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The Pamphlet Collection of Sir Robert Stout: Volume 72

Some Diseases in Sheep and Some Preventives

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Some Diseases in Sheep and Some Preventives.


In dealing with the question of diseases among sheep, I propose to treat the subject on the lines of prevention and not of cure. Absolute prevention is an impossibility, for there are certain insidious diseases which break out periodically in the best managed flocks which no care on the part of the owner can avert, and New Zealand is not exempt from such cases, but fortunately they are not common or widespread in their effects. One of such cases is the complaint which attacks pregnant ewes, usually two or three weeks before lambing time, and is sometimes very fatal. With us in Canterbury the complaint has occurred to my own knowledge at varying intervals and in varying localities many times during the last 20 years. One peculiarity of the disease, as far as my own observation goes, and as far as I have been able to learn from other persons, is that the fatal cases are almost invariably among ewes carrying twins. So markedly is this a feature attending the disease that there seems to be a close connection between twin gestation, and at any rate fatal consequences. But doubtless many animals are attacked without fatal consequences ensuing. My reason for this belief is that among the survivors of a flock where deaths from the disease have taken place, are many ewes that rapidly fall off in condition after lambing, with a rapid diminution, and then cessation of milk supply, to the great injury of the lambs. The lambs of such ewes quickly assume the appearance of being motherless. As far as I know no remedy has been found for the malady, and no preventive. It occurs at a time when curative treatment is most difficult to apply, on account of the advanced stage of pregnancy. It occurs in ewes of all ages and of all conditions. Fat ewes and lean ewes are alike subject to it. I have drawn attention to this complaint, because as yet it does not appear that any satisfactory preventive or cure has been found for it. No system of feeding or treatment within the compass of practical sheep farming, as it must be conducted in New Zealand, with due regard to our opportunities, and to the market value of sheep products has, I think, yet been discovered, and should it be discovered it will unquestionably be in the way of prevention.

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In this section of the subject I propose dealing with the mortality in lambs; but before touching on the main question, I should like to say a few words as to the condition it is desirable that ewes should be in at the time the rams are put in with them, and up to the time of lambing. I merely give my own opinion based on my own experience. My choice is that ewes should be in decidedly forward condition during both the above-mentioned periods. If they are not in condition when the rams go with them, the probability is they will not gain it through the following winter. As far as merino ewes are concerned, the experience of the early days of the colony shows that the most prolific lambings were at a time when the country was so lightly stocked that every sheep of every sex, on good sheep country, was fat. So much for merinos. As to half-breds, I believe the same rule applies. The heaviest lambings from half-bred ewes I have ever known was from sheep so fat at the time the sexes were joined that many persons would have pronounced them too fat for mutton. When the half-bred stage is passed, the ewes may become too gross for fertility-Excessive condition in any breed or degree of breed is certainly not necessary, but I think ewes should be in rather high condition than in any way low. Feed is not abundant or usually nutritious in the early lambing season, and the ewes should have some condition on them to stand the drain of suckling lambs at a time when the grass supply is insufficient to maintain both the condition of the mother and the necessary nourishment for the offspring.

Mortality among lambs happens not infrequently after cutting and tailing, and blood poisoning is the cause. The best preventive is undoubtedly not to use old yards for the operation, especially yards where any animals have been slaughtered, or where there is any accumulation of filth. The presence of either of these things is enough to engender life organisms which may taint the blood of any animal with an exposed wound. Farmers often use yards about a homestead which horses, cattle, pigs, &c, have been in the habit of occupying, and which have more or less of decaying matter about them. Such yards should not be used for any castrating operations. The better plan is to pitch a yard in some clean spot in an open field. This can be done easily with a few hurdles, or for large numbers of sheep with a few lengths of wire netting and hurdles for close work. This method will be found inexpensive, and very conducive to the well-being of the lambs. Mr. John Gilruth, V.S. is of the opinion that page 28 blood poisoning arises chiefly from micro-organisms which infest low-lying swampy localities. There is nothing improbable in the supposition that such spots do produce the result, for the germs of malarial diseases are well known to exist in marshy and swampy places, but I believe myself that the most frequent cause of blood poisoning is from old and dirty yards, and my own experience is that when those yards are abandoned and new ground chosen, the mortality in lambs from operations is infinitesimal.


