80
ABSTRACTS
better gains and had much better appearance and a finer coat of hair than those of the
animals on corn oil and cocoanut oil. The females of each group were mated with the
males of the same group. Litters of butter-fat group were all normal and were raised
to maturity. The litters of the other groups were small and very weak. The mortality
was also high. No litters were obtained from the females of cocoanut oil group.
In the second observation, cotton seed oil and soyabean oil were included in the
feeding experiment. The arrangement of the experiment was exactly the same as in
the previous one. The difference in the growth rate appeared most noticeable during
the first three weeks both in the males and females. The gains made by the rats on
butter-fat group were 22 per cent greater than that on corn oil, 23 per cent than that on
cocoanut oil, 14 per cent than that on cotton oil and 26 per cent than that on soyabean
oil. The fertility showed no change from that which was observed in the first experiment.
In another experiment, the authors tried to ascertain whether the saponifiable
or the non-saponifiable fraction of butter-fat was responsible for the better growth and
improved reproduction. The diets containing the vegetable oils were supplemented
with the non-saponifiable fraction of butter-fat and the animals were treated exactly
in the same manner as in the two previous experiments, that is, records of growth, general
health and reproductive power were studied. The animals on supplemented diets showed
no better response than those fed on vegetable oils without the non-saponifiable fraction.
Growth and general health were practically the same and there was considerable diffi-
culty in raising the pups on supplemented diet, though the animals were receiving all
the factors for reproduction. The authors concluded that the factors responsible for
the better growth and reproduction lie in the saponifiable fraction of the butter-fat.
[D. N. M.]
The length of time required for depletion of vitamin A reserves in range
cattle, J. K. RIGGS (1940). J. Nutr. 20, 491-500.
A N experiment was designed to record the length of time required for the deple-
tion of vitamin A reserves in two hundred and seventy range cattle of varying ages.
The calves ranged in age from 3 to 8 months and in. weight from 225 to 467 pounds.
The yearlings were approximately 16 months old and averaged 559 pounds in weight.
Complete depletion was measured by observing the progressive nature of night blind-
ness in all the animals. The observation consisted in driving all the animals in a court
yard having a series of obstacles and noting the peculiar movement of the animals imme-
diately after twilight; when the animals were completely nightblind, they tumbled
against the obstacles.
The animals were grouped according to age and the nature of the ration fed. The
first group consisted of 48 steer yearlings and were on a ration containing 12 per cent
cotton seed meal, 88 per cent cotton seed hulls and salt ad lib. The time required for
depletion ranged from 128 to 266 days with an average of 178 and a standard deviation
of 37. The second group of 40 steer calves received a ration composed of 3 per cent
tankage, 10 per cent cotton seed meal, 87 per cent cotton seed hulls and salt ad lib. The
depletion time ranged from 101 to 206 days with an average of 136 and a standard devia-
tion of 25. Fifty steer calves were in the third group and were on the same ration as
fed to the second group. The depletion time ranged from 96 to 194 days with an average
of 138 and a standard deviation of 21. The fourth group consisting of 50 steer calves
received the same ration as taken by the second and third groups of animals and deve-
loped night blindness within a period ranging from 82 to 155 days with an average of
107 and a standard deviation of 21. The age of the animals of the 2nd, 3rd and 4th
groups varied from 6 to 8 months and that of the 5th and 6th groups of animals varied
from 4 to 6 months and of the 7th and 8th groups from 3 to 5 months. Groups 3 and 4
were fed limestone flour at the rate of 0.1 pound per head daily. The fifth group of
30 heifer calves received a ration having in it 3 per cent tankage, 15 per cent cotton
seed meal, 30 per cent sorghum grain, 50 per cent cotton seed hulls, 1 per cent limestone
flour and 1 per cent salt. Depletion time varied from 82 to 112 days with an average
of 98 and a standard deviation of 7. The ration of the sixth group of 10 steer calves
comprised 13 per cent cotton seed meal, 38 per cent sorghum, 49 per cent sorghum fodder,
limestone flour and salt ad lib. The time required for the depletion of vitamin A reserve