Formic acid in feed for pigs and poultry

Can formic acid at the MIC be added to the feed enzyme used at 1 % concetration for spraying on to the poultry feed. The enzyme can get contaminated with bacteria becasue of fermentaton and may lead to fouling effect before addition to the feed. I would appreciate the reply. Dr. Farooq Latif

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.

Thanks Dr. Kuckstadt, However, my question persists that in your opinion what sources can be used keeping in mind as you said the enzyme pH which in my case is neutral. Can you suggest agents which can keep MIC so that the enzyme storage could be increased. best regds, Dr. Farooq

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.

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?

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.

Worldover, use of raw (pure acids) is not considered good for feed plants and workers' health. Why companies dealing in organic acids as acidifiers for animal feed/animal gut recommend more use of buffered acids which is far effective than acid salts alone. Dr. RAHUL CHANDRAVANSHI

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!

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.

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