Following the order of diseases in the sequence of age is that known as lungworm, and this disease developes itself in lambs or hoggets sometimes shortly after weaning, and sometimes at a greater interval, according to the climatic conditions of the autumn or winter. In a dry season there is a total or almost total absence from it, but in a wet time it is especially virulent. On damp land the disease is most active, though on dry sound land in certain seasons it is very destructive. As is the case generally with diseases, it most readily attacks lambs of delicate constitution, and in low condition. The healthier and better conditioned lambs are those that are least liable to it, and the more frequently survive an attack. The consideration then is how to build up and fortify our lambs against the disease—that is to say, make them as little susceptible to it as possible. In the first place something may be done by the selection of rams which display indications of great strength of constitution. But though this is a point of no small importance, it is secondary to that of establishing the constitution and condition of the young animal by a liberal supply of food from its birth. The constitution of any animal may be strengthened or weakened, according to the sufficiency or insufficiency of nourishment. It is a matter of great regret, and I may say of shame, and also of false economy, that so many sheep breeders persist in overstocking their pastures. Such sheep farming really comes under the heading of cruelty to animals, and is nowhere so prevalent as among the inexperienced sheepowners of the colonies—men whose pursuits were in other lines, or not in the practical management of stock before embarking in their new occupation. Many of these sheepowners look on numbers of sheep as the one desideratum, regardless of all other considerations. With such men, the circumstance of a blade of grass being as they think, wasted, is pain and anguish. But the fact is, no page 29 stock can be kept in proper condition if compelled to eat out every growth of coarse and unpalatable food. It is in this matter of feeding that the secret of condition in sheep, and greatly so of constitution, depends. "Who has not seen flocks which were originally almost all that could be desired, degenerate after a few years of semi-starvation into absolute culls? A general deterioration has taken place, and even the characteristics of the breed have become lost. Conversely, if such degenerated sheep pass into the hands of a skilful breeder, in a few generations the characteristics are restored. It is in attention to careful feeding that immunity from disease must chiefly be looked for. Build up the constitution and vigour of the sheep by an ample supply of natural food. I do not mean pampering with high artificial feeding,—that course in itself brings a certain form of delicacy of constitution—but of natural and wholesome food there should be no stint. If any breeder desires strong and healthy lambs, he will not get them in any other way. But what I have always considered as a great help to strength and vigour is, that lambs should be dropped as early as the climatic conditions of a farm will permit. The earlier lambs are dropped the more robust are they, and the more capable of enduring the hardships of the first-winter, and it is advisable, I think, that on front country the lambings should be as early as possible. An early dropped lamb has this advantage over a late dropped one that it has the benefit of the first flush of spring grass, which increases the milk supply of the ewe, and maintains it till the dry weather of summer sets in. By that time the lambs are pretty well independent of the mother, and are able to shift for themselves, even though the grass may be somewhat withered up. They suffer something however in these circumstances; and, if it can be arranged, the lambs should be weaned on to clover or rape, on which food their condition will be sustained, and it may be improved. Clover or rape are healthier foods than grass for weaning on, and if possible the lambs should be kept on such food till late in the autumn, and then put on to turnips of some soft kind, when the roots are ripe enough, but before they have lost their sappiness. If the feeding of turnips is postponed till most of the sap is gone lambs do not take so kindly to them, nor do they make so quick a start in improvement. Turnips are excellent feeding for hoggets, and it is doubtful if the crop can be used more profitably. If neither clover, rape, nor turnips are available, the lambs must take their chance; but if they have thriven well during the suckling period, and ordinary care is taken to keep them on the page 30 best grass the farm affords, there should be no great mortality from lungworm. Clover and rape are sounder feeding than grass, particularly if the latter is an old pasture. Corn and chaff as auxiliaries to grass during the winter are very beneficial to the health of sheep, but I do not look upon them as within the scope of practical sheep farming in anything like a large way.

