Water needs of pigs
Pigs must consume enough water to balance the amount of water lost.
Why is water so important? Water is the nutrient that is required in the largest quantity by swine and is the most essential nutrient for life. In turn, water fulfills many physiological functions ranging from giving form to the body, playing a crucial role in temperature regulation, movement of nutrients to cells of body tissues and lubrication of the joints. Water may very well be the most frequently misunderstood and mismanaged nutrient when compared to other nutrients supplied by feed. Therefore, when making decisions involving swine production facilities, there are several factors such as sources of water, estimated water requirements, flow rate recommendations, drinking spaces, number of drinkers, water supply and water quality that should be considered.
Pigs obtain water to meet physiological needs such as growth, reproduction and lactation from three main sources. These sources include water from feedstuffs, water from metabolic processes and drinking water. Feed ingredients that are most commonly used in swine diets typically contain about 10 to 12% water (NRC 1998). Metabolic water originates from the breakdown of carbohydrates, fat and protein. However, drinking water is by far the major and most important source of water for swine, even though metabolic water and water contained in feed reduce the amount of water that the pig must drink to meet its daily requirements.
How much water do pigs need? Pigs lose water through four routes: kidneys (urination), intestines (defecation), lungs (respiration) and some through evaporation (skin- sweat glands are largely dormant). Therefore, pigs must consume enough water to balance the amount of water lost. Care must be taken when determining water requirements for pigs, because true water usage is generally overestimated. Wastage is generally not taken into account, therefore realize there is a difference between water consumption and water disappearance (animal intake and waste).
Current research information provides only estimated water requirements because there are many different factors that can influence the amount of water required by pigs on a daily basis. The factors that may influence the water requirements of swine include: feed intake, ingredients in the diet, temperature, state of health and stress level. Water needs may vary as much as 50% due to some of these factors. In turn, only estimates of water requirements are reported. As a general rule: pigs will consume 1.5 to 2 times more water than feed.
Estimated water requirements of swine.
Class of Pig Gallons/pig/day
Nursery (up to 60 lbs.) 0.7 - 1
Grower (60 – 100 lbs.) 2 - 3
Finisher (100 – 250 lbs.) 3 - 5
Non-pregnant gilts 3
Gestating Sows 3 - 6
Lactating Sows 3 - 7
Source: National Pork Board, Swine Care Handbook (2003 Edition)