DIPPING SHEEP

New Zealand Herald, Volume LXXIII, Issue 22318, 16 January 1936, Page 16

DIPPING SHEEP

TASK SHOULD BE WELL DONE

OPERATIONS DESCRIBED

BY H.B.T

The attitude of a great many sheepfarmers toward dipping their ilock is quite a wrong one. They look upon anything that will comply with the dipping act as sufficient, and shun a job which requires to ho done well if it is nob to do the slice]) and wool more harm than good. Fine-woolled sheep, where the fleece is dense as with Merino, Southdown, halfbred and Ryeland breeds, are much less

subject to skin parasites than are the open-flecced long wools, presumably because the lice and ticks cannot reach tlie skin surface and move about readily in the fleece. When the ewe flock is affected with ticks or lice at shearing time, it is advisable also to shear the lambs, otherwise the parasites, deprived of the shelter on the ewes, transfer to the woolly lambs, with disastrous results to the latter. The only effective precaution is to dip the woolly lambs a week after their mothers have been shorn, using a fluid, "non-poisonous" dip. This, however, frequently gives the lambs a check, and may cause mismothering at a critical period. If the lambs can be shorn this will be found to be the best practice.

Dipping Shorn Sheep | Shorn sheep become reinfected from ' ticks, keds and lice eggs, which survive \on the sheep camps. To cope with | these the whole flock should be dipped j when a month off shears. There is then a sufficient growth of wool to re- : tain the dip in contact with the skin, j This will generally be found to be the ! most effective time to dip, using an ! arsenical sulphur dip, which is not very readily soluble in cold water, and hence does not easily wash out of the short fleece. As this type of powder or paste dip acts by poisoning the insects when they ! bite the skin of their host, it will be ! obvious that the dip constituents must i be precipitated directly on the skin and not only through the fleece. For this reason, again, dipping when the wool is comparatively short, as it is a month off shears, adds to the effectiveness of arsenical dips. It pays also to dip later in the season—in March or April—when the fleece is longer, if there is any sign of either ticks or lice, for these will increase rapidly as the sheep loses condition during the winter and may do ; untold harm to both sheep and wool, i For the later dipping a carbolic or J creosote dip, which kills by coming in | contact with the parasites, is generally j most effective, and is all that is necessary if the flock has been previously

dipped with an arsenical mixture a month off shears. Where only one dipping, in March, is the practice, an arsenical dip should be used and the sheep given plenty of time in the dip for the materials to reach the skin. This single dipping is, however, not recommended as it is seldom effective. Stirring the Bath The dip or bath should be thoroughly cleaned out and refilled with a mixture of known strength before the sheep are put through. Powder dips should be mixed in sufficient water to dissolve the materials for at least 12 hours before they are added to the bath, but fluid dips may be added immediately after mixing. As dipping progresses the bath should be kept thoroughly stirred with a plunger made from a pole with a flat board attached at right angles. If this is not done the heavier and undissolved constituents of the powder will sink to the bottom with resultant poor effect. It must be remembered, also, that as the sheep leave the bath they take away in their wool more dipping materials than they do moisture, most of the latter being drained back from the concrete •draining yards. This means that the fluid in the bath rapidly becomes weakened, and when filling with water to maintain the level of the dip, dissolved arsenical powder or fluid dip should be added in slightly stronger proportion to maintain the original solution strength. Where only hard water is available it is necessary to add sufficient washing soda, previously dissolved in hot water, to make the dip water lather freely with soap. Sulphur and arsenic—the chief ingredients in powder dips—will precipitate in hard water, but the soda will keep the arsenic soluble and encourage its penetration through the fleece to the Httin. Completing Mustering If sheep arc to be mustered and dipped on the same day, the mustering should bo completed as early as possible, and the sheep allowed to stand for a couple of hours to cool before they are put through, otherwise pneumonia may result. Pneumonia is also frequently caused by driving the sheep far or fast back to the paddocks after dipping. If possible, allow the sheep to dry out thoroughly in a big yard, or small paddock on a hill top, if such is available. Fat sheep and rams are most likely to suffer ill-effects from dipping, hence particular care should be taken with them. With valuable rams, it is generally safer not to put them through the swim dip. If they are held in a crush pen one man can hold the fleece open along the back and another pour about half a gallon of dipping mixture along the back from head to tail. This soon works round every part of the body next the skin and effectively kills ail parasites.

It is inadvisable to clip breeding ewes or rains within a fortnight of their being mated, or during the season when the rains are running with the ewes. The excitement and immersion appear to retard the ewes coming on season, and newly-dipped rams will take little interest in their duties. Losses From Pneumonia

Most of the losses following dipping result from pneumonia, to which the sheep is particularly susceptible. The chicl cause is inhalation of dipping solution. Generally the crutch is used far too much. Other causes of pneumonia are dipping too late in the day—not allowing the sheep time to dry out before nightfall—and driving too fast or too far while the sheep are wet. If these mistakes are avoided there should be 110 losses and, relieved of the parasites which continuously irritate them and sap their vitality, the sheep will thrive remarkably.

It is a fact that sheep carrying a fair amount of condition are not nearly so susceptible to tick and lice infestation as are poor-conditioned stock. Whether this is because the parasites cannot live on fat sheep, or because only parasite-free sheep get fat, is a problem which has never been satisfactorily answered. However, it is unquestionable that, parasite-free stock make most economic use of foodstuffs, and as dipping is the most effective known method of freeing them from ticks and lice, it is undoubtedly good and profitable business to dip them thoroughly, and as often as may be necessary.