ABSTRACTS
175
Component acids and glycerides of some Indian ox depot fats. T. P. HILDITCH
AND K. S. MURTI. (1940). Biochem. J. 34, 1301.
F OUR widely selected ox depot fats were examined, viz. those of a cow and bullock in
Bombay, that of a cow in Calicut and a mixed sample from both sexes from Calcutta.
The individual samples were probably taken from more than one animal. They were
reasonably regular in melting point of fat and of fatty acids but the iodine value of the
Bombay fats was much lower (26) than that of the other samples (31). The samples
had developed free acidity before analysis and the neutralised samples only were analysed
for component fatty acids and component glycerides by the methods usually adopted
at the Liverpool laboratories, after preliminary fractionation by crystallization from
acetone at low temperatures.
Oxen in the Bombay area are fed on grass, jowar, wheat, bran and cottonseed while
the main diet of the Calcutta and Calicut animals was grass and paddy straw. This
difference in food was the major cause of the different compositions of the depot fats.
All the depot fats examined were much more saturated than those of European
and American animals, and contained only 27-33 per cent of unsaturated acids (mainly
oleic) (English, 35 per cent oleic). The stearic acid content did not exceed 26-28 per
cent; the palmitic acid was generally higher than the 30±3 per cent hitherto con-
sidered characteristic of ox fat. In the sample from the Bombay cow, palmitic
formed over 40 per cent of the total fatty acids. The presence of larger amounts of
palmitic caused the melting point of the fat and the solidifying point of the fatty
acids to be the same as for ordinary ox fats.
The component glycerides of two cow fats studied in detail were found to conform
in structure to other ox depot fats. The larger amounts of palmitic acid was reflected
in increased amounts of dipalmito glycerides, but the amounts of monopalmito glyce-
rides were comparable to those in other ox depot fats after allowing for the more highly
saturated nature of the fats.
[W. L. D.]
Studies on the secretion of milk fat. 3. Effect of thyroxine administration
on the blood lipoids and on the nature of milk fat. J. A. B. SMITH
AND N. N. DASTUR. (1940). Biochem. J. 34, 1093.
P REVIOUS experiments by others have shown that the feeding of dried thyroid gland
to cows or the intramuscular injection of thyroxine raises the milk yield and the
percentage of fat and solids not fat in the milk, and lowers the fatty acid but raises the
sugar content of arterial blood.
Four cows in the present investigation were injected intramuscularly with 10 mg.
thyroxine daily for a 10-day period ; the milk was sampled and weighed before, during,
and after this period. The milk yields of all cows were increased greatly during and
for 3 days after the thyroxine period ; of the milk constituents only the fat showed a
slight increase due to thyroxine treatment in 3 cows while a small rise in lactose was
evident in the milk of the fourth animal. These results generally fail to confirm pre-
vious findings of raising the solids not fat content of milk by thyroxine treatment.
A detailed study of the daily change in the composition of the fat was made (Reichert
and iodine values). It is unfortunate to observe that the composition of the fats from
the milk of 3 cows was abnormal in the control period (Reichert, 18 to 26, iodine value
44 to 54). The fat from one of these cows, examined in detail showed a Reichert value
of 17.2 and an iodine value of 48.4 after thyroxine treatment, but values of 16.8 and
46.5 respectively 15 days after the end of that period. These butterfats had high oleic
and palmitic but low butyric, myristic and stearic acid contents.
The sugar content of blood plasma was increased by some 10-26 per cent and the
main lipoid constituents decreased by 10-20 per cent during the period of thyroxine
treatment.
[W. L. D.]