1. Three different experiments in order to compare the nutritive value of
'good' and 'aid' silages made from the same material have been described.
In the first experiment a comparison between top and bottom samples taken
from a large farm silo showed that considerable variation in chemical
composition can occur throughout the mass. In two experiments carried out
using small experimental silos, silages with pH differences of 0.5 and 0.6
respectively were produced from similar grass material. There was little
difference in nutritive value between the high and low pH products in either
2. Two experiments were carried out in order to compare wilted grass
silage and ordinary grass silage. The wilted grass silages contained
slightly more sugars than the ordinary materials and were of slightly
higher pH. In the first experiment the digestibilities of the various
constituents were similar in the wilted and non wilted silages but in
the second experiment the wilted grass silage showed significantly higher
digestibility values for all constituents. The dry matter losses which
occurred during ensilage were of a similar order for both materials in
spite of the absence of effluent from the wilted grass silo.
3. Results for the composition and digestibility of the constituents of a medium -protein grass- clover mixture and of molassed and unrnolassed silages
derived from it indicated that there was little difference in nutritive value
and both types compared favourably with the original grass when cut in both
spring and autumn.
The losses occurring in the silages made from spring grass were of a very low order whilst those obtained in the silages made from autumn grass
showed losses of a greater magnitude; the unmolassed material showing the
highest loss. The addition of molasses to the ordinary silage at the time
of feeding did not markedly affect the digestibilities of the various
The losses encountered during haymaking from the spring grass by two
different methods illustrated the advantage that silage making had over haymaking in the efficiency of the conservation process. Tripoding had a distinct advantage over field curing in that a product of higher nutritive
value was obtained.
4. In a comparison of the nutritive value of spring and autumn grass cut
at a similar C.P. level, little difference could be detected in composition
or digestibility although considerable variation occurred in the utilization
of the total digestible nitrogen. The nitrogen in the spring grass was
more efficiently utilized by growing sheep than that in the autumn grass.
5. An experiment designed to compare the digestibility and nitrogen
utilization of dried grass when fed at two different seasons of the year to
growing sheep showed that neither season nor age of the animal had much effect
upon these values. The results showed there was a tendency for young
lambs (aged 9 months) to digest slightly less crude fibre than adult animals
although no significant difference in nitrogen utilization was detected.
6. A study of the results of 22 digestibility experiments on grass silages
ranging in C.P. content from 9.9 to 23.1 have been made and two different
of calculating the feed intake of animals on the 'self feed'
system have been compared. The value of C calculated by Lancaster's method
for animals consuming fresh pasture grass compared favourably with a similar value calculated for sheep on a silage diet. Equations have been
derived for calculating dry matter intakes by Lancaster's method and by a method involving the use of the C.P. content of silage.