Water Acidification

Wednesday, January 21, 2026

The use of water acidification to prevent diarrhea in piglets

By Dr. Alfredo Ordonez, Trouw Nutrition

Water, depending on its physical, chemical, and bacteriological characteristics, can be an ally or a threat. Water participates in an extensive variety of physiological processes, such as body temperature regulation, digestion, nutrient transportation, toxin elimination, and pH balance. To participate in such processes, water is consumed in high amounts (ratio of 3:1, according to feed intake). With such a high water intake, a lack of bacteriological quality can lead to the ingestion of large amounts of pathogens, leading to digestive disorders.

In animal production, the bacteriological quality of water can be influenced by factors such as water origin and the cleaning and disinfection of the water lines. Also, low flow rates and relatively high room temperatures at the beginning of the nursery period can promote bacterial growth. Bacterial contamination can be particularly important if diarrhea was a problem in previous batches. The interaction of these factors can modify water quality from one batch to another. Therefore, some strategies, such as regular water analysis, routine line cleaning and disinfection, as well as the use of products that inhibit bacterial growth, such as chlorine and water acidifiers, can improve the bacteriological quality of water.

Enteric origin bacteria, such as E. coli and Salmonella, are pathogens that frequently pollute water via wells, ponds, or water lines. These bacteria do not grow at a pH of 4.0 and lower. Piglets younger than five weeks old are more susceptible to bacterial infection since their stomach is not mature enough to produce sufficient hydrochloric acid to drop the pH of the stomach lower than 4.

To prevent and control intestinal bacterial infections, the swine industry uses zinc oxide (ZnO) and antibiotics. However, these two options are highly questioned by consumers and public health due to their impact on water pollution and the development of antibiotic resistance. Different strategies have been implemented to compensate for the reduction of ZnO and antibiotics utilisation. One strategy is the use of acids to reduce the water pH. Beyond the effect of acids on bacterial growth and survival, it is a sustainable option since they do not pollute, they are not toxic, and they do not induce bacterial resistance.

Some published studies have found that, in some cases, a mix of organic and inorganic acids can also select for ‘beneficial’ bacteria and reduce the pathogenic bacteria. This can be explained by the fact that ‘beneficial’ bacteria, such as Lactobacillus, can grow at a pH lower than 4.0, which is too low for pathogenic enteric bacteria.

Other research has shown the addition of organic acids to water can go one step further and also improve piglet performance. In one Quebec nursery trial, piglets that were given water treated with a blend of free and buffered organic acids (Selko ProHydro Plus) for the first three weeks of the nursery period had seven per cent higher average daily gain, and four per cent better feed conversion, in addition to increased feed intake and body weight.

The combination of organic acids plus chlorine has a synergetic bactericidal effect. To get the maximum profit from water treatment, it is important to use a good acid and chlorine injection system. The pH measurement is also very important, since E. coli can grow once the pH reaches 4.2. This is why in the field, a pH of 3.8 is regularly recommended. Do not forget to regularly test the chlorine concentration and the pH, to avoid bad surprises!

Remember that water acidification is not a silver bullet. It is just one tool for diarrhea prevention and control. A good prevention and control program should address three levels:

• The piglet. Are the weaning conditions in line with the piglet age or piglet maturity (e.g., room temperature, feeding strategy)? Are your piglets well protected? You could discuss the use of a vaccination strategy (sow and/or piglet oriented) with your veterinarian.
• The environment. Are water, feed, ventilation and temperature correct (quantity, quality) upon the arrival of the piglets? Have cleaning and disinfection been perfectly done for pens, water lines, feeders, walkways, boots, overalls, and all other materials entering into contact with piglets?
• The pathogens. Have you worked with your veterinarian to identify the main causes of diarrhea on your farm? Even though they may seem similar, the prevention and treatment of diarrhea can differ if they are caused by bacteria, virus or parasites.

In conclusion, water acidification is an efficient tool to improve water quality and prevent some digestive disorders, if implemented along with other approaches. Please involve your veterinarian and your technical staff to develop a comprehensive strategy to control diarrhea. BP