Note: Descriptions are shown in the official language in which they were submitted.
0050/46217 CA 02230175 1998-03-16
Aqueous solutions of formic acid, propionic acid and ammonia and
the use thereof
The present invention relates to aqueous solutions of formic
acid, propionic acid and ammonia and the use thereof in animal
nutrition.
DE 26 53 448 discloses aqueous solutions of ammonia and formic
acid having a molar ratio of formate to ammonium ions of 4:1, and
the use thereof for conserving substrates to prevent microbial
decomposition. The addition of further monocarboxylic acids,
preferably from the group consisting of acetic, propionic,
isobutyric, n-butyric, n-valeric, 2-methylbutyric, levulinic,
sorbic, acrylic and methacrylic acid, is also described there.
However, the solutions described in DE 26 53 448 have a strongly
acidic pH (pH<3) and are therefore not optimally suitable for
some applications in animal nutrition. Increasing the pH, for
example by adding a larger amount of ammonia, does however lead
to the undesirable result that the freezing points of the aqueous
solutions are substantially above 0°C, which makes such a solution
difficult to handle in agricultural practice.
It is an object of the present invention to provide aqueous
solutions which contain formic acid and ammonia and on the one
hand do not have a pH which is too strongly acidic and on the
other hand possess a freezing point which is sufficiently low for
practical purposes.
We have found that this object is achieved and that the desired
properties can be obtained with an aqueous solution consisting of.
a) 35-42~ by weight of propionic acid,
b) 30-40~ by weight of formic acid,
c) 5-10~ by weight of ammonia and
d) 10-30~ by weight of water.
A particularly preferred embodiment is an aqueous solution which
consists of
a) 38~ by weight of propionic acid,
b) 35~ by weight of formic acid,
c) 6-8~ by weight of ammonia and
d) 20$ by weight of water.
0050/4.6217 .
CA 02230175 1998-03-16
2
The novel solutions can be prepared by adding gaseous ammonia or
aqueous ammonia solution to aqueous solutions of the acids so
that the stated weight ratios are reached. Starting from aqueous
solutions of the ammonium salts of one or both acids, it is also
possible to add further free acid until the desired weight ratio
is reached.
The novel solutions are used in animal nutrition, especially as
an additive for feed for pigs, piglets and poultry, such as
l0 chickens and turkeys. They are particularly suitable for
conserving animal feed, preferably liquid feed, to prevent
undesirable microbial decomposition. In addition to the
pH-lowering and antibacterial action, the novel solutions also
have a nutritional effect, which is due in particular to the
formic acid and is displayed especially in pig feeding.
The novel solutions can also be used for conserving and/or for
disinfecting the drinking water used in animal nutrition.
A further use of the novel solution is in the production of silo
feed (ensiling). In silo feed, undesirable microbial
decomposition, especially due to molds and putrefactive bacteria,
frequently takes place in addition to the desired lactic acid
fermentation. In order to prevent this undesirable putrefaction,
the novel solutions may be added to the animal feed.
As a rule, the addition of 0.1 - 10 kg of aqueous solution per
tonne of animal feed is sufficient for successful conservation.
The aqueous solutions are preferably added in amount's of
0.5 - 4.5 kg per tonne of animal feed.
The addition is usually effected directly before ensiling.
The novel solutions have the following properties:
~ They have a pH of from 3.5 to 4.5.
~ Their freezing points are below 0°C, and the
particularly preferred solutions have freezing
points lower than -20°C.
~ Their density is 1.1-1.2 g/ml.
~ The viscosity is 8.82 mPa~s at 20°C.
Examples
The silo materials stated in the following examples were
conserved with a novel aqueous solution (referred to below as
solution A) of the following composition
0050/46217 CA 02230175 1998-03-16
_ 3
38~ by weight of propionic acid
35~ by weight of formic acid
7$ by weight of ammonia
5 20$ by weight of water.
The silo materials thus preserved were each compared with the
corresponding silo materials which, as a control, had been
preserved with formic acid and without a preservative.
In the comparative experiments, the fermentation parameters of
the silo materials were compared.
The silo material used was harvested as finely cut material by
means of a motor-driven silo chopper and was stored in each case
in a 4 m3 experimental silo by the direct cut method.
