K. C. SEN, S. C. RAY AND S. K.
TALAPATRA
265
India. Next in importance comes wheat straw, which is followed by some of
the millet straws. While, however, the quantitative supply of straws is vast,
the quality of this feed is poor. From many feeding experiments carried out
in this country, it is known that in paddy and wheat straw, the amount of
digestible protein is negligible and the essential minerals are poorly provided.
Moreover, though straws contain large amounts of energy-giving consti-
tuents, such as crude fibre and nitrogen-free extracts, only a small propor-
tion of these is actually utilized because of their poor digestibility. Thus
the only nutrient, namely energy, which is available from straws cannot be
supplied in an adequate quantity, because straws cannot supply more than
two-thirds of the actual energy even when consumed to the maximum extent.
Apart from this, it has now been shown by some workers [Carbery, Chatterjee
and Talapatra, 1937] that animals fed on paddy straw are usually on a neg-
ative calcium balance and that the level of calcium intake must be compar-
atively high with paddy straw to produce a positive retention of this mineral.
Experimental work carried out in our laboratory shows that a portion of the
calcium in paddy straw is in the form of calcium oxalate, the major part
of which cannot be metabolized in the body. The absorption of the rest of
the calcium in the paddy straw is further hindered by the large amount of
potassium which this straw contains. These factors, which are almost absent
in other cereal straws, makes the position of paddy straw unique from the
point of view of scientific study. Any treatment which can improve its
nutritive quality and remove its inherent defects must be considered worth
attempting at any time irrespective of whether it is war or peace.
The object of the present article is to describe the results of an investiga-
tion which has been going on for the last two years in this laboratory. Although
some of the early workers determined the digestibility of treated
straw, the recent work of the English investigators has been concerned with
feeding trials only. Our investigation has, however, been carried out in a
more comprehensive manner, so as to yield complete metabolism data regard-
ing two of our most important cereal straws and interesting results have been
obtained on the utilization of proteins, carbohydrates and minerals from rations
containing treated wheat or paddy straw.
EXPERIMENTAL
SECTION I. The effect of alkali treatment on the composition of cereal straws
Three kinds of straws, namely wheat, oat and paddy, were treated
in the laboratory with a dilute solution of caustic soda according to the
method suggested by Slade et al. [1939]. The object of the experiment was
to study the following aspects of alkali treatment:—
(a) the recovery of the dry matter after treatment, (b) the change in
the qualitative nature and the recovery of nutrients in the treated straws,
(c) the recovery of the alkali after one treatment and the possibility of its
repeated use for the same purpose. The detailed procedure of the experi-
ment is as follows :—
Representative samples of wheat, oat and paddy straws were obtained
from the Institute farm. They were chopped to about 1 inch in length.