Water Systems for Growing Swine

by 5m Editor
22 August 2005, at 12:00am

Abstracted from “Water Systems for Swine” by Mike Brumm, 2005 Pork Academy, Des Moines, Iowa and published by North Carolina State University - Water is the nutrient that swine require in largest quantity, but compared to the other nutrients supplied by feed, it is the most frequently misunderstood and mismanaged.

Water Systems for Growing Swine - Abstracted from “Water Systems for Swine” by Mike Brumm, 2005 Pork Academy, Des Moines, Iowa and published by North Carolina State University - Water is the nutrient that swine require in largest quantity, but compared to the other nutrients supplied by feed, it is the most frequently misunderstood and mismanaged.

While various sources recommend that water be available free choice, most fail to offer specific c recommendations as to number of drinking spaces, drinker type, and delivery rate of drinkers. They also fail to specify quality parameters.

In contemporary swine production facilities, decisions must be made concerning all of the above. In addition, the cost of water acquisition and the storage and disposition of wasted water have led producers to seek a better understanding of the water needs of pigs.

At birth, water accounts for 82 percent of the pig’s empty body weight. By the time the pig weighs 240 pounds, water comprises only 51 percent of the empty body weight. In addition to body tissue and metabolic functions, water is used for a) adjustment of body temperature, b) maintenance of mineral homeostasis, c) excretion of the end products of metabolism (particularly urea), d) achievement of satiety (gut fill), and e) satisfaction of behavioral needs.

Nursery and grow-finish

Water consumption for growing-finishing pigs has a distinct periodicity. When nose operated drinkers are used, there is a peak at the beginning of the feeding period and at the end. Between feeding periods, water consumption peaked two hours after the morning feeding and one hour after the afternoon feeding. Weaned pigs housed under conditions of constant light showed a diurnal pattern for water intake, with higher consumption recorded from 0830 to 1700 hours, compared to 1700 to 0830 hours. Grow-finish pigs using nipple drinkers showed a large peak from 1500 to 2100 hours and a smaller peak between 500 and 1100 hours.

The number of pigs in a group (pen) apparently influences water usage, too. In one study, water usage was higher when pigs were housed in groups of 60 versus groups of 20. When group size increased, total drinking time per pig decreased, even though the number of pigs per drinker was the same for both group sizes.

Water:feed ratios for liquid feeding systems typically range from 2.5:1 to 3.5:1. Recently, water:feed ratios ranging from 1.78:1 to 2.79:1 for pigs weighing from 40 to 250 pounds and fed dry feed ad libitum have been reported. The lowest reported water:feed ratios were with wet/dry feeders and bowl drinkers, whereas gate-mounted nipple drinkers had the highest ratios. With similar performance, this suggests that the major cause of differences in water:feed ratios between the various drinking devices is due to differences in water wastage, not differences in the amount consumed.

Water:feed ratios decrease as pigs grow. For example, in two experiments, water:feed ratios with gate-mounted nipple drinkers were 3.35:1 for 40- to 55-pound pigs, declining to 2.27:1 and 2.58:1 for 209-pound pigs. When pigs were given water only in the feeding trough using a commercially available wet/dry feeder, water:feed ratios declined from 2.11:1 to 1.50:1; when pigs were offered water using a bowl drinker, the ratios declined from 2.11:1 to 1.77:1. Recent on-farm data support the conclusion that water:feed ratios decline as pigs grow, with a ratio as low as 1.5:1 common in facilities that use wet/dry feeders or stainless steel bowl drinkers in late finishing. Assuming similar water:feed ratios for both barrows and gilts, it follows that barrows drink more water than gilts since barrows eat more feed per day than gilts in mid to late finishing. Pigs fed meal diets drink more water than pigs fed pelleted diets, reflecting similar water:feed ratios and differences in feed conversion efficiency.

General recommendations exist for the number of pigs per drinking device, but research to support these recommendations is limited. Researchers using 3- to 4-week-old weaned pigs reported a slight reduction in average daily gain and an increase in weight variation within pens of 16 pigs given access to one versus two nipple drinkers for five weeks post-weaning. Generally, for groups larger than 10 pigs in a nursery and 15 to 20 pigs in a grow-finish facility, a minimum of two delivery devices are recommended.

Grow-finish pigs spent from 3 to 16 minutes per day at nipple drinkers when flow ranged from 1,100 milliliters per minute down to 100 ml/min. This suggests pigs will exert some extra effort in order to obtain water, but it is not clear at what point having to wait for drinker access or exert extra effort impairs performance.

Flow rate recommendations

How fast should water flow from drinking devices? In one study, the drinking speed of grow-finish pigs was 1,422 ml/min of actual water intake at a nipple drinker where the flow rate was 2,080 ml/min. This represented a 23.2 percent spillage rate, versus an 8.6 percent spillage rate when the flow rate was 650 ml/min. A minimum delivery rate of more than 250 ml/min was advised for grow-finish pigs, and a rate of 1,000 ml/min appears to be more than adequate.

