Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
The invention relates to the preservation of high
moisture content grains and silages, the enhancement and
direction of th~ silage or grain fermentation process, and to
compositions useful in such processes.
The use of sulfite containing additives to preserve
food by scavenging oxygen has long been known as described in
various issued patents, e.g., United States Patents Nos.
2,7~9,583 to Harris; 2,825,651 to Loo et al; 3,169,068 to Block;
and 3,284,Z12 to Tribble.
Prior art users of sodium metabisulfite for silage
preservatian purposes, such as is described in the above-noted
Harris patent, have primarily been concerned with the removal
of oxygen to inhibit spoilage based on the growth of oxygen-
dependent mold or bacteria, and on the creation of an
antibacterial substrate.
Karris describes a process for the preservation of
silage by the adaition of an alkaline metabisulfite and urea.
The urea is present to control the corrosivity of the
metabisulfites toward ferrous metals used in the construction of
silos. The proportion of metabisulfite is said, by Harris, not
to be critical and is said to vary from about 0.1 to 10%, by
weight, or from 2 to 200 lbs/ton of silage. In such relatively
high proportions, the metabisulfite has a strong antibacterial
effect on the silage and destroys much of the natural bacteria
required for desired fermentation. On the contrary, as will be
described more fully below, the process and compositions of this
invention produce a rapid anaerobic effect, and then, after
chemical conversion of the alkali metal sulfit~, bisulfite or
metabisulfite to sulfate, serve to direct the fermentation.
In our prior United States Patent No. 3~184,314, we
have also descrihed the preserving and controlling of the
fermentation of high moisture content grain silages by the use
of compositions comprising (a) an alkali or alkaline earth metal
sulfate salt, and (b) an amylolytic enzyme, preferably malt
diastase.
We have now found that we can provide superior, fast
acting preservation of and fermentation control for various
silages and stored grains, especially high moisture content
grains, by the use of the compositions of this invention.
The invention relates to the preservation and
fermentation control (in the sense of directing the course of
the fermentation) of various silages and stored grains,
especially high moisture materials, such as high moisture
content corn.
In order to provide palatable silage and grain free
from tastes or odors which would discourage feeding and still
retain a high proportion of nutrient and vitamin values, it has
been found essential to stop undesired mold and bacterial growth
as quickly as possible, while at the same time directing the
fermentation so that the formation of propionic acid is promoted.
The present composition achieves this dual result in a
uniquely effective way by adding to the silage or grain from
about 0.2 to less than 2 lbs/ton of silage or grain an alkali
metal sulfite, bisulfite, metabisulfite, or mixtures thereof.
If the amount is below about 0.05 lbs/ton, the effect is
inadequate to produce the desired anaerobic effect. If the
amount exceeds 2.0 lbs~ton, a strcng antibacterial effect is
produced in the silage with the destriction of natural bacteria
essential to proper fermentation and so the conditions for
natural fermentation are lost. Sulfite amounts at the lower end
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of the range have been found particularly effective with sulfite
amounts of 0.2 to 1.5 lbs/ton silage preferred and 0.2 to 0.8
lbs/ton silage particularl~ preferred.
While the method of the invention may be practiced
solely using alkali metal sulfite, bisulfite, metabisulfite or
mixtures thereof, the best results are obtained by using
compositions comprising such compounds together with other
additives.
The preferred compositions of the present invention
comprise the following ingredients in the indicated amounts:
Constituent Amount
a) alkali metal or alkaline 0.2 to less than 2 lbs/ton
earth metal sulfite, bi- silage
sulfite or metabisulfite
b) alkali metal or alkaline 05. to 2 lbs/ton of silage
earth metal sulfate
c) amylolytic enzyme, prefer- 0.02 to 5 lbs/ton of silage
ably malt diastase
The compositions may be mixed with silage in any
known manner, as for example, by preparing an aqueous solution
or dispersion of the ingredients and spraying solution or
dry granules on the silage while agitating the silage mass to
effect thorough coverage.
The compositions are particularly effective on high
moisture content corn and other high moisture grains. A high
moisture content corn or grain is generally a corn or grain
containing from about 10 - 35%, by weight, of moisture.
We have discovered that the use of certain effective
amounts of alkali metal sulfite, bisulfite, metabisulfite or
mixtures thereof permit both effective protection of the silages
of corn, grass, hay, and the like, and high moisture content corn
and grains from the effects of the growth of aerobic moldst and
S
also contributes to the desired control of the silage
fermentation. Effective amounts of the alkali metal sulfite,
bisulfite or metabisulfite are from about 0.2 to less than 2
lbs/ton of silage, preferably 0.2 to 1.5 lbs/ton silage, most
preferably 0.2 to 0.8 lbs/ton silage.
The function of the alkali metal sulfite, bisulfite
or metabisulfite, sodium metabisulfite being preferred, is
two-fold. It acts as a precursor of sodium sulfate which acts
to control fermentation by favoring the production of a
preponderance of propionic acid and disfavoring the co-production
of butyric acid, both of which are secondary products of lactic
acid which is the first byproduct of the fermentation cycle.
