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Formic acid in feed for pigs and poultry

Microbial inhibition secures performance benefits

Published: May 27, 2011
By: Sarah Mellor & Christian Lückstädt (Addcon)
Formic acid - strongest bactericidal/ bacteriostatic effect
The performance benefits of including formic acid in feed for pigs and poultry that have been reported widely under farm conditions stem from its strong antimicrobial activity; as seen in numerous in vitro tests.
Contaminated feedstuffs, recontamination during storage, transport and outfeed result in significant losses in productivity, if not severe outbreaks of disease, as a result of pathogen growth. Feed is an excellent source of nutrients for animals and pathogens alike and the intestinal environment provides excellent growth conditions for bacteria, so adding bactericidal or bacteriostatic agents prevent disease and allow livestock to utilise feed efficiently. Mould growth also reduces the nutritive value of feed and can result in mycotoxin contamination, which can cause disease and mortality and render livestock more susceptible to bacterial diseases. Bacterial contamination in drinking lines and drinkers should also be prevented.
One way in which feed additives can be compared is in their ability to combat bacterial growth. The minimal inhibitory concentration (MIC) has long been a useful tool in establishing how effective an agent is at inhibiting growth of microoorganisms. The lower the MIC for a particular agent and microbe, the less is needed and the more effective it can be considered.
Formic acid has been shown effective against a number of pathogens under practical conditions, in tests with both poultry and pigs as well as other livestock species. Organic acids exert their bactericidal and bacteriostatic activity within the cell of the target organism, where the hydrogen ions disrupt the ionic balance, forcing the cell to expend energy in actively expelling the ions. However, not all acids are equally effective. Inorganic acids might be considered extremely effective in decreasing pathogen load in the stomach of piglets, indirectly through pH reduction (since they do not have direct antimicrobial properties); but their use in feed is limited by their tendency to cause irritation during handling, feed refusal by animals and corrosion of equipment used in transport, at the feed mill and on the farm.
The strongest bactericidal and bacteriostatic effects have been reported for formic acid, which is effective against the most serious bacterial threats to poultry and pig productivity, as shown in Table 1. The MIC for formic acid against these pathogens lies in the range of 0.1 to 0.2 percent, i.e. the lowest dose of the acid at which bacterial growth is prevented.
Table 2 compares the effect of formic acid against that of two other widely used organic acids - propionic and lactic acids. The MIC of formic acid to inhibit growth of all pathogens tested is noticeably lower than the other two acids. Between 0.05 and 0.25 % less formic acid solution is needed than each of the other two acids for a given pathogen. Given the intense pressure on feed manufacturers to mobilise every fraction of a percent of feed available to maximise productivity, this comes as good news to all those who strive to produce high quality, safe feed.
In practice, formic acid salts, with their improved handling characteristics and better palatability to livestock, have been found to be a more user-friendly method of applying formic acid to feed and water, without compromising their efficacy.
Table 1: Antimicrobial effect of formic acid against different bacterial (after Strauss and Hayler, 2001) - Minimal Inhibition Concentration MIC in % 
Microbial inhibition secures performance benefits - Image 1
Figure 1: Antimicrobial effect of formic, propionic and lactic acid against different bacteria (Strauss and Hayler, 2001).
Microbial inhibition secures performance benefits - Image 2
Microbial inhibition secures performance benefits - Image 3
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Authors:
Christian Lückstädt
ADDCON
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Christian Lückstädt
ADDCON
5 de marzo de 2018
Yes, you can - but as outlined before the use of pure formic acid may cause some negative side-effects due to its volatile, corrosive and dangerous nature. We advice therefore to use formic acid containing salts, like sodium diformate. This crystalline molecule can reach, due to its double-bond structure, deep into the GI-tract of a bird. Sodium diformate has been widely used the world over in layers - in order to improve the health status of the bird, as well as the production parameters. Gut health is improved due to the suppression of potentially harmful bacteria (e.g. E.coli, Salmonella), which may lead to reduced mortality rates, while the know impact of the acid-salt on mineral digestion (especially of calcium) leads to a better egg shell formation. In the end, those impacts will be responsible for the manyfold noted improved hen-day percentage.
