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Water intake determines a dairy cow’s feed intake and milk production

Donna Amaral-Phillips Published on 21 December 2010

Water is essential for life and is the nutrient needed by all mammals in the largest quantity. Water is important for various body functions, in temperature control, and in the production of milk. Milk contains 87 per cent water.

Limitations in availability of clean, fresh, and high-quality water can limit milk production quicker than a deficiency in any other nutrient. Water intake also regulates feed intake.



Thus, understanding the importance of water and how to effectively manage your dairy feeding system to provide adequate water intake is very important. Important management concepts to achieve this objective include the following.

  • Milking dairy cows consume 4 to 5 kilograms of water per kilgram of milk they produce. Of this amount, drinking water provides 80 to 90 per cent of these needs, with the remainder coming from moisture found in feeds.

For example, a Holstein cow producing 27 kilograms of milk would drink approximately 95 to 115 litres (25 to 30 gallons) of water daily. Dry dairy cows will consume 38 to 57 litres (10 to 15 gallons) of water daily.

  • Temperature and humidity dramatically increase water needs. Cattle under heat stress (temperatures above 21ºC (70ºF) or higher humidity could lower this temperature) require 1.2 to 2 times more water than cattle housed under thermal-neutral temperatures and humidity.

  • Water troughs should be fitted with non-backsiphoning valves and an outlet (which is not accessible by cattle) for easy removal of water and sediment in the tank.

  • Waterers should be emptied and cleaned (scrubbed) with a weak chlorine solution (1/2 pint of household bleach per 20 litres of water) at least weekly to improve water quality and animal acceptance. This solution should be removed from the waterer and replaced with clean water.

  • Waterers should be sized to accommodate multiple animals. Recommendations are for one waterer or 2 feet of water trough perimeter space per 15 to 20 cows in the barns.

  • Milking cows consume water alternately with feed and shortly after being milked. Thus, waterers should be located within 50 feet of the feedbunk and in return alleys or areas where cows are housed directly after milking. Waterers should be located close to cows housed in freestalls, composed bedded pack barns, loose housing or on pasture.

  • Waterers should be located in areas immediately accessible upon return from the milking facilities. Waterers should be sized to accommodate the number of cows released from the milking parlour at one time.

    Dairy cows drink 50 to 60 per cent of their water needs immediately after milking. There should be 1 to 2 feet of linear trough space per cow in return alleys from the milking facility.

  • Cattle spend approximately six hours per day eating but only about 20 minutes daily drinking water. So the flow rate of water into the waterer is very important in providing adequate water intake. Potential problems of stray voltage should be investigated if cattle lap water from the waterer.

  • The depth of water within the trough should be such that cows can submerge their muzzles 1 to 2 inches into the water and drink without gulping air. Water depth should be a minimum of 3 inches, with shallow water depths of 3 to 8 inches being preferred.

  • The water surface of water troughs should be 2 to 4 inches below the top edge, with the height of the trough being 24 to 32 inches for Holstein cows (2 to 3 inches lower for Jerseys).  PD

—Excerpts from Kentucky Dairy Notes August 2010

Donna Amaral-Phillips
  • Donna Amaral-Phillips
  • Dairy Nutrition
  • University of Kentucky