At the same time, it acts quickly to remove oxygen entrapped
in spaces between feed particles so that a substantially
anaerobic environment is rapidly formed. Th~ anaerobic
environment not only favors the conversion of lactic to
propionic acid but also prevents the growth of aerobic molds
which are undesirable in feed. With the presence of the oxygen
scavenging alkali metal sulfite, bisulfite or metabisulfite, the
oxygen is tied up as a sulfate in an exothermic reaction, and
the desirable fermentation proceeds rapidly without mold, toxins,
or excessive heat formation, and with the production of a
preponderance of desirable fermentation products.
For maximum advantage to be taken of the process, the
alkali metal sulfite, bisulfite or metabisulfite should be
applied to the silage with additional sodium sulfate, and
preferably with an amylolytic enzyme, such as malt diastase, or any of
alpha amylase (3.2.1.1.~, beta amylase (3.2.1.2.), or amylase from
Aspergillus Oryzae. Other additives, such as a surfactant and food grade
acids, formic acid or formalin may also be added to the g.ain
, .
or silage. Any suitable non-toxic sufactant, preferably dimethyl
pol~siloxane to help wetting and spreading of the comDosition
throughout the silage,is satisfactory. Anionic, cationic,
amphoteric, and non-ionic surfactants have all proved useful.
Examples of suitable surfactants which may be used include, bu~
are not limited to, sodium alkylsulfonethanolamine, dimethyl-
polysiloxane ammonium alkylarylpolyethersulfonaLe, sodium
alkylarylpolyethersulfonate, sulfonated fatty acids and lignin
sulfonate and its salts.
In achieving fermantation control in silages and high
moisture grains, an important advantage of the invention is that
it avoids the usual delay of from about 28-48 hours for silages
and grains to become anaerobic. In this delay period, some
molds may grow and undesirable fermentation may proceed. With
the present method and compositions, however, an anaerobic state
is rapidly reached and a higher proportion of the plant material
is convered to desirable silage.
EXAMPLE I
Under controlled conditions, a first batch of 67%
moisture corn silage was mixed at 70F with a mixture of 96%
sodium sulfate and 3~ malt diastase. The mixture was added in
an amount of about 1-1/2 lbs/ton of corn silage.
A second batch of silage was treated in the same
fashion as the first, but 0.3 lbs of soidum sulfite per ton of
silage was also added, and replaced 0.3 lbs of sodium sulfate.
The production of lactic acid and propionic acid and
the presence of mold were monitored after 48 hours in each batch.
The results were as follows:
7 ~ 7
Lactic Acid Propionic Acid Mold Count
:
Batch #1 0.3% 0.05% 180,000JGm
(70,000/Gm-
96 hours)
Batch #2 1.1% 0.3% 1,600/Gm
(40/Gm-96
hours)
EXAMPLE II
:
Batches of 30% high moisture corn were treated in the
same manner as was the corn silage in Example I. Mold was
monitored at the end of S days and at the end of 30 days.
Chemical anaylses were made at the end of 30 days. Batch #3
contained no sulfite while Batch #4 contained the soldium sulfite.
Acetic Butyric PropionicMold Mold
Acid Acid Acid (30 days) (5 days)
Batch #3 0.4% 0.1~ 0.1S~ +l */ +l */
Batch #4 0.2% 0.01% 0.4% **/ 0 **/ +- ***/
:' .
*/ +1 =- 10,00 to 25,000 mold spores
**/ 0 = no mold
***/ +- = less than 10,000 mold spores
With use of the compositions of the present invention
there was no mold present at the end of 30 days of ensiling, and
very little mold at the end of 5 days under the conditions of
this experiment.
Oxygen was not present in Batch #4 at the end of a
24 hour period, whereas it was present in Batch #3 after 24 hours
of fermentation.
Fresh untreated silage ordinarily exhibits a mold
count of 50,000/gm which rises to 250,000 in 4 hours and remains
at that level after 96 hours. With the compositions of the
present invention, a rapid reduction in mold count is realized
8 ~ '7
after between 48 and 96 hours. This indicates that little, if
any, mold toxin will be pxoduced when following the teachings
of this invention.
The much higher levels of lactic and propionic acids
indicate superior progress of the fermentation process in the
direction desired to produce more palatable and nutritious silage.
In general, the compositions of the invention
comprising 10 to 97% of any of the inorganic sulfates, such as
sodium sulfate, potassium sulfate, magnesium or ammonium sulfate,
0.3 to 3~ amylolytic enzyme and 2 to 20% alkali metal sulfite,
bisulfite and metabisulfite should be used on silage at a rate
of about 0.3 to 5 lbs/ton, thus maintaining the effective amount
of the sulfite per ton of silage in the ranges discussed above.
While former experimenters used sodium sulfite or
metabisulfite by itself, they used too high a concentration in
an effort to kill all the organisms in silage and thereby tended
to kill much or all of the lactic acid and propionic acid
producing bacteria, as well as the yeasts and molds. This left
the silage in a state harder to digest and with no biosynthesis
from fermentation and no preparation of the cells and cell
cementum to become absorptive and save the all-important silage
j~ices with their proteins and vitamins.
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