Rothamsted Symposium on Trace Elements 120 



Sometimes, in a cow, a conditioned deficiency of copper is 

 accompanied by the well known symptoms of "pica" or "licking 

 sickness" just as those found in a case of real copper deficiency. 

 At other times, the "pica" symptom is only shown by an irregular 

 grazing of strip after strip, of the pastures, down to the roots. It 

 seems as if the animals were searching for something in the very 

 young blades of grass which they apparently miss in the older 

 blades. With horses, in normal condition, i.e., not suffering from 

 any deficiency, strip grazing of pasture may be frequently ob- 

 served. Real and conditioned deficiency of trace elements have 

 not been found in horses in Holland. 



It also happens that conditioned deficiency in cows is not ac- 

 companied by "pica" symptoms. Delayed growth of young ani- 

 mals occurs frequently, yet anemia, which, in this connection, is 

 regarded by some as an important symptom, is fairly rare. It seems 

 very questionable whether hemoglobinemia is connected with a 

 relative or absolute deficiency of copper. Exhaustion, scouring, 

 decreased output of milk, reduced appetite, white or greyish dis- 

 colouring of the coat, shedding of hair and a rough coat may, in 

 some years, be observed in various parts of the country. It 

 should be pointed out that in the examination of the coat some- 

 times grave errors are made. Frequently, the symptoms shown 

 by the coat, as the result from a delayed shedding of the winter 

 coat, are attributed to a copper deficiency. Sometimes, a con- 

 ditioned deficiency in copper is only shown by retarded growth of 

 young animals and the absence of heat, whereas the condition of 

 older animals is, on the whole, fairly sound. It may even be 

 observed that the symptoms of hypocupremia, which in some 

 years may be accompanied by a number of the clinical symptoms 

 mentioned above, in another year, though existent, leave the 

 animals in seemingly good health. This fact should make us 

 cautious in interpreting the chemical analysis. 



The great variety observed in Holland, with regard to the 

 clinical features of a conditioned deficiency in copper, presumably 

 also in other trace elements, renders it necessary to study the 

 causes of this variety. 



Are they mainly, or only, to be attributed to quantitative 

 differences in the amounts of copper and other trace elements? 

 The chemical analysis of the food, the blood and the liver of the 

 patients does not point in this direction. Or, does a certain indi- 



