Water is the most essential of all nutrients required by animals. Water functions in the digestion and metabolism of nutrients, elimination of waste products from the body via urine, feces and respiration, transport of nutrients and other compounds into and out of cells, electrolyte balance in the body and as a fluid environment for the developing fetus. A lactating dairy cow has one of the largest requirements for water of any animal. This is because 56 to 81 percent of her body weight is water and she needs to replace the major loss of water through milk production, milk is 87 pecent water, each day (Murphy, 1992). Therefore, it is essential dairy cattle consume adequate quantities of water each day to meet their requirements.
Drinking water is the primary source and method of meeting the daily water requirement with the water contained in feed making a small contribution towards the daily requirement. On average, a lactating dairy cow will drink 95 liters of