When we talk about livestock nutrition, the conversation usually starts with feed. Protein, energy, dry matter, minerals, pasture quality and supplements are all closely considered. Producers invest considerable time and money getting these parts of the equation right. But there is another essential nutrient being consumed every day that can receive far less attention.

Water.

For Verdyn founder Paul Cox, water has long been part of a much bigger conversation about livestock performance. After more than 30 years working with farmers across Australia, Paul’s approach has become centred around one simple principle: soil, pasture, livestock and water don’t operate independently. What happens in one part of the system inevitably influences another.

“We spend a lot of time looking at what animals are eating, but you’ve also got to look at what they’re drinking,” Paul says.

It is a simple observation, but one increasingly supported by the science of livestock nutrition.

Water is a nutrient, not just a necessity

NSW Department of Primary Industries describes water as an essential nutrient for livestock and says adequate quantities of good-quality water are important for both animal welfare and farm profitability. Its importance goes well beyond satisfying thirst.

In cattle, water is involved in regulating body temperature, digestion, nutrient absorption, metabolism, waste removal and the movement of feed through the digestive tract. It is also fundamental to the environment in which rumen fermentation occurs.

For dairy cattle, the scale of that requirement becomes particularly obvious. According to Dairy Australia, a cow’s body is approximately 60–80 per cent water, while milk itself is around 87 per cent water.

Water is therefore not sitting somewhere outside the nutrition and production equation.

It is right in the middle of it.

What happens in the rumen depends on water

Paul often describes the rumen as one of agriculture’s great biological processors.

“The rumen is the finest compost machine ever built,” he says.

The analogy is a useful one.

Ruminants rely on a complex population of bacteria, protozoa and fungi within the rumen to break down feed that the animal could not otherwise efficiently utilise. Those microorganisms help convert pasture and other feeds into nutrients that can ultimately be used by the animal for maintenance, growth, reproduction and production.

Water is fundamental to that process.

Dairy Australia identifies rumen fermentation, feed movement through the digestive tract and nutrient absorption among the key functions supported by water.

It means looking at livestock nutrition only in terms of what goes into the animal’s mouth can miss an important part of the picture. The animal also needs an adequate supply of suitable water to help process and utilise what it eats.

That connection becomes particularly important as feed changes.

Livestock grazing lush, actively growing pasture can obtain a considerable amount of water from the feed itself. Move those animals onto mature dry pasture, hay, grain or other lower-moisture feeds and their dependence on drinking water increases. Temperature, animal size, pregnancy, lactation and production level can all alter requirements further.

There is no single water requirement that applies to every animal, every paddock and every season.

Feed intake and water intake are connected

This is where water becomes particularly relevant from a production perspective.

Water intake and feed intake are closely related. An animal needs water to support digestion and metabolism, while the type and amount of feed being consumed influences how much additional drinking water is required.

Inadequate access to water can therefore affect much more than thirst.

For a producer concentrating on pasture utilisation, growth rates or milk production, it makes sense to consider whether livestock have the water supply and access required to make the most of the feed available to them.

Dairy systems provide an especially clear example.

Dairy Australia recommends unrestricted access to water day and night and notes that cows can have very high requirements during hot conditions. It advises allowing for up to 250 litres per cow per day in hot weather under high-demand conditions and highlights the importance of sufficient trough capacity and flow rates when many cows want to drink at once.

The important lesson isn’t that every cow will drink 250 litres every day.

It is that water demand can change dramatically, and the system has to be capable of meeting peak demand when it occurs.

Having water isn’t necessarily the same as having enough water

A dam may be full. A trough may have water in it. The farm may have adequate water storage on paper.

But Paul believes the next question should be: what are the animals able and willing to drink?

That brings infrastructure, access and even animal behaviour into the nutrition conversation.

• How quickly does a trough refill?
• Is there enough trough space when a mob arrives together?
• How far are animals travelling to drink?
• Is the water clean and palatable?
• Are animals spending grazing time walking to and from water?
• What happens during a run of hot days when demand suddenly increases?

Dairy Australia recommends multiple water points in paddocks and notes that cows leaving a paddock to find water during hot weather may not return to graze.

In other words, the location and availability of water can potentially influence grazing behaviour as well as water consumption.

