AU706907B2 - Aqueous solutions of formic acid, propionic acid and ammonia and the use thereof - Google Patents

Abstract

The invention concerns an aqueous solution consisting of: a) 35-42 % by wt. of propionic acid, b) 30-40 % by wt. of formic acid, c) 5-10 % by wt. of ammonia and d) 10-30 % by wt. of water and its use in animal nutrition.

Description

0050/46217 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 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.

0050/46217 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 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 amounts 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 Their freezing points are below 0oC, and the particularly preferred solutions have freezing points lower than -20 0

C.

Their density is 1.1-1.2 g/ml.

The viscosity is 8.82 mPa-s at 20 0

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

RA

NT o>< 0050/46217 3 38% by weight of propionic acid by weight of formic acid 7% by weight of ammonia 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 m 3 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 "Pr6vision 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 l/t fresh matter A Control without preservative 40 B Control with formic acid 3.53 C Solution A 4.54 Example 2 Conservation of orchard grass "Amply", first cycle at incipient ear-formation stage (harvesting date: June 1, 1995).

0050/46217 4 Conservation batches Application rate of Experiment the preservative in 1 fresh matter D Control without preservative E Control with formic acid 3.40 F Solution A 4.50

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Table 2: Fermentation parameters of the animal feed Animal feed Experi- %DM pH Total N N-NH 3 soluble Acids (g/kg DM) Total type ment g/kg DM N alcohols LA AA PA BA VA g/kg DM Raygrass A 21.8 3.71 15.7 8.2 66.4 129.2 82.4 0.8 0.0 0.0 63.8 hybrid "Texy" B 21.3 3.78 16.5 6.6 60.4 58.7 40.8 0.4 0.0 0.0 18.9 C 20.5 3.81 16.8 4.5 64.1 96.6 42.6 2.6 0.0 0.0 31.8 Orchard grass D 20.7 3.87 19.1 7.5 60.2 104.1 25.4 1.2 0.2 0.0 12.6 "Amply" E 20.6 3.85 18.6 7.8 63.7 105.1 28.7 1.0 0.6 0.0 18.9 F 20.7 3.88 19.8 5.4 59.8 100.9 21.8 9.0 0.1 0.0 13.3 Alfalfa G 19.8 4.72 32.5 13.0 73.2 50.2 97.3 7.0 0.0 0.0 42.0 "Europe" H 21.2 3.99 32.3 7.5 61.5 86.3 32.7 0.8 0.0 0.0 13.0 I 19.4 4.16 34.1 9.6 68.9 117.2 36.0 12 0.0 0.0 19.8 UM ary matter, N nitrogen, N-NH 3 bound nitrogen, soluble N soluble nitrogen, LA lactic acid AA acetic acid, PA propionic acid, BA butyric acid, VA valeric acid 0050/46217 6 Example 3 Conservation of alfalfa "Europe", first cycle, bud stage (harvesting date: June 8, 1995).

Conservation batches Application rate of the Experiment preservative in l/t fresh matter G Control without preservative H Control with formic acid 4.71 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 green animal feed harvested and conserved Animal feed type Experi- %DM Content of soluble ment carbohydrates in Harvest Ash

%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 "Amply" 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 the orchard grass was unusually high. The content in the dry matter 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.

RA4,, -zT N~~7~i 0050/46217 7 Table 3: Fermentation parameters of the animal feed alcohols Animal feed type Experi- Total ment alcohols MeOH EtOH PrOH BuOH ment alcohols Sg/kg DM Raygrass hybrid A 63.8 0.52 35.94 27.34 0.0 "Texy" "Texy" B 18.9 0.50 14.97 3.47 0.0 C 31.8 0.30 22.50 9.03 0.0 Orchard grass D 12.6 0.36 10.03 2.20 0.0 "Amply" "Amply" 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 conservation (Experiments A, D and the that, without fermentation parameters of the silo material are disadvantageous with the exception of the orchard grass 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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Claims (6)

1. 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.

2. Use of an aqueous solution as claimed in claim 1 in animal nutrition.

3. Use as claimed in claim 2, wherein aqueous solutions as claimed in claim 1 are used for conserving animal feed.

4. Use as claimed in claim 2, wherein aqueous solutions as claimed in claim 1 are used for conserving or disinfecting drinking water. A composition for conserving animal feed, which essentially consists of a) 35-42% by weight 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.

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6. The aqueous solution as claimed in claim 1 substantially as hereinbefore described with reference to solution A. DATED this 22nd day of April, 1999 BASF AKTIENGESELLSCHAFT WATERMARK PATENT TRADEMARK ATTORNEYS 290 BURWOOD ROAD HAWTHORN VICTORIA 3122 AUSTRALIA LCG/JGC/MEH DOC 26 AU7126996.WPC AJ N