SILAGE INVESTIGATIONS AT BANGALORE                  267

It is very remarkable that in the present experiment it has been observed that
all the organic acids present in the green plant are entirely volatile, only three bags
showing the presence of non-volatile acids as well. On ensilage, however, enor-
mous quantities of non-volatile acids are produced in all bags. This distribution
of organic acids in the green plant is not in agreement with the former observa-
tions. There, a large amount of non-volatile organic acids which was present
before ensilage was lost during ensilage.

Essentially, it is the nature and extent of the organic acids produced that de-
termines the quality of silage which results. It has been stated by the Cambridge
workers that a greater production of non-volatile acids than volatile ones is essen-
tial for the silage to be of good quality. This has been found to be quite unneces-
sary by all workers in India and this experiment is a further confirmation of the
same. Table XX shows that, except in two cases, the ratio is greater than unity ;
nevertheless the resultant silage has been of excellent quality. What seems to be
the deciding factor is the nature of the volatile acids produced. The absence of
butyric acid is essential for the silage to be good. In the experiments conducted
here no butyric acid, at least not sufficient to be identified, was observed.

                                D. Changes in the Carbohydrates.
Over 80 per cent. of the dry matter of plants consists of carbohydrates. It is
at their cost that the main bacterial activity goes on during ensilage and hence
they suffer the largest losses. The changes in this group of substances could be
more easily dealt with under the following three heads :—

    (1) Changes in the Nitrogen free Extractives.—Evidently the soluble carbohy-
        drates would be the first to suffer loss due to bacterial action, as they
        are the most easily attacked. As has already been stated, the end
        products of bacterial action on this group of substances are organic
        acids, CO₂ and H₂O. The first has already been considered, the second
        escapes and the last is absorbed by the silage. The loss of N-free ex-
        tractives as seen from Tables XII to XV is 14.4 per cent., 12.0 per
        cent., 31.1 per cent. and 20.3 per cent., respectively, in pits 1 to 4.
        Evidently rapid filling accounts for the greater losses in pits 3 and 4.
        This is probably due to the large bulk of enclosed air, resulting from
        insufficient packing, stimulating destructive bacterial and other
        changes. Watering also increases the loss, though to a smaller
        extent.

    (2) Changes in Crude Fibre.—Crude fibre is always broken down to vary-
        ing extents during ensilage. The losses noted here are not very high,