194 Journal of the Department op Agriculture. 



Pica Survey. 



The term "pica" in the ordinary dictionary sense means a 

 depraved appetite of any sort and of any origin. There are various 

 forms of pica which is found in the human as well as in the animal. 

 As to the latter it is well known that over large areas of South Africa 

 cattle show an abnormal craving, particularly for bones, being indeed 

 of such common occurrence in some districts that it is becoming 

 accepted by farmers as a natural feature in their animals. In some 

 districts the craving is mild, while in others it becomes so acute that 

 cattle are found to gather around the homestead or the hut, devour 

 washing, bags, clothes, riems, skins, and miscellaneous rubbish, and 

 persistently return when driven away. At present abnormal craving 

 is regarded as a nervous disorder and its vagaries are many, for the 

 best-conditioned animals are usually those which show the worst 

 craving, and as their condition falls off their craving abates. While 

 the Department possesses a degree of information on pica and its 

 relation to the lack of phosphorus in the pasture, there is need for a 

 much extended knowledge of an occurrence which may have a direct 

 bearing on many of our animal diseases. The investigations into 

 the disease of lamziekte and the discovery of Sir Arnold Theiler that 

 it is connected with a craving for bones on the part of animals in 

 certain areas of the Union, have convincingly proved the extreme 

 importance of pica in the causation of one at least of our dreaded 

 diseases, and it is considered that the time has arrived when a com- 

 prehensive survey of the Union should be undertaken Avith a view to 

 ascertaining the districts in which pica exists and the connection 

 between this craving and the various types of veld found in the 

 Union. It is known, for instance, that certain differences in regard 

 to pica in its relation to lamziekte exist on the various types of South 

 African veld, such as sour grass veld, sweet grass veld, etc., but 

 what these differences are and what they have to be ascribed to is at 

 present unknown. The matter is of great importance to this country, 

 and in order to clear up the problems surrounding pica it Avill be 

 necessary to consider all factors bearing on the chemical composition 

 of the pasture, the veld flora, soil composition, and the behaviour of 

 animals towards bones. 



The question has been before the Government, and the Minister 

 of Agriculture has approved of what is to be known as the " Pica 

 Survey " being undertaken in all parts of South xifrica and under 

 all possible conditions. The survey will include (1) the actual pica 

 test, i.e. the bone-eating test on the cattle present on the farm; (2) 

 a chemical analysis of representative samples of the pasture, collected 

 at different periods of the year; (3) a botanical survey of the area, 

 in order to establish definitely the differences between the various 

 types of veld ; and (4) a soil survey of the farms on which the tests 

 are carried out. 



The data which will be collected as a result of the Pica Survey 

 will undoubtedly be of the utmost value in the further study of animal 

 diseases in South Africa, more especially that group of diseases which 

 the farmer, since early times, has vaguely associated with the veld. 

 And not only in this direction will benefit follow, for it can reason- 

 ably be expected that the work will be of Aalue to other branches of 

 science as well. The Department is in the fortunate position of being 



