I. B. CHATTERJEE AND S. N. SARKAR 93
The above results show that the oxalic acid present in Boro straw is considerably more than in
Aus and Amon straws and further that it is theoretically capable of rendering insoluble nearly twice
the amount of lime actually present. Recent work by Talapatra et al [1942] suggests that the soluble
oxalic acid is probably largely decomposed in the reumen. Nevertheless the presence of a large
amount of a substance which is both toxic and precipitant of lime is an unsatisfactory feature. The
experiment suggests that the lime requirement per 500 lb. live weight under Boro straw is highest
(not less than 30 gm. CaO), Aus comes next with 24 to 25 gm. CaO and Amon still less (about 18 to
20 gm.).
If we leave aside the unsatisfactory behaviour of lime metabolism as well as the high content
of potash and oxalic acid, this straw like Aus variety is superior to Amon. Moreover it is the richest
amongst all the rice straw varieties in protein content and in this respect it is even superior
to Aus. It has been already pointed out that this straw contains a large percentage of insoluble
siliceous matter. It means that a very large ingestion of such material is inseparable with its feeding.
The trial which was conducted for a few weeks does not permit any inference as to how far a
continuous feeding of this nature can have a cumulative effect.
It should also be stated here that the animals were fed sodium chloride at the rate of 25 gm.
of sodium chloride per animal. There was no reason for a deficiency of chlorine. In spite of it there
has been a negative balance, which apart from this trial has been noticed in the experiment with
a few of other samples Amon rice straws obtained from the different soil belts (specially the saline
tracts). At present no explanation can be offered for such a phenomenon.
SUMMARY
1. The feeding value of Boro variety of rice straw has been investigated and comparative data
have been presented.
2. The experiment was conducted with 'No lime', and 'Lime'. The lime was given a
calcium carbonate. The feeding of lime did not offer any advantage. On the other hand there
was a depression of digestibility which was well marked in ether-extract and crude fibre, the former
also exhibiting great fluctuation.
3. The main feature of this straw is a large percentage (compared to other rice straws) of protein
content, a lower percentage of fibre, a very large percentage of insoluble silica and also a high per-
centage of oxalic acid.
4. Like Aus rice straw, Boro rice straw is definitely superior to Amon rice straw in its nutritive
value on the organic side. As it contains the highest percentage of protein compared to the other
two straws, it definitely economises protein requirement and from that standpoint is superior even
to Aus straw.
5. Its unsatisfactory feature is that, its oxalic acid content is highest for which its lime require-
ment is highest (amongst all rice straws); and for reasons still unknown the chlorine balance has also
exhibited a negative tendency besides lime, potash and phosphate which are usually so found in other
rice straws.
6. Further experiments are required to devise correctives for the unsatisfactory lime, potash
and chlorine metabolism as well as for high content of oxalic acid and also to see how the large quantity
of insoluble siliceous matter as found in Boro straws, is likely to react on the animal system specially
under a prolonged feeding.
REFERENCES
Carbery, M. Chatterjee I, and Talapatra S. K. (1937)
Studies on the mineral requirement of cattle in North East India with special reference to rice straw feeding. Indian
vet. Sci. 7155-211
Talapatra S. K., Roy S. C., Kehar N. D. and Sen K. C.(1942).
Oxalic acid in food stuffs. Science and Culture, 8209-213
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