June 1948] D. G. PANDITTESEKERE, S. C. RAY AND N. D. KEHAR 89
DISCUSSION ON RESULTS OF COMPARATIVE METABOLISM TRIALS IN EXPERIMENTS I A
Digestibility Co-efficient. The introduction of a small quantity of linseed-cake into the ration
had a profound effect on dry matter consumption and the digestibility of the whole ration, as also
of maize-husk determined by process of elimination. The average digestibility co-efficient data
summarized in Table X, show that the inclusion of the cake has improved the digestibility of crude
protein and ether extract of the whole ration; the carbohydrates moiety being relatively little in-
fluenced. The effect seems to be much pronounced in the case of maize-husk, all the constituents of
which have shown significantly higher digestibility in experiment II.
TABLE X
Digestibility co-efficient of the whole ration and maize-husk in Experiments I and II
—
Experiment I . .
Experiment II . .
Crude Protein
W. R.
41
53
M. H.
47
55
Ether extract
W. R.
28
62
M. H.
26
53
Crude fibre
W. R.
61
64
M. H.
61
76
N-free extract
W. R.
70
69
M. H.
74
79
Total carbo-
hydrates
W. R.
68
67
M. H.
72
79
W. R. —Whole ration
M. H. —Maize-husk
While it is desirable in determining the digestibility co-efficient of a test feed to reduce the associa-
tive effect of supplementary feed or feeds to a minimum, the co-efficient obtained of maize-husk under
a simpler dietary in experiment I cannot be accepted as representative in view of physiological dis-
turbances produced in the animals as evident from sub-optimal consumption and negative balances
recorded of the important nutrients.
Balances of nitrogen, calcium and phosphorus. The data on balances of N, Ca and P have been
summarized in Table XI. The supplementation of linseed-cake was responsible for the larger intake
of nutrients not only from its own quota, but also from wheat-bhoosa, the consumption of which was
stimulated by the inclusion of the cake in experiment II. The larger intake has a Salubrious effect
on the balances (Table XI).
In experiment I, nitrogen utilization was about 22 per cent negative as more nitrogen was excre-
ted in urine (10.17 gm.) than was absorbed (8.34 gm.), whereas in experiment II the utilization was
positive to the extent of 27 per cent. This result is in conformity with the finding of Morris and Ray
[1939] who showed no increased output of urinary nitrogen under conditions of phosphorus deficiency
as in experiment I.
According to Sen, Ray and Talapatra [1942], the requirement of calcium of adult animals of 300 lb.
body weight, fed on wheat-bhoosa and rape-cake, is easily met at a level of intake which is in the neigh-
bourhood of 6 gm. per day. Although the average intake of calcium in experiment I was 6.46 gm.
the balance proved to be significantly negative. This failure in the utilization can be ascribed to an
extremely low level of ingestion of phosphorus and consequent wide ratio of Ca/P.
The results of the balance experiments definitely indicate that the low phosphorus content in
maize-husk is a disturbing factor in its practical and economic utilization. The husk can be profitably
fed with a staple roughage like wheat-bhoosa if it is mixed with a small quantity of linseed cake in
the proportion of about 5:1.
E