Water is the most essential requirement for all live creatures with increased consumption essential in hot summer days ahead.
“When we discuss good horse nutrition, we often fail to recognize the most vital nutrient is water,” emphasized Dr. Thomas R. Lenz, widely recognized equine veterinarian and researcher.
“Without water, horses die within a few days, whereas they may be able to go weeks without food,” Lenz clarified.
An adult horse’s body is composed of roughly 70 percent water. That equates to 770 pounds or 96 gallons of water for the average 1,100-pound horse.
“A horse’s nutritional water requirements are influenced by the horse’s body condition,” Lenz said.
In reality, that includes the amount, type and quality of feed consumed; environmental conditions; and the level of activity or work the horse is doing.
“The type, quality and amount of feed consumed by a horse has a tremendous impact on the amount of water that horse must drink,” according to Lenz.
As a general rule, water intake is proportional to dry-matter intake. “However, the composition and digestibility of the feed is also a factor.” Lenz stated.
“Horses consuming all-hay diets drink more water,” he added emphatically.
In a University of Kentucky study, horses fed all-forages ate 19 percent more dry matter than those fed a mixed grain-hay.
“Those horses drank 26 percent more water,” Lenz pointed out. “The physical form of forages also affects fecal water loss and water consumption.”
In another study, horses fed long-stem alfalfa drank more water than those fed an identical amount of alfalfa pellets.
“Horses on good-quality spring and summer pastures will drink less water compared to horses on hay and grain,” Lenz calculated.
Good-quality pasture forage can be 65-80 percent water, while hay might contain only 8-10 percent or less.
“That’s why idle horses may drink less water in the summer than when winter stalled with hay,” Lenz said.
Their total water intakes might be identical during both seasons but from different sources.
Other factors of the diet, including salt and protein content, also affect the horse’s water consumption.
“We all know that salt consumption increases thirst,” Lenz commented. “But, feed protein intake above the horse’s requirement also increases water intake while the horse voids excess nitrogen via urine.”
Ambient temperature affects water intake. “Horses typically drink less water in cold weather, while heat and humidity increase their water requirements,” Lenz said. “In addition to temperature and humidity, duration and intensity of work can also affect water intake.
“Depending on the conditions in which a horse is exercised, water intake can increase to as high as 30 gallons per day,” Lenz emphasized.
When it comes to water, it is important to remember that all horses need clean, good-quality water available at all times.
“Large, outdoor water troughs should be cleaned at least every couple of weeks to remove debris and algae,” Lenz recommended.
If a horse is stalled, the water buckets should be emptied and rinsed daily of feed and other materials.
“When possible on hot days, provide your horses cool, fresh water, as they drink better if the water temperature is 45-65 degrees,” Lenz advised.