A good water system is needed on all farming enterprises, but particularly on dairy farms. It can be hugely important to have it right – especially at pressure points during the main grazing season, when the weather gets warm.

Warm weather, like we saw last weekend, can put pressure on water systems on farms and generally, if your water system is under pressure, a queue for the water trough will be a good indication of that.

According to Teagasc, on an average day, a 150 cow herd could drink up to 10,000L of water (roughly 65L per cow).

A cow’s water intake could range from 10L on a cold day to 90-140L on a warm, sunny day, so at certain times of the year, the demand for water on dairy farms can be huge.

With the rapid expansion of dairy herds right across the country, the water systems on some farms may need to be upgraded if cow numbers have expanded in a big way.

Furthermore, a large proportion of a cow’s water intake will take place during the first few hours after milking, which will put a considerable strain on a water system that isn’t designed to serve a large number of cows in such a short space of time.

Milk production and the health of the animal can be affected if the water supply is inadequate.

It is advised to allow 450mm (18in) of drinking space per cow. Main pipelines should be at least 25mm or 32mm, and 38mm or 50mm for larger herds.

Some farmers may see merit in simply putting in a larger water trough; however, this is likely to just prevent bullying at the trough by allowing more cows access to drink from it, but it won’t solve the issue of a poor water supply feeding into the trough.

Checking water flow rate

According to Teagasc, 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 the 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 what is required for your herd, then your water supply system needs to be improved.

WATER SUPPLY