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GROWTH PROMOTING VALUE OF OILS AND FATS [Vol. XX, Part III
in synthetic diets, wherein they found that the rats on butter and fatty acids of
butter grew better. Euler et al. [1942] proved that in presence of vitamins lard
was superior to butterfat in growth promoting properties. Recently Henry et al.
[1945], compared the growth promoting properties of butterfat, margarine and
other vegetable oils in skim milk and in dry basal diet, and, concluded that
there were practically no differences in the different fats, so far as their nutritive
properties were concerned. Basu and Nath [1946] also compared the nutritive
values of different fats and oils and observed a better growth with butterfat than
with the other fats. Thus, it is seen that no definite conclusion has been reached
with regard to growth promoting values of different fats. It was, therefore, thought
of interest to study the comparative growth rate of rats on various fats and oils and
the results of the experiment are reported in this paper. A study was also made
on the nutritive value of vanaspati (hydrogenated oils) over second and third
generations of the rats.
Collection of the fats used for the experiment
Samples of genuine ghee from eight different breeds of cattle, viz. Sindhi,
Kangayam, Ongole, Gir, Kankrej, Sahiwal, Hariana and Murrah buffaloes were
collected from the dairy farms at Housur, Madras, Charrodi, Karnal, Hissar,
Montgomery (now in Pakistan), Delhi and Bangalore through their respective officers.
Goat ghee was collected from the farms at Hissar, Agra, Trichur, Anand, Chikkodi
and sheep ghee from Montgomery (now in Pakistan), Anand, Sanand and Togh
(Kohat now in Pakistan). The sample of vegetable oils and body fats were obtained
from Madras, Bangalore, Allahabad, Calcutta, Kanpur and Lahore and Karachi
(now in Pakistan) through the Agricultural Marketing Adviser to the Government
of India. The hydrogenated edible oils from groundnut, cottonseed and sesame
were obtained through the Vanaspati Manufacturers Association, Bombay. All
the fats and oils were stored at a temperature of about 45°—50° F. After determin-
ing their chemical composition, representative mixtures of all the different fats
except the hydrogenated samples were made and used for the growth experiments.
EXPERIMENTAL
Each of the fats was incorporated at a 5 per cent level in the diet otherwise
adequate for growth. Vitamins A and D were supplemented in the form of ether
extracts of the unsaponifiables prepared from codliver oil and mixed with the fat
before mixing with the other components of the diet. Vitamin A content of the
cow ghee was determined by Carr-Price reaction using Lovibond tintometer, and
was found to be 24 B.U. per gram and the vitamin A content of the other fats was
adjusted to the same level by adding adequate quantity of the codliver oil extract.
The vitamin A content of the cow ghee samples was checked occasionally and the
vitamin A level of all the fats adjusted to the same level, during the experimental
period as and when the diet was newly prepared. Attempts were not made to
equalise the vitamin D content of the various fats. Vitamin B complex was supplied
through yeast. The fats studied were divided into 2 batches, cow ghee was taken
as standard for comparison.