The Vermont watchman. [volume] (Montpelier, Vt.) 1883-1911, 1894-01-17
Rational Cattle Feeding.--NO. 3,

FEEDING BY THE CHEMICAL METHOD
OF EQUIVALENT RATIONs.
While practical men were seeking to
learn the nutritive value of feeding
stuffs by experiments upon their ami
mails, the chemists, not having the
same facilities for practical tests, at
tempted to solve the problem in another
way, by studying the feeding stuffs
themselves.
The food consumed by an animal
consists of two portions ;-one insoluble,
indigestible and useless, which is re-
jected as dung after passing through
the body; the other, soluble, digestible,
and capable of being taken into the
system. Starting from the true prin.
ciple that these soluble, digestible por-
tons are really the only nutritive parts
of the food, the earlier agricultural
chemists believed that they might be
able to measure the nutritive strength
of different feeds by the relative pro-
portion of their soluble matter, deduc-
on being made for the moisture al
ways contained in even the driest hay
1t was thus that Davy in England,
and Springel in Germany, undertook
the summary analysis of the most COM
mon feeds, and made known the rela-
tive proportions of their soluble and
nutritive parts. But these nutritive
equivalents of solubility being often
found greatly at odds with practical ex-
perience, it was essential to note care
fully that if the soluble parts only are
nutritive, they are so in very different
degrees; and consequently that there
must be amongst them one or more ele
ments of superior importance,
Mons. Boussingault, noting that the
relative proportions Of saccharine,
starchy and fatty matters are extremely
variable in different kinds of forage,
without being generally in any close re-
lations with their practical feeding
value, while protein, existing in all
plants in much less variable amount,
is usually proportional to their observed
practical value, - thought he might
measure the nutritive value of feeding
stuffs by their richness in protein the
more so, as this vegetable protein has
exactly the same composition as the
protein of animals, which constitutes,
as the organic base of the animal body,
the very substance Of their principal
tissues.
Thanks to the analysis of Messrs.
Boussingault, Payen, Letellier, Girar-
din, etc., we soon had the richness in
nitrogen (the distinctive element of
protein) of nearly all our feeding ma
terials for both animals and men; and
these azotic chemical equivalents were
long in favor in the French schools
But practical men, nevertheless, dis
covered that, though the nutritive
equivalents, thus theoretically worked
out, were sufficiently correct, especially
for working animals, when they COM
pared some natural foods-like hay and
straw, roots and tubers, grains and oil
cakes found that they varied much
from reality, when compared with feeds
of another kind,-or when applied to
animals under other conditions, such
as wool sheep, etc.
From these facts, established by ex-
perience, it was necessary to conclude
that if the protein of the food repre-
sents the flesh, the weight of the living
body which contains it, and even, up
to certain point, the work which it
can supply, it nevertheless cannot by
these alone measure the nutritive
power of the feeding materials; and
that it is necessary also to take into &C
count, along with the protein, the as
similable plastic portion of the feeding
materials, other digestible principles
contributing equally to nutrition, al
though not susceptible of becoming a
part VI lhC DOuJ SuCu as
are called respiratory principles, be-
cause they serve specially to supply the
heat necessary for life, by their trans
formation in the act of respiration.
Thus, in the proportion that we ad-
vance in the study of this question, we
recognize new difficulties, and see the
necessity of determining not only the
nitrogenous matter of the forages, but
also the saccharine, starchy and other
like foods, as well as the fatty matter
that is to say, the necessity of full and
complete analysis of all feeding mate
rials-an immense work, in which a
great number of able chemists have
now labored for upwards of forty years.
In considering the neutrality-suspicious.
material that would be lacking in the
nutritive equivalents, deduced from its