K. C. SEN, S. C. RAY AND S. K. TALAPATRA 295
can be made softer to the feel and finer in texture than the raw material from
which they were produced. Williamson [1941] has published in a recent issue
of the Journal of Agricultural Science, the effect of alkali treatment on the
digestibility and feeding value of barley straw for horses. He has shown
that by treating the straw in ten times its weight of 1.25 per cent solution of
caustic soda for 12 hours and subsequently washing out the absorbed alkali,
the digestibility coefficient of N. F. E. and crude fibre can be increased from
33.23 to 54.14 and 38.24 to 63.71 respectively. The improved digestibility
resulted in the increase of S. E. from 5.53 lb. to 23.58 lb. per 100 lb. of the
dry material. The feeding value of barley straw for horses is thus remark-
ably improved by the alkali treatment. Furthermore, the palatability of
the straw was in no way affected by the treatment because the animals ate
the treated straw with ' apparent zest'.
During the course of the present investigation, a small quantity of dry
treated paddy straw was shown to a horse belonging to the Institute. The
animal seemed to relish this feed. Further work, however, is necessary
before any definite conclusion can be drawn regarding the suitability of
treated straw for feeding horses in India.
SUMMARY AND CONCLUSION
The composition of wheat, oat and paddy straws can be profoundly
changed by soaking them in the cold in a 1.25 per cent caustic soda solution
for 20—24 hours. By this alkali treatment of straws, the percentage composi-
tion of crude protein, ether extract, nitrogen-free extracts, ash, potassium,
phosphorus and chlorine is lowered and that of crude fibre, calcium, magne-
sium and sodium is increased. During the treatment, dry matter is lost to
the extent of 25 to 35 per cent.
It has been found that about 40 per cent of the alkali present in the
solution is used up after one treatment. By regenerating the strength of
the residual liquor with a suitable addition of caustic soda, two more batches
of straw can be treated with good results.
Digestibility and metabolism experiments carried out with wheat and
paddy straw on Sahiwal heifers show that the digestibility coefficient of total
carbohydrates in either straw is markedly improved by the alkali treatment.
This also increases the S.E. value of wheat straw from 21.3 lb. to 34.1 lb.
and that of paddy straw from 24.4 lb. to 35.9 lb. per 100 lb. of dry material.
The nitrogen, calcium and phosphorus balances are considerably improved
when the animals are fed on the treated straws.
The alkali treatment has a special significance in the case of paddy straw.
It appears to remove some of the factors which affect the absorption and
utilization of nitrogen, calcium and phosphorus from rations containing this
straw.
The increased nutritive value and the better physical texture brought
about by the alkali treatment suggest that the treated straws can be used
in place of poor quality average hay in the feeding of horses.
From a comprehensive study of the problem of alkali treatment of cereal
straws, we have thus come to the conclusion that poor quality roughages
in India can be remarkably improved. The improvement lies in the better
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