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INVESTIGATIONS ON TRACE ELEMENT (COPPER) I. [Vol. XXI, Part IV
lambs, enzootic in certain parts of western Australia, was associated with a defi-
ciency of copper in the mother and could be avoided by treating the ewes with copper
during the period of gestation. Confirmation of their discovery has been reported
from South Australia by Bull et al. [1938] and from England by Dunlop and Wells
[1938], where a similar malady known as 'swayback' occurs in certain restricted
areas. An account of depigmentation, a new dietary deficiency disease, as cured
by copper has been given by Gorter [1935] and Mc Collum et al. [1939].
Adequate amount of copper in the diet has been reported by Black et al. [1937]
to show a more efficient utilization of food, greater weight gain, greater energy
storage and greater accumulation of fat and protein. In larger doses copper is
extremely toxic and heavy losses due to copper poisoning have been reported by
Boughten and Hardy [1934] and Eden [1940]. The toxic level, however, has been
reported by Eden [1940], and Pullar [1940] to vary with the type of diet as also with
the species.
The above observations clearly show that copper occupies a very important
place in the group of 'trace' elements which are essential for animal life.
In view of the fact that there is almost a complete lack of information on the
significance of trace element, copper, in the nutrition of animals in India, where
livestock play an important role in the agricultural economy, a systematic investi-
gation on copper in relation to cattle nutrition was undertaken in these laboratories
in 1944.
The study of the nutritional role of an element necessitates primarily a know-
ledge of its distribution in biological materials. The information on the copper
content of biological materials is on the whole, meagre and whatever is available
relates to foreign countries. It has been observed by Kehar and Momin [1950]
that climate, soil and environmental conditions exercise a great influence on the
chemical make up of feeds. The frequent data can, therefore, be of little value in
providing accurate information. The present paper, therefore, which is the first
of a series, has been devoted to the study of the copper content of cereal straws,
grasses, leafy fodders, cultivated plants, grains, seeds and their by-products and
also the different organs and blood of normal animals.
The feeds for analysis were either obtained from the Institute Estate or a
nursery of the Forest Department in Clutterbuckganj about four miles from this
Institute. Some of the samples were procured from the market. The blood and
tissues for analysis were collected from the normal animals.
EXPERIMENTAL
The method used for the estimation of copper is a slight modification of Eden
and Green [1940] which is based on the diethyl—dithiocarbamate method of Callan
and Henderson [1929]. The salient features of the method used are as follows:
One gm. of the dry material (1-5 gm. of wet tissues or 5 ml. of blood) is taken
in a pyrex test tube, 200 mm. × 25 mm. 1.5 ml. of A. R. sulphuric acid, 2 ml. of
70 per cent Bakers Analysed perchloric acid, 1 ml. water and two glass beads are
added and, the mixture heated over the lowered flame of a bunsen burner. Heating
is continued until an almost homogenous dark brown liquid is obtained. The tube