14
Digestibility Trials on Indian Feeding Stuffs, XII
and the digestibility figures show that the total
carbohydrates and dry matter in taramira are
more digestible than those of sarson and toria,
while the digestibility figures of the protein are
much the same.
Linseed cake (Linum usitatissimum). This is
not generally favoured by Punjab zemindars, but
is extensively used in dairies and to some extent
in the north-east districts of the Punjab.
Groundnut cake (Arachis hypogaea). Groundnut
cake has only recently been introduced as a
feeding stuff in the Punjab, but it is not yet
extensively used, nor has it gained from stock
owners the recognition it appears to merit. It is
an excellent cake as regards taste and appearance,
and of all the cakes so far tested it is richest in
digestible proteins.
Oilseeds
Generally speaking, animals do not like oil-
seeds and perhaps this is why they are very rarely
fed to cattle. Taramira (Eruca sativa) seed, which
is distinctly pungent and has a very disagreeable
odour, was not liked by the animals, and they
fell off in condition; hence no reliable digestibility
data could be obtained with this oilseed.
Linseed (Linum usitatissimum) also was not
relished by the animals, and the consumption of
the basal ration, oat hay, was much lower in this
period than with other concentrates. Probably
its mucilaginous character adversely affected the
appetite.
Although linseed and sarson show identical
figures for digestible fat and total disgestible
nutrients, yet on account of its mucilaginous
character linseed is not comparable with sarson
and is rightly not used as a concentrate feed but
as a curative of digestive disorders.
Soybean (Glycine hispida), which stands in a
category by itself, has a very high digestible
protein content and a high digestible fat content.
It is relished by animals and does not cause any
digestive disturbances.
Grains, etc.
Guara (Cyamopsis psoralioides) is a leguminous
kharif crop, and the grain is usually fed instead
of gram, as it is cheaper.
Wheat mamni consists mostly of wheat screen-
ings and small wheat grain usually infested with
earcockle. It is very variable in character and
composition, but because of its cheapness it finds
favour with gawalas in towns.
Arhar (Cajanus indicus) is also a legume and
compares very favourably with gram, but has not
yet gained the recognition it appears to merit.
Moth (Phaseolus aconitifolius), rawan (Dolichos
lablab) and matri (Pisum sativum) are also legu-
minous grains and are used in times of scarcity.
All three are cheap sources of protein.
Oats (Avena sativa) is a concentrate of recognized
importance.
Chari (Andropogon sorghum) and bajra (Penni-
setum typhoideum) are non-leguminous grains,
common in the eastern and western Punjab.
DIGESTIBILITY DATA AND FOOD VALUES
The complete digestibility data obtained for
the digestible constituents of the feed, the
albuminoid ratio of the rations and the total
digestible nutrients for all feeds are shown in
Table IV: The figures are self-explanatory, and
there is nothing particular to which attention
needs to be drawn. A summary of the data pre-
sented is shown.
A point brought out in all digestibility trials
is that the data obtained for ash, digestible fibre
and nitrogen-free extract are likely to be mislead-
ing. As Maynard [1937] has pointed out some
of the absorbed minerals are excreted through the
gut, and there is no method of separating such
minerals from the portion which originally failed
to be absorbed. This being so, and as the re-
excreted portion may be large as well as a variable
part of the whole, it is obviously impossible to
arrive at a figure of any value for the digestibility
of most of the mineral elements. As Maynard
records, data for digestible ash, which are frequent-
ly reported in connection with digestion trials,
have no real significance. These facts have been
noticed during many years' experience of digesti-
bility trials at Lyallpur, and it has been decided
accordingly not to present these figures.
Another important point which experience with
feeding trials has emphasized is the difficulty of
obtaining reliable figures for the digestibility of the
fibre in feeds, such as oilseed cakes where the
fibre content is as a rule low. The digestibility
of the fibre in such cases is invariably masked by
the fibre of the basal ration and abnormal figures
are generally obtained. It is considered desir-
able, therefore, to group 'crude fibre' and 'nitrogen-
free extract' together as 'total carbohydrates ',
a procedure which has also been followed by
Watson and his colleagues [1939]. This procedure
gives more satisfactory results and does not affect
the figures for the total digestible nutrients or
starch equivalents.
In the past it has been a common practice with
research workers to work out the net energy values
from the ascertained starch equivalents in a
ration. Modern practice, however, is discarding
this, and as Maynard points out, the values for
total digestible nutrients must be considered the
most practical measure, both for comparing feeds
and as a basis for feeding standards. It must be
recognized that the values for individual feeds
are not constant and that they do not take account