Water Requirements for Cattle

Water Requirements for Cattle



Water is one of the most essential elements required for a balanced diet.  It is required for regulation of body temperature, growth, reproduction, lactation, digestion, and other body functions.  Any reduction in water intake will reduce metabolic functions and performance. The severity of this production loss is directly related to the level of water deprivation.   As little as a 10 percent loss of body water can be fatal to many livestock species.  This paper is a reminder of the importance of water and our need to ensure an adequate amount of clean water is available to maximize production efficiency.


In general, it takes 1 gallon of water per 100 pounds of body weight at temperatures below 60° F.  As temperature increases, water requirements can be as much as double to 2 gallons per 100 pounds of body weight.   If water is restricted, cattle begin to slow down metabolic processes to match water available.  Dry matter intake and fermentation rate begins to slow as water intake is restricted, resulting in a decline of potential productivity Therefore, it is important to have adequate water available.  The following table is based on water requirement equations adapted from Winchester and Morris (1956) as adopted by 2016 NRC.  This table shows the daily water required for 100 head of cattle.


Receiving pens should have at least ½ of the water requirement for the cattle available at one time.  For example, 100 calves weighing 400 pounds starting on feed in 70° temperatures will need to have at least 300 gallons of water available.  This will allow the cattle to fill up with water upon arrive at the facility.  The faster the cattle get hydrated the quicker the cattle will get calmed down, rest and start eating.


Cattle on lower energy grower diets require less water than cattle on higher energy finishing diets.  This is due to higher metabolic activity with the higher energy diets.  If water is limited, then metabolic activity will drop to match water availability.  Keep in mind as cattle are on feed during the summer months, water requirements will double as temperatures increase from 60 to 90 degrees.  Make sure that when estimating water needs during the hot summer months to estimate maximum body weight during that time to ensure adequate water is available.  In time of heat stress, drinking water can be the most efficient and fastest way for cattle to reduce body temperature.


Water quality can also be an issue.  In areas with high sulfur water, intake can be reduced. An alternate water supply of high quality may be essential during this time. Sulfates and nitrates are common problems for water quality. The safe upper limit for sulfate for calves is less than 500 ppm (167 ppm sulfur as sulfate).  For adult cows, the upper limit is less than 1,000 ppm (333 ppm sulfur as sulfate).  A safe level of nitrate nitrogen (NO3-N) in the water is less than 100 ppm for cattle.


In conclusion, adequate water supply is essential for efficient production.  The amount of water available per day is important to keep all cattle hydrated.  As cattle increase is size, daily water requirements for the pen will increase.  Ambient temperature will increase water requirements faster than any other factor.  Check to ensure that water systems can keep up with demand as the cattle grow and temperatures increase during the summer months.


All information provided from Purina products Technical Soutions