FARM AND STATION

Hawke's Bay Tribune, Volume XIX, Issue 67, 6 March 1929, Page 9

FARM AND STATION

Causes of Disease in Sheep

Over Condition, Lack of Exercise, and Unsuitable Environment

Steps Towards Rectifying the Condition

When we taken into consideration the fact that domesticated sheep are, in the majority of cases, bred and kept under conditions absolutely dissimilar to those for which Nature designed these animals, it is surprising that they are not subject to more diseases than those which at present ravage our flocks.

As far as we can learn from the rather meagre early history of sheep, the present domesticated animals were derived from native breeds which inhabited the mountainous parts of Africa, Arabia, Persia and Southern Russia. Being mountain animals they throve best on short; nourishing pasture, and while they could survive with little in the way of drinking water, they were used to dry feeding and camping grounds, and apparently were most suitable to comparatively hot climates. In Biblical times, and even until within a couple of centuries ago, sheep were not confined within fences, but were herded on open uplands, being driven for safety to folds at night, but having wide range with abundant exercise every day. Under these conditions there was very little sickness or disease, the usual causes of losses being wild animals or severe storms. With the closer settlement of lands and the defining of boundaries between various owners, fencing into smaller and smaller areas has become the rule, and the stock, no longer requiring folding at night or shepherding throughout the day, has been left undisturbed to feed and fatten on the improved pastures provided.

SHEEP USUALLY UNHEALTHILY FAT.

As under modern sheepfarming conditions there has been less and less necessity for the animals to bestir themselves in search of food, they have become unhealthily fat throughout the whole year, and less and less inclined to take the exercise necessary to keep both their muscles and their internal organs in a firm healthy state. This is of little consequence ’n sheep designed for mutton at an early age, but with breeding ewes it is the source of most of the troubles from which we suffer losses. When we learn that exercise and only sufficient condition to ensure perfect nourishment is the ideal condition for our breeding ewes, and devise means whereby' these can be efficiently controlled on the modern small farm, we will find that most of the diseases to which our flocks are at present subject will disappear.

SHEEP-SICK PASTURES.. As a direct result of grazing continuously with one class of stock over a confined area, we have sheep-sick pastures. In spite of apparent abundance of feed on sheep-sick land, the animals fail to thrive and become emaciated and profitless. This is largely the result of the land becoming fouled with disease germs and the eggs of internal parasites, which are passed on through the contaminated feed which the animals are forced to eat, from one sheep to another, until all are affected. There are other reasons for what we call “sheep-sickness” of pasture, such as the distaste which any animal has for grass which is fertilised by the droppings of its own species, and the fact that sheep, which are selective grazers, in time eat out and kill those ( varieties of grass which they find most palatable and nourishing, but when analysed, all these troubles will be found to be the direct result of confining sheep to small areas without adopting a system of management which would give them conditions approaching those to which their ancestors were fitted.

MINERAL DEFICIENCY. On small grazing farms also, there may be such a heavy drain on lime, phosphorus, salt, potash, iron and iodine, through the export of farm produce such as wool, mutton, etc., that the surface soil on which the grass grows becomes deficient in one or more of these essential minerals. On the open grazing lands of the past, deeprooting plants and herbs were continually bringing these minerals from the subsoil to the surface, and so replenishing the supply in the surface soZ.; now,, with the exception perhaps of lucerne, and one or two of the deep-rooting clovers, we do not allow any of these plants an I shrubs room in our paddocks.

Many of our stock ills may he directly’ traced to mineral deficiency, and in our management

of grazing country we must be continually on the alert to detect such shortage and supply it by one or other of the methods which scientific investigation has proved to be satisfactory.

ENVIRONMENT.

It was mentioned earlier in this article that sheep were naturally adapted to high, mountainous country. It can be appreciated then that when we ask the modern descendants of these sheep to live on damp lowlands and in cold, wet climates, we are expecting them to thrive under exactly opposite conditions from those to which they are adapted.

Fluke and footrot follow as a natural consequence, while the sheep fail to thrive on the rank but comparatively innutritions grasses which are available. The sheep has not a very big capacity for food, and hence, to provide for growth and profit, must have highly nourishing food. On rank pasture, in spite of apparent abundance on all sides, a sheep simply cannot eat sufficient to supply itself, and possibly its lamb, with the nourishment required.

DIAGNOSING THE TROUBLE.

When we find disease, or perhaps merely unthriftiness in our breeding flock it should be possible, with a knowledge of the past history’ of, the sheep, to trace the trouble back to its source, and by rectifying to reduce, if not entirely eliminate, the trouble. In their order of importance we will usually find that disease results from over-condition and lack of exercise ; internal parasites and fouled pastures; mineral deficiency ; or envioronment unsuitable for grazing sheep. As, by better management in grazing the paddocks rotationally, always keeping the sheep moving on to clean, short pasture; and by supplying mineral deficiency’ through the medium of top-dressing; by licks, or by both, we approach more natural conditions, we will find disease become more and more rare amongst our flocks.