For Paul, observing livestock has always been an important part of understanding what is happening on a farm.

“When I go onto a farm, I look at the cows,” he says.

It is an approach that has developed over decades: don’t only look at what has been supplied to the animal. Look at the animal itself. Watch how stock are drinking, grazing, resting and chewing their cud, and consider those observations alongside the pasture, season and nutrition program.

Then there is the quality of the water itself

Quantity is only half the equation.

The quality of livestock water can vary enormously between properties and even between different water sources on the same farm.

Salinity, minerals, algae, bacteria and other contaminants can all affect the suitability of water for livestock.

Agriculture Victoria recommends considering water testing where stock are not performing as expected, when introducing a new water source such as a bore, and following events such as drought, fire or flood that may alter water quality.

Its 2026 livestock water-quality guidance identifies a range of potential issues including salinity, magnesium, nitrates, sulphates, E. coli and cyanobacteria.

Importantly, tolerance also varies between different classes of livestock.

For example, Agriculture Victoria’s published salinity guidelines show different thresholds for beef cattle, lactating ewes and weaners, and mature dry sheep.

That makes water quality another variable worth understanding rather than assuming that because stock will drink a particular source, it is necessarily ideal for production.

The Australian climate makes the conversation even more important

Australian livestock producers understand how quickly conditions can change.

A green paddock in winter and the same paddock in late summer present two very different nutritional environments.

As pasture dries off, the moisture animals receive from their feed falls. At the same time, higher temperatures can increase their need for drinking water.

Lactation adds another layer of demand.

The quality of surface water can also change as dams fall, salts become more concentrated, algae develops or runoff introduces contamination.

This is why water management cannot simply be a matter of calculating an annual requirement and assuming the job is done.

It is dynamic.

Just like pasture nutrition, it changes with the season, the animal and the farming system.

Look at the whole system

This is ultimately where water fits into Verdyn’s broader philosophy.

Paul’s interest in livestock nutrition began more than three decades ago while looking for better ways to address animal health issues on his own farm.

That journey gradually took him backwards through the production system.

If there was a problem showing up in the animal, what was happening in the pasture?

If the pasture wasn’t providing what the animal needed, what was happening in the soil?

And if the soil, plant and animal were being considered together, where did water fit?

The answer was everywhere.

Water moves through the soil. It supports plant growth. It carries nutrients. It is consumed by livestock. Inside the animal it becomes fundamental to digestion, rumen fermentation, temperature regulation, metabolism and production.

That is why Verdyn today talks about soil, stock and water as one farming system, rather than three unrelated areas.

It also changes the questions worth asking.

Instead of only asking whether there is enough feed in the paddock, ask about the quality of that feed.

Instead of only asking whether minerals are being supplied, consider whether they are available and being utilised.

And instead of only asking whether there is water in the trough, ask whether livestock have reliable access to enough good-quality water for the conditions and level of production being asked of them.

None of this diminishes the importance of pasture, energy, protein or mineral nutrition.

It completes the picture.

Perhaps it’s time we looked harder at the trough

For something so fundamental to livestock production, water can be remarkably easy to take for granted.

It is always there - until it isn’t.

Yet the research is clear that water is an essential nutrient, involved in some of the most fundamental biological processes underpinning livestock health and performance.

For Paul, the starting point is characteristically practical.

Walk the paddock. Look at the pasture. Look at the stock.

And while you’re there, take a closer look at the water.

Because better livestock nutrition isn’t only about what animals eat.

What they drink matters too.

Sources & Further Reading

Dairy Australia - Stock Water
https://www.dairyaustralia.com.au/feeding-and-farm-systems/nutrition-management/stock-water

NSW Department of Primary Industries - Water Requirements for Sheep and Cattle
https://www.dpi.nsw.gov.au/__data/assets/pdf_file/0009/96273/Water-requirements-for-

Agriculture Victoria - Water Quality Testing for Livestock, Autumn 2026
https://agriculture.vic.gov.au/support-and-resources/newsletters/sheep-notes-newsletter/autumn-2026/water-quality-testing-for-livestock

Verdyn - Putting Life Back into the Soil: Paul Cox on Three Decades of Farming Differently
https://www.verdyn.com.au/post/putting-life-back-into-the-soil

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