92
The Value of Boro Rice Straw as a Cattle Feed
the nutritive ratio given in Table III rather suggests that for the purpose of maintenance, concen-
trates can be completely dispensed with. This is however not advisable as it has been found in other
experiments that when rice straw is fed without concentrate it adversely affects economic utili-
zation. But the quantity can be safely reduced to half or possibly even less. A careful feeder can
adjust it after watching the effect on the animal for a short period.
NITROGEN AND MINERAL METABOLISM.
As all the figures connected with above will occupy large space only the digested share in the
case of nitrogen and total intakes in the case of minerals are set up in Table V.
TABLE V
Digested nitrogen and total intake of minerals
Particulars
No lime Straw and Mustard cake
Lime straw and Mustard Cake
Animal
D3
D4
D7
D9
D1
D2
D6
D6
Live
weight
753
778
661
712
717
757
766
649
Digested
nitrogen
55.40—
55.52 +
47.39 +
48.04 +
45.24 +
44.47 +
55.97 +
47.12 +
Computed on 500 lb. live weight
CaO
13.65—
12.82—
13.93—
13.46
12.65—
11.74 +
14.08—
13.81—
Mg.
11.82 +
11.10 +
12.06 +
11.65 +
10.95 +
10.17 +
12.19 +
11.96 +
K 2 O
73.86—
69.36-
75.35—
72.81—
68.45—
63.50—
76.17—
74.74—
Na 2 O
3.38 +
3.18+
3.45 +
3.34 +
3.14 +
2.91 +
3.49—
3.42+
P 2 O 5
11.42 +
10.73—
11.65—
11.26 +
10.59 +
9.82 +
11.78—
11.56—
Cl
18.47—
17.34—
18.84—
18.20—
17.11—
15.88—
19.04—
18.68—
*The symbols + and — indicate whether the balance was positive or negative
In Table V the positive and negative symbols have been put to indicate whether the balance
was in favour or against. The significant feature is that lime balance has been invariably negative
in spite of feeding calcium carbonate. The magnesia balance has been positive and it does not call
for any comment. The negative potash metabolism under rice straw and mustard cake has been
generally a common feature and this is corroborated here. The ingestion of phosphorous has been
nearly double the requirements and more than half of it has come from the share of Boro straw.
The balances have been 50:50 positive. This also points to previous indications that the phosphorous
of rice straw is of doubtful utility. Soda and mitrogen have been all positive under 'No lime' but
under 'Lime' group one has recorded negative balance for soda and another for nitrogen. The
addition of lime has not contributed favourably. It has been already noted that it has also depressed
the availability of T. D. N. and starch equivalent. It has been found in many experiments here
that the lime requirement under rice straw is always high. In a previous paper by Carbery,
Chatterjee and Talapatra [1937] it was stated on the basis of experiments on Aus straw that the
lime requirement per 500 lb. live weight is about 24 gm. CaO. The negative values in the cake of
Boro straw even when the ingestion was over 29 g.m. suggest that the requirement under this straw
is still higher. It is difficult to say what are the contributory causes. The potash content in this
straw is high, but similar amount is found in the other straws also. It however contains a very large
amount of oxalic acid as can be seen from the following table.
TABLE VI
Oxalic acid content of different straws
Laboratory No. of the
straw
61/1939 . . .
62/1939 . . .
47/1936 . . .
Straw
Amon straw, Dacca .
.
.
.
.
.
Aus straw, Dacca
.
.
.
.
.
.
Boro straw, Dacca .
.
.
.
.
.
Oxalic acid
crystal
per cent
0.662
0.646
1.496
Lime
equivalent
to oxalic
acid
per cent.
0.294
0.287
0.665
Actual lime
(CaO)
per cent
0.425
0.643
0.343