A total of 9 different silo storages were prepared, starting from
three different silo materials (raygrass, orchard grass and '
alfalfa).
After conservation for more than 5 months, the silo materials
were fed in a series in succession to groups of 6 sheep each,
which were kept in a metabolic cage. Starting from animal feed
taken daily from the silo, a representative sample was prepared
for the 6 days of the experimental period. The stability was
~ determined by a method described in a'1981 INRA publication
"Prevision de la valeur Nutritive des Aliments des Ruminants".
Example 1
Conservation of the raygrass hybrid "Texy", first cycle at
incipient ear-formation stage (harvesting date: May 24, 1995)
Conservation batches Application rate of
Experiment the preservative in
1/t fresh matter
A Control without preservative' -
.
B Control with formic acid 3.53
C Salution A 4.54.
Example 2
~5 Conservation of orchard grass "Amply", first cycle at incipient
ear-formation stage (harvesting date: June 1, 1995).
0050/46217 CA 02230175 1998-03-16
Conservation batches Application rate of
Experiment the preservative in
1/t fresh matter
D Control without preservative-
E Control. with formic acid 3.40
'
F Solution A 4.50
l0
20
30
40
CA 02230175 1998-03-16
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0050/.46217. CA 02230175 1998-03-16
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Example 3
Conservation of alfalfa "Europe", first cycle, bud stage
(harvesting date: June $, 1995).
Conservation batches Application rate of the
Experiment preservative in 1/t
fresh matter
Control without
G -
preservative
H Control with formic acid 4.?1
I Solution A 5.06
The results of the experiments A to I carried out in Examples 1
to 3 are shown in Tables 1 to 3.
Table 1: Chemical composition of the harvested and conserved
green animal feed
Animal feed typeExperi-~DM Content of soluble
ment carboh
drates in
Harvest Ash y
~DM
Raygrass hybrid A 20.1 8.5 22.9
"Texy"
B 21.3 8.5 22.6
C 19.7 8.5 22.6
Orchard grass D 19.4 9.4 8.9
..ply..
E 19.7 9.2 8.3
F 19.4 9.4 8.9
Alfalfa "Europe"G 16.0 10.8 5.6
H 17.2 10.8 4.9
. I 16.0 10.8 5.6
Table 1 shows the chemical composition of the harvested animal
feed for conservation in the silo.
The content of soluble carbohydrates in the raygrass hybrid and
'10 the orchard grass was unusually high. The content in the dry
matter (g DM) was also high. Both show that the chemical
composition of the raygrass and of the orchard grass were very
advantageous for silo storage. The chemical composition in the
case of the alfalfa was normal.
0050/46217 CA 02230175 1998-03-16
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Table 3: Fermentation parameters of the animal feed - alcohols -
Animal feed typeExperi- Total MeOH EtOH PrOFi BuOH
ment alcohols
g/kg DM
Raygrass hybrid A 63.8 0.52 35.94 27.34 0.0
"Texy"
B 18.9 0.50 14.97 3.47 0.0
C 31.8 0.30 22.50 9.03 0.0
prchard grass D 12.6 0.36 10.03 2.20 0.0
~~~pll'~~ E 18.9 0.62 14.08 4.15 0.0
F 13.3 0.29 12.18 0.86 0.0
Alfalfa "Europe"G 42.0 8.52 13.06 19.57 0.89
H ~ 13.0 .4.25 6.64 2.11 0.0
I 19.8 6.61 8.06 5.15 0.0
It is clearly evident from Tables 2 and 3 that, without
conservation (Experiments A, D and G), the fermentation
parameters of the silo material are disadvantageous with the
exception of the orchard grass (D). Without conservation, the
fermentation parameters indicate a high acetic acid and alcohol
content. This indicates disadvantageous heterofermentation. The
raygrass and alfalfa silo material without a preservative had
Poor stability.
The experiments show that the fermentation parameters with the
use of the novel agent are just as good as with the known formic
acid-containing agent.
Moreover, in contrast to formic acid, the novel agent is
noncorrosive and does not irritate the skin in the rabbit test.
This is a substantial advantage with regard to application.
Furthermore, the corrosiveness towards metals is substantially
lower in the case of the novel agent than in the case of the
known agents which contain formic acid as a preservative.
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