated in the outset, soil has a great deal to, do with the health' of the flock, as it affects the quality of the food produced, by it, — and the addition of a little artificial food, such as oats and bran or a little linseed cake, will 'generally serve the purpose, 'well. Where 'prevention is the obiect rather than thecure the same rule applies. With breeding ewes it is said that it is very important to ; consider their dietary during the winter months in relation to the health of both mother and off spring. • ! ' J '•• The Professor gays that neither the grass of full and. fresh pastures nor an unlimited supply of roots' alone are sufficient food for pregnant animal's. In the ewe anseinia may be the result of 'such feeding,' and in the lamb the bad effects of defective nutrition will always be apparent. The safest plan with breeding ewes is to keep them during the 'middle and later periods of pregnancy upon rather' bare pasture, and give them a sufficient amount of chopped hay or straw with corn and bran to supplement the grass.