6 tips on delivering water for dairy cows

Many dairy farms have outgrown their water supply as they have increased cow numbers. Yet investment in water infrastructure often is not considered until a problem arises.

Phil Evans is director of Agriplumb, an agricultural plumbing business specialising in dairy and poultry. He says:

“Historically, most dairy farms were set up for 150-200 cows, and they’re now running more cows on the same infrastructure, which is not up to the job. 

“Usually, we get called in because farms can’t move enough water fast enough to service the cows.” 

See also: Advice on observing housed cows to improve dairy sheds

Typically, low water levels arise when cows queue at empty water troughs that cannot refill quickly enough and, out of frustration, cows then break ballcocks.

Ultimately, reduced water intakes affect milk yields, cow health and fertility.

“Milk comprises 87% water, but the problem is twofold – if cows are waiting for water, they are not eating, which depresses milk yields,” says Phil.

In addition, water requirements increase substantially in times of heat stress, exacerbating any water supply issues.

“A cow giving 25 litres requires 50-60 litres of water daily. On a hot day, this can increase to 100 litres-plus.

“And a Holstein cow being milked three times daily will drink 100-plus litres on a normal day, and 150-160 litres when it is hot,” he explains.

“The problem is that on hot days, you need to move twice as much water.”

Below, Phil gives advice on improving the water supply for grazing and housed cows.

1. Survey existing infrastructure and check water flow rates

Farm water can be supplied via boreholes, springs or mains water. Regardless of supply, having a backup is essential in case the first one fails.

Farmers should check their current flow rates by filling a jug or bucket with water and recording how quickly it fills. The target should be 100 litres a cow a minute.

“It’s common to see existing flow rates under 30 litres/minute. As most cows drink after milking, an insufficient water supply means losing valuable time when cows should be eating,” Phil points out.

2. Storage

Water storage tanks are essential so farmers have a buffer in case of a breakdown or to deal with peaks in demand © Phil Evans

Using storage tanks is vital to create a buffer in case of a breakdown and deal with peaks in demand.

“On average, cows drink 40% of their daily water requirement after the first milking and 60% after the second. On three-times-a-day milking, it’s more evenly split,” he explains.

Farms should have enough storage for at least one day’s supply.

Tank capacity will depend on herd size, but at recommended flow rates of 100 litres/minute, 300 cows will need a storage capacity of 30,000 litres, for example.

Storage tanks can be situated anywhere on the farm where it is convenient to locate a pumping system.

Phil recommends having three tanks: one for cow drinking water, a second to service the plate cooler, and water from the second tank returning via the plate cooler to a third tank to be used for washing down.

Furthermore, a tap should be fitted between each tank to access water in an emergency.

3. Water pumps

While increasing the pump capacity alone can relieve pressure, some farms require a whole new water system. “You need the right pump for the right job,” Phil stresses.

Pumps should deliver the correct pressure and flow rate and be compatible with the farm’s existing system.

“For example, a low-pressure, high-flow pump is designed for washing down, but you need a high-pressure and high-flow pump to push water uphill,” he says.

He advises using variable-speed control pumps that run at the correct speed to maintain the desired pressure and flow rate. This is not only more efficient, but also more economical.

They also deliver a “soft start” that ramps up and down slowly, reducing wear and tear on the pumps.

He also recommends using a twin setup (having a spare that runs on a duty and assist programme). “If one fails, you are not left high and dry, and the second will kick in to assist the first.

“Whether using a single or multi-pump system, it is essential to include a dry-run system, so the pump shuts off if you have no water.

“Pumps require a water flow to keep cool when running and can be damaged or completely wrecked if they run without water, even for a few minutes.

“I would encourage farmers to use a low-water-level alarm system. This is usually a float in the storage tank, which triggers an alarm when water levels drop.”

Variable speed control pumps are more efficient and economical © Phil Evans

4. Are pipe sizes sufficient?

Even with the right pump, pipe size may be limiting performance.

Traditionally, most dairy farms have small pipes with an outer diameter of 20-32mm. However, modern farms should have 40-63mm pipes to achieve good water flow while minimising electricity use.

“You can only ram so much water up a small-diameter pipe. You can increase the pressure, but you come to a point where it physically can’t send any more water,” says Phil.

He suggests when updating water infrastructure – which may happen only once every 30 years – farmers should increase the size of their system by 20% to allow for expansion.

He also strongly advocates using ring main systems that can be easily extended.

Ring mains allow tanks to be fed from two directions, which increases flow rates. (A single-leg system can only supply water from one point.)

“I even put washdown systems on a ring main because it means if you use more than one hose, you get good pressure to both,” he says.

“You use more pipe on a ring main system, but in the grand scheme of things, pipe is relatively cheap compared with the excavation required to bury it.”

He says the pipe should be pressure tested using water or compressed air to check for leaks before it is covered with concrete or tarmac.

When digging across a road, 100-150mm plastic ducts should be used in case more pipework or electric wires are required in future.

“Human memory is short, and all pipes, ducts and cables should be documented for future reference,” he adds.

5. Troughs

Troughs are best placed on crossovers between cubicles and at parlour exits, because these are peak drinking places. At least 10cm a cow should be provided.

When cows are grazing, each paddock must be serviced by at least one trough, which should be located within paddocks rather than in gateways beside hedges, to give cows unimpeded access.

“Position is essential. You don’t want them placed too far away from the entrance. More cows can drink from a tank’s perimeter if it is not placed against a hedge, and it avoids contamination,” Phil advises.

“Field tanks should also be fitted with fast-flow valves because tanks are big and need to be filled quickly.”

Consider using water troughs that are easy to empty and clean © Phil Evans

6. Water treatment systems

Water can be treated with minerals such as magnesium (to prevent milk fever and staggers, for example).

However, Phil warns that the farm’s water supply must be closed, and any farmhouses must run on a separate water supply to prevent contamination.

“Any private supply should also have a UV filter unless supplied by mains water,” he adds.