Most dairy farmers underestimate how much water their cows actually need, according to Teagasc’s Ned Loughlin.

“Dairy cows require 10L of water each day during wet and damp weather conditions and during warm summers days the cow’s daily water requirement jumps to 90L,” he said.

The Teagasc Dairy Advisor spoke at a Teagasc/Glanbia Monitor Farm Walk in Monastervin on Tuesday, where he said providing the cow with enough water is important for milk production.

“Farmers should aim to give their cows access to at least 80L of water each day,” he said.

Teagasc research shows that inadequate water intake results in reduced feed intake, poor daily gain and feed conversion along with lower milk production.

Loughlin said that dairy cows can drink up to 14L of water per minute, with 30-50% drank within the first hour after milking.

And as a result, he said it was important to ensure that the water troughs in paddocks are capable of meeting the cows’ water requirements.

Loughlin also said it was a good idea to set up a water trough just outside the parlour, as many cows will be thirsty after milking.

Position of a water trough

The Teagasc Specialist said that farmers should pay particular attention to where there place the water trough in the paddock if they are installing or upgrading their water system.

In an ideal situation the water trough should be located in the middle of the paddock to allow the cows access water from all sides.

Loughlin said that it is a common trend on many dairy farms to see the water trough located at the entrance to the paddock or beside an electric fence.

poorly positioned water trough

Poorly positioned water trough – The electric fence limits the cows access to water.

He said that this increases the amount of walking the cows have to do to access water and this could have a negative impact on soil conditions during wet weather.

Drinking space

Another important factors farmers need to consider is the drinking space available at the water trough, Loughlin said and cows queuing to access water is a sign that there is not enough space for cows to drink.

He said that dairy farmers should allow at least 450mm (18 inches) per cow so that at least 10% of the herd can drink at anyone time.

He said that troughs under electric wires can reduce the drinking space as cows will be reluctant to drink right beside the electric fence.

“Cows rarely stand beside the electric fence all day,” he said.

Flow rate

Another important factor to consider is the flow rate of the water entering the water troughs, he said.

“The hourly flow rate should be at least 13L per cow per hour. The flow rate for a 100-cow herd needs to be about 1,300L per hour or 22L per minute,” he said.

He said that pipe size is critical for flow rate and farmers should aim to use at least an inch and a half pipe to ensure that their cows have an adequate water supply.

small water trough

A water trough which is too small – Signs that cows have moved the trough trying to access water.

Are your water troughs working properly?
  • Cows should not queue to drink at water troughs
  • The trough should always be full after milking
  • No leakage
  • No cow tracks to water troughs – indication of a long walk to water
  • Water systems should be drained over the winter