The question of lambing a month or two earlier or later may seem a small matter, but in reality it makes an immense difference to the lambs powers of vitality if it has a month or two advance of age. Lungworm is a disease that is almost confined to lambs or hoggets. I understand that older sheep are sometimes affected with it, though I have never seen an instance; whether older sheep are liable to it or not there is no doubt that hoggets are the most liable, and if a month or two of age can be given by an early lambing the liability to disease is diminished, and the lambs go through the winter with greater freedom from any ailment or weakness. It is the same with other animals. Take the case of an early calf and a late one, both equally well reared, and note the difference in the two during the first winter. The older calf has a great advantage over the younger, much more than the mere fact of a slight advantage of age should apparently give. He has had the advantage of a full summer's grass before the winter begins. This is what gives him the hardiness to stand the winter well. So it is with lambs. It is as important to the lamb that it should have a full summer's grass as it is to the calf. These two qualities of good condition and early spring birth are the best resistants to disease, and it is possible to improve the condition of the lamb yet further, by shearing it at a suitable time, say in January. Lambs, like sheep, improve fast after the burden of the fleece is removed from them.

I cannot impress upon sheepowners too much the wisdom of treating their young stock liberally in the way of food. I do not say it is an absolute preventive of the disease we are speaking of, but it is a great safeguard, and quite apart from a reduced liability to sickness—it is wisdom on the score of general profit. An early lamb well fed becomes a marketable sheep at the age of 15 or 18 months, and sooner still if needed. It is large enough for every export or local purpose, and it is certainly something that a sheep should be sufficiently matured for slaughter at so early an age.


There is one more common disease, and that is footrot. It is fortunately not fatal, but it is very troublesome to cure, and is most page 31 contagious. It may be prevented, though, to a large extent by watchfulness and preventive measures. It breaks out spontaneously in wet seasons even on what is usually sound land. A continuance of wet weather causes an excessive growth of grass, which keeps the feet of the sheep constantly damp and develops the disease. A farmer who is alert will observe the signs which will lead to its development, and should take precautions against an outbreak. During a wet time of any extension it is prudent to pass the sheep occasionally through the footrot trough, containing a solution of arsenic, bluestone or carbolic, and as a preventive the solution need not be very strong. In this way, if care is taken, an outbreak and much future trouble and loss may be avoided. The disease is too serious to be trifled with on account of its extreme contagion and difficulty to cure, and on account of the very debilitating and attenuating nature of the disease. While on the subject of this disease, I will shortly depart from the rule I set myself at the outset—not to touch on the curative treatment of diseases. I have an idea which I should like to see carried out for curing footrot. The circumstances of my own farm do not make it necessary that I should make the experiment; the idea is this, that a flat concrete trough should be employed, and that the liquid should be kept at a suitable temperature by means of steam pipes surrounding or traversing the interior of the trough; a warm liquid is much more penetrating than a cold, and I know from small experiments I have made that it is much more effective as a cure. I believe if foot-rotty sheep were set to stand ten minutes or so in such a trough of warmed footrot solution of moderate strength, a cure would be rapidly effected, and that without the paring of the feet. In treating this disease the infected sheep should, if it can be managed, be separated from the sound, and the sheep when once dressed removed, if practicable, to ground which has not pastured infected sheep. Unhappily few farms afford this convenience.

This paper only deals with a few of the more common of sheep diseases, and if I have laid much stress on the preventive aspect of the question, it is not because I think slightingly of curative treatment, only that prevention is, I think, the more important.