THE EFFECT OF CALCIUM SUPPLEMENT ON THE DIGESTION OF ORGANIC NUTRI-
ENTS IN FODDERS IN WHICH LIME CONTENT IS EITHER LOW OR HAS A
TENDENCY OF POOR ASSIMILATION
By RAMESWAR MUKHERJEE, M.Sc., Late Assistant Physiological Chemist and INDUBHUSAN CHAT-
TERJEE, M.Sc. (AGR.), L. Ag., Formerly Physiological Chemist, Department of Agriculture,
Bengal
(Received for publication on 27 May 1946)
T HE study of the possible effect of a deficiency or deprivation of mineral elements on the diges-
tibility and utilization of organic nutrients of feed does not seem to have received much atten-
tion. Ranganathan and Rao [1938] studied the influence of calcium intake and found that an in-
crease in the ingestion of calcium of rats improved both the digestibility and biological value of
protein. In similar experiment Swaminathan [1931] did not observe any effect of calcium intake
on the biological value of protein. Henry et al [1940] working on rats found the same value for the
biological value and true digestibility at two widely different levels of calcium ingestion, viz. 0.07
per cent and 0.86 per cent calcium. Earlier work of Woodman and Evans [1930] supports the find-
ing of the latter worker, and their results on sheeps showed that the digestibility of organic nutrients
was not affected by the deficiency of minerals (specially calcium and phosphorous) in the feed.
The investigation forming the subject matter of this paper arose from the following considera-
tion. A feeding and metabolic test was initiated with Napier silage which was however found to
be very poor in lime (0.29 per cent CaO on dry basis and 0.07 per cent on fresh basis). It should
be noted that Napier grass is the recommended fodder from Bengal Agricultural Department and
silage was made from this grass. The experiment was therefore designed with a view to see amongst
others how far the addition of calcium supplement given as CaCO 3 was likely to be reflected on the
digestibility of organic nutrients. This represented an experiment in which the fodder was admit-
tedly deficient in lime.
It has been found in a series of previous trials that the lime present in rice straw has a tendency
of poor assimilation. An experiment with Boro variety of rice straw with and without lime given
as CaCO 3 provided the material for studying their effect on the digestibility of the same nutrients.
EXPERIMENTAL
Both under Napier silage as well as Boro straw eight bullocks of approximately same age and
ive weight were selected four being placed under 'No lime' and four under 'Lime'. The animals
under 'Lime' were each given 25 gm. of CaCO 3 daily.
The Napier Silage was made at Dacca Farm silo pit and was fed ad lib. to all the eight animals.
Linseed cake at the rate of 0.5 gm. per lb. of live weight was fed as concentrate to the silage animals.
The animals were watered twice daily. The feeding lasted altogether for 50 days and the metabolic
collection commenced after 29 days and continued for 13 days.
In the case of Boro straw also it was fed ad lib. The concentrate given was mustard cake at
the rate of 10 per cent on the straw actually consumed. The feeding lasted for a total period of 83
clays and the metabolic collection commenced after a preparatory feeding of 59 days and continued
for 10 days.
In both the groups common salt was given at the rate of 25 to 40 gm. per animal per day.
RESULTS AND DISCUSSIONS
It should be noted that both these experiments have been recorded in the Annual Reports of
the Physiological Chemist, Bengal, for the years 1936-37 and 1938-39. A paper on the nutritive
value of Boro straw also forms the subject matter of a separate communication by Chatterjee and
Sarkar [1947].
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