Research supports the conclusion that one nipple drinker per 16 to 22 pigs is inadequate. These results are in contrast to the conclusions that providing one versus two nipple drinkers per 20 grow-finish pigs does not affect drinking behavior, social behavior, or production.

Number of drinkers

Table 1 lists the number of pigs recommended per drinker and suggests drinker height when gate-mounted nipple drinkers are utilized. Note that these height recommendations are appropriate for nipple drinkers mounted at a 90-degree angle. When mounting brackets with 45-degree angles are utilized, greater heights are necessary in order for the pig to manipulate the drinker and minimize water wastage. When swinging drinkers are used, they should be adjusted to a height of 2 to 3 inches above the back of the pig and readjusted every two to three weeks as the pigs grow.

With wet/dry feeders, the general recommendation is to allow up to 12 pigs per feeder space. There are no data available to suggest an appropriate stocking density for tube feeders or bowl drinkers. Many manufacturers recommend no more than 20 to 25 pigs per bowl drinker.

Table 1. Nipple drinker stocking and height recommendations
12-30 lb 30-75 lb 75-125 lb 125 lb+
Pigs/nipple 10 10 12-15 12-15
Height, inches 6-12 12-18 18-24 24-30

Water supply

Water also must be available for cleaning and other uses in swine facilities. As facilities have grown, issues associated with the size of the water supply lines have become more critical. For example, consider the water delivery system for a 1,000-head finishing facility that has 20 pens on each side of a center aisle. Each pen will have two nipple drinking devices. If all the nipples on one side of the aisle are being used at the same time, this would be 40 drinkers that must have water. Assuming 4 cups per minute flow from each drinker, the total water flow from the supply line would need to be 10 gallons per minute (4 cup/ min x 40 drinkers = 160 cup/min = 10 gal/min). If the water flow is any less, one or more drinkers may develop a reduced flow rate or even experience no flow when a pig attempts to drink.

Water supply lines should be sized to have friction losses of less than one pound per square inch (psi) per 100 feet of pipe and flow velocities of less than 4 feet per second. Thus, in order to supply 10 gallons per minute, the pipe must have an inside diameter of one inch (Table 2).

Table 2. Water flow (gal/min) from various pipe diameters, assuming 4ft/sec flow and no pressure losses due to friction, elbows etc.
Pipe inside diameter 0.50 0.75 1.00 1.25
Flow, gal/min at 4ft/sec 2.50 5.50 9.80 15.30

Water and manure

In addition to providing for the pigs’ needs, decisions on water delivery devices increasingly must take into account manure storage and land application issues. Researchers have demonstrated no difference in grow-finish pig performance between water provided in a wet/dry feeder versus water offered via a gate-mounted nipple drinker. Yet, using a wet/dry feeder in one summer trial resulted in a 30 percent reduction of total manure. In a winter trial, a 14 percent decrease in manure volume occurred with a swinging drinker versus a gate-mounted nipple drinker, and a 25 percent decrease in water usage occurred with a stainless steel bowl drinker versus a swinging drinker.

Production systems that store manure in deep pits under fully slatted floors are selecting drinker devices that limit the amount of water wastage (and resultant manure volume) in order to increase the amount of available manure storage capacity. Water usage is in the range of 1 gallon per grow-finish pig per day with wet/dry feeders and bowl drinkers and 1.5 gallons per pig per day with gate-mounted nipple drinkers. Manure production patterns follow water usage.

While manure volume varies with water wastage, the total nutrients (N, P, and K) in the manure do not. Even though there is less total volume of manure to deal with when drinkers that minimize water wastage are used, the total amount of land needed for responsible land application of the collected nutrients does not vary, just the amount applied per acre. In addition, when water wastage is minimized, the stored manure can have dry matter concentrations as high as 8 to 10 percent. This compares to manure in deep pits having dry matter concentrations in the range of 3 to 4 percent when pigs used nipple drinkers. This difference in dry matter content means different equipment may be needed to agitate, load, and apply the liquid manure, depending on the drinking device.

In production systems where manure is stored in a lagoon and applied with irrigation devices, water savings associated with drinkers are of less concern. In fact, water wastage from drinker devices may make manure flow easier through pipes to the lagoon. The waste water also contributes to a more dilute lagoon effluent, reducing the risk of odors from the manure storage device.


A pig will drink from a variety of devices. The amount of water needed daily by the pig depends on numerous influences, including temperature, feedstuffs, stage of production, and health. Within a 24-hour period, swine demonstrate a peak in water usage in late afternoon. Daily water needs for pigs range from less than 0.5 gal/pig/day for newly weaned pigs to more than 1.5 gal/pig/day for grow-finish animals using nipple drinkers. Daily drinking water usage over time can be used as a predictor of swine health.

Reproduced Courtesy

Source: North Carolina State University Swine Extension - July 2005