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Christian Lückstädt
ADDCON
30 de agosto de 2011
Dear Dr. Chandravanshi, I completely agree with you. Pure organic acids are volatile, corrosive and can be hazardous to workers health. The published article should show only the possibility to counteract microbial contamination with organic acids. I am fully aware that buffered acids or acid salts are more widely used in the industry so far. However, please consider the effect of organic acid double salts - like potassium diformate (for use in swine and aquaculture) and sodium diformate (for use in poultry). Diformates combine the strength of free formic acid with the safety and stability issues of org salts - diformates are heat stable, non-corrosive, non-hazardous...while liberating the effect of the free acids only into the GIT of the animal. Thus, those additives are very safe, yet very effective!
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Christian Lückstädt
ADDCON
11 de agosto de 2011
According to the study, which is published at Feed Magazine/Kraftfutter 4 in 2001 the acids were added to a medium at a similar pH, but due to the acid strength pH shifted differently - pH in the formic acid treatment fall deepest, while the propionic and lactic acid treatment had a similar pH-reduction. This means that on one hand the MIC can be partly explained via a pH effect, while the authors speculated for lactic acid and its higher MIC that tjhis may be due to its role as an intermediate/final product in energy metabolism. As a general comment I would say the MIC will differ under different surrounding pH-levels, but not all effects can be explained with pH alone. Several other factors as pKa, metabolism, chemical structure etc. will be involved. However, MIC is a useful tool/step in having a first judge on effect of acids as anti-bacterial or anti-mould agent.
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Mathieu Cortyl
Tonisity
11 de agosto de 2011
This is a very clear and interesting article, however I believe it misses one point: antimicrobial activity (and therefore MIC) of an organic acid is also depending on the pH of the environment. The higher the pH, the more easily the acid will dissociate (as it “tries” to reduce the pH) and as a consequence, its antimicrobial efficacy will be reduced. Is it possible to know at what pH the study of Strauss and Hayler was performed? Could the ranking of the acids in terms of efficacy change when conditions such as pH change?
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Christian Lückstädt
ADDCON
11 de agosto de 2011
You spoke about "contamination" of your liquid (sprayable) feed enzyme...this may be due to bacteria, mould and yeast I suppose. As said earlier a pure acid, like formic acid would be in my opinion contra-productive. However, there are agents available, called neutral acid salts - like a patented combination of buffered propionic acid and Na-benzoate which may be useful for your purpose, since they can inhibit the growth of aforementioned bacteria, mould and yeast. But since I do not know the whole process it is tricky to advise. You may contact me under christian.lueckstaedt@addcon.com for further evaluation of the topic.
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Christian Lückstädt
ADDCON
11 de agosto de 2011
Dear Dr. Latif, Enzymes have a certain pH-optima which is usually (with a few exceptions like pepsin) in the range from slightly acidic to neutral/slightly alkaline. A direct mixing of pure formic acid, which has a pH well below 2 and a feed enzyme is therefore not recommended. However, the use of in-feed acidifier, also based on formic acid (for instance Formi NDF based on sodium diformate) and enzymes, like phytase, in combination in finished feed is highly recommended. You can expect synergistic effects between the two.
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Mr.Pampana
28 de mayo de 2019

Which salt of organic acid is best suited in shrimp culture for controlling WFS?

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Gaber Abdel Hamid Abdel Rahman
28 de noviembre de 2018

What can I use for silag from organic acid (formic or propionic or lactic or what?) , and in any concentrations? And how can I apply it onto silag? Thanks in advance.

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EPAFRODITO NOLLORA
7 de marzo de 2018
Yes, thank you of the information supplied to us producer of eggs, however,what i can additionally put in as to productivity of a hen as good eggs producer could have said ingredient be mixing into morenga leaves duly dried and powder for 3 days then the hen have energy to produce much production quality of eggs, this experience of my poultry farm have been practice but there is no scientific approval yet to be reckoning from other country but Philippines..ATTY.EPAFRODITO NOLLORA - Animalhusbandray technician
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Willie
1 de marzo de 2018

Can I use Formic Acid in the feed in laying Chicken that are in production?

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