Could Poor Water Quality Be Costing You Milk, Fertility and Profit?

A case study from Dundraw Farm shows how something as simple as cleaner water can have a major impact on milk yield, fertility and herd health.

Water is often described as the most important nutrient in a dairy cow’s diet, yet it is frequently overlooked. While feed, housing and health plans receive close attention, hidden problems within drinking systems can quietly undermine herd performance.

That was the experience at Dundraw Farm, where recurring E. coli mastitis cases and ongoing concerns over bacterial contamination prompted a closer investigation into the farm’s water supply.

Hidden problems below the surface

Despite regular cleaning of water troughs, testing revealed that contamination wasn’t just a surface issue. Bacterial build-up and biofilm within the pipework and drinking system were creating an environment in which harmful bacteria could thrive.

Although the water appeared clean, the underlying bacterial load was placing continual pressure on cow health and productivity. Importantly, the most representative sample wasn’t taken from the source, but from the point where cows actually drink.

Tackling the issue

Working with water hygiene specialists Intermax, the farm implemented a Huwa-San water treatment programme designed to improve hygiene throughout the entire drinking system.

The approach included:

• Comprehensive water testing and system assessment
• Automated Huwa-San dosing
• Continuous treatment of the water supply
• Remote monitoring and ongoing support

By targeting bacteria and biofilm throughout the system, the quality of water consumed by the herd improved significantly.

Measurable improvements

Following the changes, Dundraw Farm reported several key benefits:

Increased water intake

Daily water consumption rose by around 10%, helping support higher milk production and overall performance.

Higher milk yields

High-producing cows recorded an average increase of 1.3 litres of milk per day, highlighting the direct link between water quality and productivity.

Improved herd health

The farm also saw:

• Reduced bacterial counts
• Lower somatic cell counts
• Reduced immune system stress
• Improved fertility performance
• Increased butterfat levels

Michael Duncan, owner of Quest Nutrition, who monitored the results, said removing the bacterial challenge allowed cows to direct more energy towards production, fertility and health rather than continually responding to environmental stress.

When did you last test your water?

Many producers focus heavily on nutrition and feed quality, but water quality can have an equally significant impact on performance.

Even where troughs are cleaned regularly, bacterial contamination and biofilm can persist throughout the drinking system, creating hidden challenges that affect health and productivity.

The experience at Dundraw Farm demonstrates that improving water quality can deliver tangible benefits, including increased water intake, higher milk yields and improved fertility.

So, if your herd isn’t performing as expected and the cause isn’t immediately obvious, perhaps there’s one simple question worth asking: When was the last time you tested your water?