Livestock Water Requirements

Providing adequate water to livestock is critical for animal health and production. A 10% loss of body water is fatal to most species of domestic livestock.

Water accounts for more than 98% of all molecules in the body and between 50% and 81% of an animal’s total body weight at maturity. Water is required for regulation of body temperature, growth, reproduction, lactation, digestion, lubrication of joints and eyesight.

Livestock water requirements vary significantly depending on the species. Water consumption is influenced by a number of factors, including age, rate of gain, pregnancy, lactation, activity, type of diet, feed intake, environmental temperature and humidity. Livestock obtain water to meet their requirements from wells, fountains, surface water and moisture found in feedstuffs.

Water requirements of beef cattle are a function of the stage of production, lactation and environmental temperature (Table 1). Beef cattle water requirements increase as the weight of the animal increases, during pregnancy and lactation, and with elevated temperatures.

Water requirements also vary depending on the moisture in feedstuffs. Animals fed a diet with higher roughage content have higher water consumption. Limiting water intake reduces feed consumption and animal performance. While diet does influence daily water consumption, the primary factors are temperature and humidity.

Table 1. Estimated daily water intake (gallons per head per day) for beef cows based on temperature
and level of production.

Adapted from Nutrient Requirements of Beef Cattle: Eighth Revised Edition: Updated 2016, 2016, NRC

Water constitutes 87% of milk, and approximately 30% of the water consumed by dairy cattle is lost through milk. Thus, dairy cattle water requirements are strongly influenced by the stage of production and level of milk production (Table 2).

The majority (about 83%) of water consumed by dairy cattle is obtained by drinking, with the remaining from feedstuffs. Water requirements are influenced by the animal’s diet and will increase with increases in dry matter, salt and protein.

Table 2. Water requirements (gallons per head per day) for dairy cows based on level of production.

Horse water intake is highly variable. Water intake is based on body weight, age, diet, exercise intensity and duration, lactation and temperature (Table 3). Horses fed a fiber-rich, forage-based diet require more water than those fed a more digestible grain diet. Horses that are hot from exercise should have steady, but controlled access to water (up to 1-2 liters every 20 minutes) to prevent colic, laminitis and/or exertional rhabdomyolysis (tying up).

Table 3. Estimated daily water intake (gallons per head per day) for horses as influenced by class, activity level and temperature.

Adapted from Nutrient Requirements of Horses: Sixth Revised Edition, 2007, NRC

Table 4 lists water requirements for different categories of sheep. Sheep are able to obtain most of their water requirements from forage consumption. In addition to weight and level of production, water intake also increases in response to increases in environmental temperature.

Table 4. Water intake (gallons per head per day) for sheep.

Table 5 provides water requirements for swine based on level of maturity and weight. Other factors that influence swine water requirements include diet, temperature, housing and feeding methods..

Water intake increases as protein and salt increase in the diet. Swine fed a high-energy diet that are deprived of water (such as can occur during power outages), then are allowed free access to water (power restored), are at risk of salt poisoning (cerebral edema). They should be given access to water sparingly until fully rehydrated.

Table 5. Water requirements (gallons per head per day) for swine.

Limited water access, limited water availability, environmental temperatures, stress and illness can result in dehydration or lack of water. Common signs of dehydration include lethargy, tightening of the skin, weight loss, and drying of mucous membranes and eyes.

Reduced water consumption can be a sign of unfamiliarity, sickness or other stressors. New animals initially may refuse water due to unfamiliarity with water sources and differences in palatability.

Water intake in new livestock should be monitored carefully to make sure they have located the source and are consuming water. With lightweight calves and sheep, be sure the watering source is at an adequate height for access, as animals may not be able to reach it.

Water consumption can be impacted by water quality. Livestock that are provided low-quality water will have reduced water and feed intake, resulting in reduced production.

Certain salts and gases in solution, such as those consisting of sodium, potassium, calcium, magnesium, chloride and sulfate, make water more palatable. However, these same salts and gases can be toxic if present in excess. For more information, refer to NDSU Extension publication AS1764, “Livestock Water Quality.”

Livestock should never be forced to drink dirty or contaminated water. Dirty or stale water can reduce water consumption. Providing grazing livestock with fresh water has been shown to increase weight gains.

Dirty water is a host for disease organisms. Disease can spread rapidly if animals drink from the same water source, so sick animals should be isolated, and waterers cleaned frequently.

Waterers can be disinfected with a dilute bleach solution following cleaning. A dilute bleach solution of 2 to 3 ounces per 50 gallons of tank capacity, with the bleach containing 5.25% sodium hypochlorite, applied weekly, will also suppress algae growth.

Proper installation of the waterer or tank base will prevent fecal contamination of water. The base should be wide enough so animals can place their front legs on it easily while drinking, but not their hind legs. This will keep animals from defecating in the water.

Water is an important but often overlooked nutrient. Livestock water requirements are affected by many factors, including, size, productivity, diet and environmental conditions. Good water quality and cleanliness can increase water intake and improve livestock production. Limited access or reduced water consumption can result in dehydration, which can be fatal to livestock.

This publication was authored by Miranda A. Meehan, Extension Livestock Environmental Stewardship Specialist, Gerald Stokka, former Extension Veterinarian/Livestock Stewardship Specialist, and Michelle Mostrom, Veterinary Toxicologist, 2021.