264
The Nutritive Value of Alkali-treated Cereal Straws
soaking could be cut down considerably without interfering with the full
effect of the alkali on the straw. Other alkalies, besides caustic soda, such
as sodium carbonate and lime, were successfully used in treating the straw,
though in some of these cases, it was found necessary to resort to heat treat-
ment. Schorger [1926] has discussed in detail the various methods of alkali
treatment and the resulting chemical and nutritional changes in straw studied
up to the year 1926.
In the progressive agricultural areas of the world, cereal straws do not
constitute a large part of the rations of livestock in normal times. Under
war condition, however, when transport facilities are seriously affected
and grass lands are ploughed up for human food production, a comparatively
large amount of the energy requirements of farm animals can be obtained from
feeding stuffs which are always at hand, such as cereal straws. At such
times, any process which can enhance the nutritive value of straws is well
worth our consideration. The present war has brought about a renewed
interest amongst the British workers in the alkali treatment of straws. Thus
Slade, Watson, and Ferguson [1939] pointed out that by soaking oat straw
and wheat straw for 24 hours at ordinary temperature in 8 times its weight
of 1.25 per cent caustic soda solution and subsequently washing it, a marked
rise in the starch equivalent was obtained. Using a similar method recom-
mended by the Imperial Chemical Industries Ltd. for treating straw with
1.5 per cent caustic soda, controlled feeding work with treated wheat straw
has since been carried out under the auspices of the Ministry of Agriculture
and the Agricultural Research Council at five centres in England and Wales,
the detailed results of which are now available (Journal of the Ministry of
Agriculture, 1941, vol. 48, p. 85). In three out of these five centres, the results
obtained were definitely satisfactory. It was shown that with a total of
31 pairs of steers and heifers during an average experimental period of 71
days (half the animals being kept on treated straw and the other half on
untreated straw with the same basal ration) the average gains in live weight
were 0.99 lb. and 1.65 lb. per day for the untreated straw-fed and treated
straw-fed groups respectively. The growth in the animals of the treated
straw-fed group was thus about 65 per cent more than that in the other group.
The results obtained in the other two centres were not very encouraging and
the failure to obtain good results were ascribed to two reasons :—
(a) the unpalatableness of the treated straw and (b) the experimental
animals were somewhat advanced in age as compared with those in the other
centres and thus would be unlikely to show much change in weight. Based
on the general findings, however, the Ministry of Agriculture has advocated
a wider use of the alkali-treated straw for feeding livestock in the British
Isles.
A simple, practical method of improving the nutritive value of straw
would nowhere be more welcome than in India. According to a recent pub-
lication [Sen and Ray, 1941], the straws constitute by far the largest amount,
about 80 per cent of the total organized roughage supply for the cattle of
India. A special position is occupied by paddy, which is grown in about
25 per cent of the total cultivated area devoted to human food crop produc-
tion, and this straw forms the staple food for the great majority of cattle in