Heat stress: the effect on water and animal

The weather is getting warmer. Your animals drink more, eat less, and perform worse. You will see this in your production figures, but also in your drinking water system. As water intake rises, microbiological contamination in pipes and water troughs also increases rapidly. As temperatures go up, this process accelerates. Now is the time to act.*

What happens in your pipes

When it is hot, the temperature of the water in your pipes and drinking troughs rises as well. Bacteria grow extremely fast at these higher water temperatures: the population can double every 20 minutes (1,2). This is especially true when pipes are long, water remains stagnant, or drinking troughs are not thoroughly disinfected.

In practice, we see that an increased somatic cell count or a slime layer that quickly returns is often linked to pipes in which biofilm and microbiological contamination have been able to build up undisturbed for years.

The reason: biofilm actively protects itself. The bacteria inside it survive a treatment that would have killed free-floating bacteria long before.

The risks of microbiologically contaminated drinking water

Contaminated drinking water costs money. This is what you stand to lose when microbiological quality is not under control:

• Somatic cell counts in milk: Contaminated water can cause inflammation in your livestock, resulting in higher cell counts and potentially lower milk prices or rejected bulk tank milk. This is especially relevant during the warm summer months, when udder health is already under pressure (3).
• Growth and feed intake: Gut problems caused by bacterially contaminated water reduce feed intake as well as the efficient use of the feed that is consumed, meaning you pay for feed that your livestock cannot use properly (4).
• Time: Managing outbreaks and cleaning the system takes hours that you would rather spend on your business.

By getting this microbiological quality under control before the first real heatwave arrives, you reduce the chance that the coming warm period will affect your farm.

Business case: visibly cleaner water and higher production

Dairy farmer Jan Geerlig from Drenthe recommends the system to everyone after noticing within 14 days that dirt had disappeared, the water looked crystal clear, and production increased by as much as 40 kg per day.

"This summer I saw the effect again in the pasture. Normally, algae appear in the drinking trough within a week, but not anymore. Despite the warm summer with many hours of sunshine, the water remains crystal clear."

Those who invest in cleaner drinking water give cows the best chance to keep drinking enough during warm periods, thereby protecting production, health, and feed intake.

Warmer weather affects every animal differently

Dozens of extra litres per day

Once temperatures reach 20°C, a cow already starts to compensate: she drinks more, eats less, and burns body fat to regulate her body temperature. According to GD Animal Health, water intake can increase by up to 50% during prolonged heat; lactating cows can drink more than 150 litres per day (5).

The consequences for production are immediately visible: during prolonged heat, feed intake can drop by almost half and milk production by even more than half (6,7).

Cleaner water does not start at the trough, but in the system

Many livestock farmers visually check the drinking trough or measure water consumption at a fixed point. That is a start, but not enough. Clean water for your animals requires the entire system to be microbiologically under control. And that is exactly what becomes challenging in warm weather.

Watter provides continuous disinfection of your drinking water system by generating hypochlorous acid (HOCl) on site, ensuring that fresh disinfectant is always available. Our system also means you no longer have to constantly carry jerrycans full of chemicals, and no personal protective equipment is required when using our product.

References:

1. RIVM. (2026). Ziek door dier via voedsel | RIVM. Rivm.nl. https://www.rivm.nl/ziek-door-dier/besmetting/voedsel
2. Wielen, P. W. J. J., van der Dignum, M., Donocik, A., & Prest, E. I. (2023). Influence of Temperature on Growth of Four Different Opportunistic Pathogens in Drinking Water Biofilms. De Bibliotheek van KWR. https://library.kwrwater.nl/publication/70649552/influence-of-temperature-on-growth-of-four-different-opportunistic-pathogens-in-drinking-water-biofilms/
3. FrieslandCampina (2013). Belangrijkste regelingen 2013 voor leden-melkveehouders in Nederland. Melkvee.nl. https://www.melkvee.nl/site/assets/files/0/44/306/44309-1-brochure_regelingen_in_nederland.pdf 
4. Jessica, W., & Jonathan, M. (2026). Water Quality Critical to Broiler Performance | Mississippi State University Extension Service. Msstate.edu. https://extension.msstate.edu/publications/water-quality-critical-broiler-performance
5. GD. (2025). Voorkom hittestress bij rundvee. Gddiergezondheid.nl. https://www.gddiergezondheid.nl/diergezondheid/management/hittestress-rundvee
6. Das, R., Sailo, L., Verma, N., Bharti, P., Saikia, J., Imtiwati, & Kumar, R. (2016). Impact of heat stress on health and performance of dairy animals: A review. Veterinary World, 9(3), 260–268. https://doi.org/10.14202/vetworld.2016.260-268
7. Garner, J. B., Douglas, M., Williams, S., Wales, W. J., Marett, L. C., DiGiacomo, K., Leury, B. J., & Hayes, B. J. (2017). Responses of dairy cows to short-term heat stress in controlled-climate chambers. Animal Production Science, 57(7). https://doi.org/10.1071/an16472