Replacement of Acid Components in Pig Diets

For nutritionists, there is sometimes when they are very stressed because the space in the feed is somehow limited: it always has to add up to 100%. They would like to have 110% because they want to add more vitamins, more premix, etc. There's always a question: is there a way to make room in swine diet formulation?

Yes. With the right tools, swine producers can make space in the diet and reduce the amount of acids in the formulation while maintaining performance.

Feed matters

Swine producers look to achieve high levels of productivity, reach full genetic potential and generally have good performance. To do so, we have to look into the feed formulation. We have to look into the components going into the feed which play an essential role. This is where most of the money is invested—feed is actually one of the biggest costs in animal production.

Contaminants in feed can include pathogens. Gram-negative bacteria such as Salmonella and E. coli inflict real economic losses on animal production, so any way to limit their spread is welcome.

Why acidify

  • Help to create a barrier against pathogens
  • Ensure good feed and water quality
  • Address Gram-negative bacterial challenges
  • Help animals maintain normal pH levels in the stomach to support enzyme secretion and digestion

Lowering stomach pH and reducing the buffer capacity of the feed go hand in hand in terms of the acidification feed and its effects in animals.

Over the course of three weeks after a piglet is born, it starts to adapt its stomach pH down to a normal pH level of 3— where optimum activation of pepsinogen into pepsin happens. This is the point where we wean the piglets, changing from a milk diet to a solid diet, sending the stomach pH up to 4 or 5. At these levels, the pepsinogen is poorly activated—and proteins will therefore travel undigested into the intestinal tract and later cause problems.
Application of organic acids can serve to avoid this issue.

The untold story

Aside from reducing pH levels, organic acids have the ability to enter and disrupt Gram-negative bacteria through both undisssociated and dissociated ways—the former having a direct effect: the latter; and indirect one.

The combination of different acids can have a synergistic effect. A trial conducted by BIOMIN showed that the combination of formic acid and propionic acid had a bigger effect on Salmonella and E. coli inhibition than either of the acids administered individually. In this case, one component’s main role is to cross the bacterial membranes while the other lowers the pH—resulting in higher efficacy.

Scientific literature has documented the capacity of certain substances to permeabilize, or make porous, the lipopolysaccharide outer cell wall of Gram-negative bacteria. In this way, organic acids or naturally occurring antimicrobial substances within the animal can more easily enter the bacteria and disrupt the pathogens.

Even at low inclusion levels, the BIOMIN Permeabilizing Complex –a component of Biotronic® Top line– has been shown to be quite effective in permeating the membranes of Gram-negative bacteria.

More room in formulation

Through the combination of organic acids, phytochemical substances and the BIOMIN Permeabilizing Complex comprising Biotronic® Top line, producers can replace a significant portion of conventional acids in the diets while reducing the overall portion of acids applied. A general recommendation would be 1kg of Biotronic® Top line to replace 2kg of conventional acids.

Field experience

The first trial had 12 pens of 10 weaned piglets each, divided into 4 groups: a negative control group (no acids), a benzoic acid-based product group (5kg/ton), Biotronic® Top line (2kg/ton), a combined benzoic acid and Biotronic® Top line group (replacement). Benzoic acid plays a good role in the feed conversion ratio. The replacement group’s results were better than for the negative control or the single acid group.

The second trial was conducted on behalf of a feed mill that wanted to reduce its acids component without any major changes in terms of performance. We replaced 6kg/ton formic acid-based product with 1.5kg/ton of Biotronic® Top line, resulting in slightly better (though not statistically significant) performance, including a 3-point FCR improvement while reducing the total cost of the feed.


  • The combination of organic acids, phytogenic substances and the BIOMIN Permeabilizing Complex have a greater effect than conventional acids.
  • Breaking up the membrane of Gram-negative bacteria boosts the efficacy of antimicrobial substances.
  • Making space in diets eases the job of nutritionists and can generate costs savings.