ORIGINAL ARTICLES

           THE NUTRITIVE VALUE OF ALKALI-TREATED CEREAL
                                               STRAWS

                                                   BY

                                              K. C. SEN

                                              S. C. RAY

                                                  AND

                                      S. K. TALAPATRA

Animal Nutrition Section, Imperial Veterinary Research Institute, Izatnagar

                    (Received for publication on 3 August 1942)

                                  (With one text-figure)

THE problem of a better utilization of crude fibre from coarse feeding
stuffs has for long been a subject of study and, some years ago, Mangold
[1934] drew attention to the number of attempts made by German workers
to treat straw by chemical and other methods so as to increase its digest-
ibility and utilization. He mentioned the ' Lehmann process ' of alkali
treatment of straw which produced a substance of greatly increased
fibre digestibility. In Lehmann's process [Lehmann, 1900] 200 lb. of
straw were boiled in large iron boilers with 40 gallons of water con-
taining 4 to 8 lb. of caustic soda for six hours at a pressure of four to five
atmospheres. After this, the product was washed with water until free from
alkali and then well pressed. By this process, the digestibility of straw was
found to be increased by about 50 per cent. Although the commercial utiliza-
tion of this and other similar methods eventually proved to be too expensive,
a large-scale production of treated straw was attempted in Germany during
the last war when an acute fodder shortage was experienced. In England,
Godden [1920] tried to simplify the process by soaking chopped straw over-
night in a 1.5 per cent solution of caustic soda. The treated straw was then
removed and the excess of caustic soda allowed to drain away, after which
the material was placed in a vertical container and heated in a current of
steam, the whole mass being kept at boiling point for about an hour. The
substance was then allowed to cool and the condensed water drained off.
During the steaming, sufficient organic acids were liberated from the straw
to neutralize the absorbed alkali and consequently no further washing was
required. With this treatment, Godden showed that the digestibility co-
efficient of crude fibre in oat straw increased from 60.1 to 87.4 and that of
nitrogen-free extract from 39.6 to 62.9. The consequent starch equivalent
(S.E.) value was found to increase from 20.6 in the original straw to 36.9
in the treated straw. During the treatment, however, 20 per cent of the dry
matter in the original straw was lost. When this loss was taken into account
the actual increase in S. E. proved to be about 43 per cent.

About the same time as this work was being carried out in
England, Beckmann [1919] in Germany introduced a new technique in
which no heat treatment was required. Furthermore, it was shown that
an alkali solution weaker than 1.5 per cent was effective and that the time of

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