CHAPTER XXIII 



SHEEP DIPPING TANKS 



TnE circular sheep dipping tank about to be described is of a type which 

 has proved satisfactory in Australia (see the Journal of the Department 

 of Agriculture of Victoria, August 10th, 1910, pages 538 and 539). The 

 inslide and decoy pen have also been thoroughly tested, and are in 

 common use in that country. The Department of Agriculture of the 

 Union of South Africa recommends this form of tank in preference to 

 any other, because it is cheaper in construction ; it is economical in the 

 consumption of dipping material; and it will give better results with 

 much less labour in dipping operations, because the sheep can be kept 

 swimming throughout the full period of its immersion, which has a 

 beneficial effect in that, by the movements of the sheep in swimming, its 

 fleece is opened and the dipping mixture has an opportunity of penetrating 

 to the skin. With the long narrow tanks usually found in South Africa 

 such a course is not possible, because it only takes a sheep from half a 

 minute to a minute to swim through, when it must either be pushed or 

 held back in order to keep it immersed for the two minutes required by 

 law. This pushing or holding back involves a great deal of labour, and 

 when more than one sheep is placed in the tank at a time, as is generally 

 done, the animals climb on top of one another, and can only be held back 

 and immersed with extreme difficulty. The shoulders and backs of the 

 sheep, being out of the dipping fluid most of the time, are not properly 

 saturated, and thus the operation is ineffective. If the sheep are allowed 

 out before the two minutes expire, scab will not be cured. 



A circular tank, similar to that described in the following pages, was 

 erected, under the supervision of the author, at the Experimental Farm, 

 Potchefstroom, in conformance with the requirements of the Sheep 

 Division as stated by Mr. B. G. L. Enslin. 



The tank is supplied with a receiving yard, forcing pen, entrance 

 race, inslide, outslope, dripping pens, and a drying yard ; there is also 

 a decoy pen for the purpose of helping to get the sheep on to the 



