Health and performance of the pigs is what drives profits in pig production. Therefore farmers want to build the most modern animal houses, to have a quality feed and to select pigs with the best genetics. But sometimes they tend to forget that drinking water is the most important nutrient for farm animals and that the animals drink three times as much as they eat solid feed.
Acidifying the drinking water can be the solution to improve the quality of the ‘forgotten nutrient’. Increasing the quality of the drinking water can result in improved performances of the animals, in less bacterial load in the water or in less formation of ‘biofilm’ (an organic layer of ‘slime’ in the pipes, in which bacteria and fungi grow). This article describes the advantages of drinking water acidification with organic acids.
The pH effect of organic acids
Compared to feed, which usually has a higher buffer capacity (due to protein sources and minerals), water has a very small buffering effect. The only parameter which can have an effect is the hardness of water. When applying single acids in drinking water, the pH decreases very quickly and if the dosage is too high, the pH can lower too much, what leads to negative results (less water intake, decreased performances). Therefore a mix of organic acids is favorable to acidify the drinking water because these organic acids have a buffering effect that makes the pH decreases slowly.
If the water is acidified, the pH in the digestive tract of the pigs will be lowered. This has a positive effect especially in the stomach and the small intestines. Due to the lower pH the growth of pathogenic bacteria (e.g. E. coli, Salmonella and Campylobacter) is inhibited and the growth of beneficial bacteria (e.g. lactic acid bacteria) is stimulated.
The bactericidal effect of organic acids
Organic acids have their own pKa-value. The pKa value equals to the pH value at which 50% of the organic acid is dissociated and 50% undissociated. If the pH is lower than the pKa value, then the undissociated form will be dominant (= the desired effect). The right combination of acids with different pKa values results in a synergistic product that always provides undissociated molecules, even at a higher pH.
The undissociated form of the organic acids is able to penetrate the cell wall of the pathogenic bacteria. Inside the cell, the organic acids will dissociate and disturb the electron balance of the cell, what leads to the death of the cell.
The observed effects of organic acids
Acidifying the drinking water prevents weaning diarrhea in piglets. In adult pigs, the acid secretion occurs automatically in the stomach by special cells in the stomach wall. When the piglets are fed with sow milk, there is sufficient acidification in the stomach because sow milk is a good substrate for lactic acid bacteria. At the moment of weaning, the acid secretion of piglets is insufficient, and the produced acid is bind by buffering particles like soy or lime in the feed. This makes the piglets very sensitive for weaning diarrhea. Acidified drinking water supports the piglets in this critical period after weaning.
Organic acids have a positive influence on the digestive tract of the pigs. They increase the digestibility of ileal proteins and amino acids and they stimulate a whole range of metabolic enzymes. Also a higher absorption of Ca, Fe, Mg and Zn is notified.
Due to these effects, acidifying drinking water with a blend of organic acids gives the highest return based on lower feed costs, better feed conversion rate, a higher growth rate and lower mortality. This makes organic acids the best alternative for active growth promoters.
