Abstract:
Proc. Aust. Soc. Anim. Prod. (1978) 12: 271 THE USE OF PHENOL TO COMBAT FLY STRIKE AND WOOL BLINDNESS M.S. PRATT* and P.S. HOPKINS+ The blowfly is still a major cause of economic loss to the Australian wool industry. In wethers and rams this loss is largely due to pizzle strike and the recurrent costs of the husbandry methods used to control it. Current research with phenol used to produce a permanent bare area of skin around the prepuce of male sheep is the main theme of this paper. Data presented herein update the previous communications of Pratt and Hopkins (1976a, 1976b). A film shown-in conjunction with this paper illustrates some of the practical aspects of treating sheep with a 40% phenol solution. The thickened and dyed solution is applied to a 4-8 cm wide strip (depending on the animal's size) surrounding the prepuce by means of a roll-on applicator. Healing of the destroyed skin in 6-8 weeks results in a bare area 5-8 cm diam, around the prepuce. The size of the bare area depends on the size of the prepuce and the degree it is flattened as a result of the treatment. Of the twelve thousand sheep treated throughout Queensland, the best results have been achieved on 3 - 10 month old weaners. Observations indicate that preputial flattening is not detrimental to the mating ability of rams. Benefits not included in the film are the low incidence of cut pizzles at shearing and minimum of stain in the belly wool. Chemical mulesing is not recommended in favour of conventional mulesi,ng, however, it does have application for removing the wool bearing skin between the previously mulesed area and the udder. This result affords the ewe extra protection from blowfly strike at lambing when afterbirth may adhere to the wool above thie udder and attract blowflies. A treatment of the jowl area shown in the film can also be effective in preventing wool blindness as the margin of the wool line is moved away from the field of vision. Phenol is toxic if animals are overdosed particularly if they are in poor condition. The chance of operator injury is minimised when protective glasses are worn and where any phenol splashed on the skin is immediately washed off.. In addition, the phenol solution should be thickened and dyed and applied with a roll-on applicator. The low cost of the treatments and their application by station labour at times of existing management procedures (weaner crutching or shearing) provide a cost saving to the wool industry. The commercial availability of the product depends on current trials throughout Australia. PRATT, MS. and HOPKHNS, P.S. (1976a). _ Proc. Aust. Soc. Anim. Prod. &&: 189. PRATT, M.S. and HOPKINS, P.S. (1976b). Wool. Tech. and Sheep Breeding * Qld. Dept. Primary Industries, Goondiwindi, Q. 4390. 4823. + Qld, Dept. Primary Ind,, 'Toorak' Res. Stn. Julia Creek, Q-