Frequently Asked Questions

Frequently Asked Questions (FAQ) is a new returning item in 'The Difference'. For this issue we asked our sales managers for questions they receive often and selected the two from them. Feel free to contact us if you have such a question that you like to have addressed!
This issues questions are:
- Can a mold inhibitor sanitize the feed/raw material?
- What is the difference between glycerol esters of butyric acid and coated salts of butyric acid?

Can a mold inhibitor sanitize the feed/raw material?
A normal dosage and treatment with a mold inhibitor doesn’t sterilize the feed, it just decreases the number of viable mold and yeast and controls the microbial process during storage. The higher the dosage, the stronger the inhibition of the microbes.  Therefore it is important to not under dose the product and to follow the recommended storage period.

A mold inhibitor is a product designed to inhibit mold and yeast growth. Due to its strong and broad effect on yeast and mold propionic acid is normally the base of the product. It works by several different and distinct ways on the microbial cell. Propionic acid lowers the intracellular pH inhibiting growth and kills by that the cells.  Propionic acid and propionate also accumulate in the microbial cell and block metabolism by inhibiting enzymes. In addition Propionic acid is lipophilic and soluble in the cell membrane, where it acts as proton ionophore (H+ channels). It facilitates the H+ transport into the cells, forcing the microorganisms to use more energy pumping out protons to maintain their usual internal pH.

To reach high effect of a mold inhibitor it needs to be mixed in to the feed, the more homogenous the mix, the better effect. For liquid mold inhibitors this is normally handled by spraying the product with special nozzles in a screw conveyor so that the feed can knead against each other during transportation and ensure the product is evenly distributed.


What is the difference between glycerol esters of butyric acid and coated salts of butyric acid?
This question can be answered by looking at the following areas: chemically, physically, functionally and application.

Chemically: ProPhorce™ SR has a strong ester bond between glycerol and the butyric acid which is pH stable and only hydrolyses under influence of lipase which isfound in the small intestine. Salts of butyric acid have a weak ionic bond between the Ca or Na and the butyric acid which means they hydrolyse easily

Physically: ProPhorce™ SR is stable at high temperatures and is available in liquid and dry form. Furthermore it has no odour issues. Coated salts are not temperature stable as at 50 degrees C the fat coating starts melting. They are only available in dry form and still have odour issues when processed at higher temperatures.

Functionally: ProPhorse™ SR has a dual action, it already is antibacterial in the feed and also releases butyric acid in the small intestine. Coated salts release their butyric acid in the small intestine and have no antibacterial action in the feed.

Application: ProPhorce™ SR has a high content of butyric acid compared to coated butyric acid due to the high proportion of the coating material. ProPhorce™ SR can be dosed either as a liquid and drinking water application but is also available in the dry form. Coated salts are by their very nature only available in the dry form.

Butyric acid form




 Butyric acid

 Pure liquid 



 Sodium or calcium butyrate 

 Free salts of butyric acid - dry 



 Coated sodium or calcium butyrate 

 Pearls of salts of butyric acid - dry 



 Butyrins (ProPhorce™ SR)

 Glycerol esters of butyric acid - liquid or dry 




Hugo Hjelm

Technical Support Manager

+46 435 380 55

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