Vaccination Against Contagious Abortion

New Zealand Journal of Agriculture, Volume 65, Issue 5, 16 November 1942, Page 277

Vaccination Against Contagious Abortion

THE attention of dairy-farmers who are having trouble with contagious abortion is again directed to the free vaccination of calves being made available by the Department of Agriculture. This was described in the September issue of the Journal. In order to enable the largest possible number to participate, the closing date for application has been extended to the 30th November. Applications on the form printed below should be forwarded to the Director, Animal Research Division, Department of Agriculture, Wellington.

the opening in the top of the pyramid into the trap above, from which they ” are unable to find their way out again. Dead flies are removed periodically and the bait renewed every 7-10 days. , Poison Bait ' Poison bait can be made by taking half a 40-gallon drum into which . is placed half a sheep carcase which has been left for 2-3 days to become thoroughly putrid. It is then half covered with 1 per cent, arsenic solution. The carcase is moistened from time to time by bailing the fluid over the exposed portion. The bait will attract and destroy flies for at least two months when it should be replaced- The drum should be fenced off to avoid risk of poisoning other animals and should be placed in a sheltered position such as the lee side of a tree. Carcase Disposal Carcases of stock- and game afford an excellent breeding place for large numbers of blowflies and should be destroyed as soon as possible after death. r Burning is the best method of disposal and where firewood is scarce spraying with one-third to one-half a gallon of crude oil or sump oil will aid in completely destroying a sheep carcase. Burial alone is of little real value in

fly control as flies are still able to emerge when buried several feet in loose soil. Burial after poisoning is quite satisfactory and for this purpose . arsenical < dip, or borax mixed with equal parts of dry sand or soil can be applied by means of a shaker. Spraying with a half per cent, solution of sodium arsenate is also effective. Poisoning as above, even without burial is useful if the carcase is turned and both sides dusted, paying particular attention to the mouth and tail regions where most of the eggs are laid. Disposal of Infested Crutchings The disposal of crutchings is much more important than carcase disposal, because in the case of crutchings every single maggot may develop into a fly which becomes a potential danger to sheep, while in a carcase these must compete against other species which rarely cause , fly strike. Crutchings should be, either , burned or poisoned with 1 per cent, arsenic. ~ One simple method, is to crutch the sheep on a square/ of strong canvas from which crutching and maggots can be easily collected and burned or poisoned. Treatment The treatment of fly strike involves the removal and destruction of the

maggots from the struck area. This is best effected by striking repeatedly close to the area with the flat of the shears and so jolting the maggots out of the strike. A suitable dressing is then applied. The perfect dressing which is nonirritant, promotes healing without excessive scab formation, is cheap and easy to apply and which will kill the maggots and repel the adult flies, has yet to be discovered, but the following preparations have proved very valuable in the treatment of strike. . 5 per cent, bluestone has been very popular but has the disadvantage that it stains the wool. 5 per cent, zinc sulphate is quite . as good and staining is avoided although neither of these preparations . penetrate the wool very easily. Dry boric acid dusted on the area is simple and effective. Glycerine diborate, C.8.E., and B. dressing developed by the C. in Australia are effective but at the present time the ingredients are either unprocurable or prohibitive in cost. The New South Wales Department of Agriculture recommends — 4 per cent, phenol crystals, in whale oil with or without the addition of 5 per cent, carbon tetrachloride as a repellant. A satisfactory dressing can be made as follows: — ' . , Zinc sulphate ....... 10 ozs. Powdered starch .... 4 ozs. Carbon tetrachloride 8 ozs. Water 7 pints ' The zinc sulphate is. dissolved in the water and . the starch added and gently heated until dissolved and the mixture becomes a watery. jelly. When cool the carbon tetrachloride is added and thoroughly mixed. . Another, satisfactory preparation can be made by substituting boric acid for zinc sulphate in the above formula. The application of dressings can be carried out effectively by the use of a brush which can be made by wiring horse hair. to a suitable handle about eight inches long and cutting off the hairs at a length of about four inches. Treatment should be carried out as early as possible. During a fly wave close supervision of the flock is essential and, if possible, struck sheep should be drafted into a hospital. paddock where, if necessary, they can be re-treated without yarding the remainder of the flock.