Water | The Most Important Nutrient for Horses

Water is the most essential nutrient that we provide for horses on a year around basis. Horses need 2 to 3 times more water than other feedstuffs. An 1100 lb horse on a dry forage diet at an average temperature of 68 degrees Fahrenheit will need a minimum of 6-7 gallons of water per day or 48-56 lbs of water, and many horses will drink more water than the minimum. We all appreciate that the water requirement may double at high temperatures but may not realize that at -4 degrees Fahrenheit, the quantity required is about 10-12 gallons per day, or higher than at moderate temperatures. The onset of cold weather can increase the requirement for water because there is no fresh grass, and the air is arid.

There is a misconception that domestic horses can quickly eat enough snow to survive. While horses in the wild do adapt to lower water intakes, partially because food intake is also frequently reduced, horses can survive longer without food than water. Reduced water intake can also impair digestion and potentially contribute to the incidence of impaction colic.

It also requires a great deal of energy to eat snow, melt the snow in the body and raise the fluid temperature to an average body temperature of 99.5- 100.5. Increasing the temperature of 10 gallons of water from 32 to 100 degrees takes about 1372 Calories or about the amount of digestible energy in a pound of feed. Melting the snow to get to water will take much more power, and the horses will not readily eat a pile of snow the size of 20 five-gallon buckets. It takes about 10 inches of snow to have one inch of water.