SHEEP-DIPPING.

Otago Witness, Issue 3383, 15 January 1919, Page 8

SHEEP-DIPPING.

At present the Stock Act allows sheepfarmers in New 'Zealand to dip their sheep during the months of January, February, March, and April—in the North Island during the first three months, and in the South Island during the latter three months. The inspector has" power to extend the period in the event of a dry season and shortage of water to anyone applying for an extension of time. It is quite conceivable, if sheep-owners were not so apathetic, that, both ticks and lice could be eliminated entirely from this Dominion, although doubtless the Stock Act would require some amending. We have to deal with the pest as we have it, however. It is essential to use a dipping mixture, which is guaranteed effective, and to adhere closely to the directions in regard to mixing, etc. It is no advantage to experiment with a _ view to economy with a cheap sheep-dip concoction. The rams should, be dipped a considerable time before they are to be used, and some weeks should elapse after the ewes have been dipped ere the rams are turned out. No hard-and-fast rules can be laid down in regard to dipping off the shears, and again later on, as there are losses enough in all conscience this season wherever we look; but we should never forget that the result of but one dipping merely kills the adult ticks, while a second dipping after a period would kill the ticks that emerge later on. It may be as well to refresh our minds in regard to the life history of the sheep tick. It is peculiar to aheep, and it is . generally recognised that five days may be regarded as the maximum time a sheep tick can live apart from its natural host, and the pupal state lasts about three weeks. Nearly all insects have four stages—egg, larva, pupa, and the perfect insect. , The pupa_ is commonly regarded as the egg. but .it is not an egg in any sense. In the case of the sheep tick, the stage and the larval stage are spent within the body of the mother, and it is only when the Jarval stage is complete that the larva is born in the natural sense. will not destroy the pupa case, which is a hard, impermeable covering, expressly designed by Nature to protect it from adverse exterior circumstances. Practically speaking, no ordinary or extraordinary amount of* soaking in dip will deter the developed tick, from emerging' in due course. What if the sheep tick is comparatively a slow breeder? If the four or five pupee survive the dipping, they will, if left alone, readily multiply and perpetuate the pest ad arbitrium. The period of pupation is, on an average, say three weeks, so if infested sheep are dipped twice at intervals of 24 days apart all the ticks on sheep would be destroyed. We have said nothing as to the harm, done to the wool and possible death of the sheep if recourse is made to doubling the _ strength of the dipping mixture with an idea that the result will be clean sheep. This is no bogey. We know of deaths occurring as a result of this ridiculous practice of using: double strength. The dipping, if done with due regard to common-sense precautions, means a higher price per lb of wool than if wool is both tick-stained and dirty. The clean sheep will enjoy bodily comfort, while the stimulating effects on the skin provides the best conditions for growing sound and healthy fibres and typical wool of its class. With ordinarv care the ewes and lambs iray be dipped together. There may be some slight risk in the case of the lambs, when a poisonous dip is used, but not sufficient to iustify scamping the operation. The risk arises from joining up the ewes and lambs too soon : but there are the non-poisonous dips, which on occasions may well be adopted in the case of lambs with practically no risk whatsoever. No one with any experience would wish 'to try and fatten "ticky" lambs a second time. They snend the greater part of their time rubbing and scratching against the fences, destroying enough expensive feed to turn clean lambs off "fat," ready for the works, iust because they are tormented by pests which might well have been killed. The fattening qualities of dipped lambs and sheep intended to be fattened are quickened, and there is a greater and faster increase of the carcase. Dipping should be finished early in the day, and sheep should not be heated by being driven fast to the yards. In fact, they" should, if possible, be Tested at the yards before commencing operations, with Increased chances of keeping the dipping mixture fairly clean. There is little doubt that sheep infested with irritating vermin cannot thrive ai they ought to, while the

cost of feeding the vermin is no trifling matter. Dipping will not grow wool on bare places, but it helps, by promoting a healthy skin and consequently a healthy growth of wool of a character impossible of obtaining under conditions pertaining to sheep undipped.