How it takes 6.4L of water to produce 1L of milk
On average 6.4L of direct water is used for every litre of milk produced, according to Eleanor Murphy a Walsh Fellow at Teagasc.
This level of use is driven by consumption by livestock and miscellaneous use, plate cooler water use and cleaning procedures in the parlour.
Presenting a paper this week on water use on Irish dairy farms at the Teagasc National Agri-Environment Conference in Tullamore Murphy said with the abolition of EU milk quotas in 2015 and Irish government strategies such as FoodHarvest 2020 there will invariably be increased pressure on freshwater resources.
With increased production, she said, there will be a great need to develop and promote sustainable Irish dairy production.
“Proving sustainable water use through a water footprint will be important metric making Ireland’s dairy exports more attractive to consumers on the global market,” she cited.
In her paper Murphy said fresh water demands for animal maintenance is determined by climate, dry matter intake and milk yield and varies from year to year.
In releation to water use in the parlour, she said Teagasc recommend an optimum plate cooler ratio of water: milk of 2:1 for optimum energy consumption.
“Milk cooling procedures using a ratio 2:1 or higher demand 56% less energy to cool milk than plate coolers which use <2:1 L water /L milk,” she said.
According to Murphy this can be collected and reused for wash-down procedures and for animals drinking.
Murphy also said another aspect to consider in efficient water use is the maintenance of the water supply network on a farm.
“Leaks which go unchecked can add to the pumping cost of water on a farm. A leak of 10L/min could cost up to €526/annum in pumping costs. A hot water leak of 60mL/min (1 drip/sec) could cost up to €240/annum in associated pumping and heating costs,” she said.
Murphy commented that a greater understanding of water use and the drivers of water use on farms gives an insight that enables the Irish Dairy sector to reduce its burden on freshwater resources.