Do you know if your cows are getting enough water?

While dairy cow numbers have increased on some farms, drinking troughs in many cases have not.

As a result, drinking trough size and/or poor flow rates are incapable of meeting the cows’ water requirements.

This is an issue on many dairy farms, with Teagasc research showing that inadequate water intakes result in reduced feed intake, poor daily gain and feed conversion along with lower milk production.

On warm days the cows requirement for water dramatically increases, particularly after milking when she will consume 30-50% of her water intake.

According to Teagasc, on a “cold wet day dairy cows require 10L of water and during a warm sunny day a cow’s daily water requirement jumps to 90L”.

Trough capacity

Troughs which are too small for the required herd result in an inadequate water reserve, bullying at drinking and a drop in milk yield.

Teagasc recommends 9L/cow (two gallons / cow); or, in order words, 1,350L (300 gallons) for 150 cows.

Troughs should also be ideally located in the centre of the paddock to minimise the cows’ walk for water and to avoid cows crowding at gaps – causing damage and delays when cows are exiting the paddock.

Flow rate

Dairy cows can drink up to 14L of water per minute. Therefore, the rate in which the water enters the drinker is important to consider.

Assuming the daily demand is 70L/cow and almost 50% is consumed in the three hours after milking, an hourly flow rate of 12L/hour is required.

For a 100-cow herd this means 1,200L/hour or 20L/minute.

How to check flow rate:
  1. Mark the level of water in the drinker;
  2. Tie up the ballcock and empty 20L from the drinker;
  3. Release the ballcock and measure how long it takes to fill to the mark;
  4. Divide 20L by the time taken to refill.

If the flow rate is less than that which is required for your herd, then your water supply system needs to be improved.