Provision of Water for Swine

Livestock Update, July 2006

Allen Harper, Extension Animal Scientist, Swine, Tidewater AREC

Recently 4-H and FFA members toured the 1200-sow farrow-to-wean swine operation at Sunset View Farm near Zuni, Virginia. Farm Manager Dave Tribby asked the enthusiastic group of participants “if one of these sows does not eat her daily ration of feed, what is the first thing you should check?” The youngsters gave some thoughtful answers such as “take her body temperature” or “check the feed quality.” But no one gave the answer Mr. Tribby was looking for. He went on to explain that there were a number of possible reasons why a sow might go off feed, but the first thing that should be evaluated is the water nipple to make sure that it is not occluded and the sow has access to all the fresh water she chooses to drink. This teachable moment reminded me of how drinking water is often referred to as the most essential nutrient, but also how easily the importance of water can be taken for granted. Whether it is with a set of 4-H project pigs or on a 2400-sow commercial farm, provision of drinking water is critical to health and good performance in swine. The following outlines the basis for the importance of swine drinking water along with some practical recommendations.

The physiological purpose of water is extensive. The presence of water in cells allows for the shape, form and function of body organs and structures. It is the medium in which cellular metabolic reactions occur and allows for nutrient transfer and waste product removal. It is involved in body temperature regulation, lubrication of the joints (via synovial fluid) and protection of the nervous system (via cerebrospinal fluid). Water makes up a major portion of the total body composition of pigs and the proportion of water in the body changes with age. It constitutes over 80 % of the body weight of a 1-day old pig, but in a 5-month old market hog water makes up about 50 % of body weight (reviewed by Thacker, 2001).

In terms of volume, drinking water is by far the most important source for meeting the pig’s water requirement. But it is not the only source. Pigs derive minor amounts of their water requirement from moisture present in typical feed ingredients (usually about 10%) and so-called “metabolic water” that is actually produced in the pig’s body during metabolic reactions.

Under normal circumstances the amount of water excreted from the pig’s body is remarkably balanced with the amount of water consumed. One exception to this is excessive water losses during gastrointestinal problems that cause diarrhea. Indeed during severe cases of diarrhea in young pigs, it is not the gastrointestinal disease organism that is directly responsible for pig deaths but rather the severe dehydration that is caused by the associated diarrhea. In order of magnitude, water is excreted from the pig by routes of urination, in the feces, from the lungs during respiration and from the skin by evaporation. This latter route of water excretion is very minor in pigs because of the lack of functional sweat glands. It is this unique characteristic that causes pigs to seek a means of wetting their skin during periods of heat stress.

Setting precise water quantity requirements for different age and production classes of pigs is not fully meaningful, because so many factors directly influence water needs and consumption. For example increased environmental temperature, increased protein, salt or fiber content of the diet and reduced relative humidity all increase water requirement and consumption by pigs.

For this reason ad libitum or free choice access to water is recommended.  The following table summarizes typical water consumption rates by various classes of swine.

There is a very close relationship between feed consumption and water consumption. As feed consumption increases, the pig’s water requirement and consumption increases. In situations in which the pig is unable to consume adequate water there is a concomitant reduction in feed intake. This very relationship is the basis for Dave Tribby’s question to the 4-H and FFA youth visiting his sow farm. If sows or growing pigs reduce feed consumption, the first thing that should be ruled out when determining the cause is if the water provision system is performing properly. English swine researchers (Brooks and co-workers, 1984) have demonstrated that water intake by pigs can be predicted quite accurately based on feed consumption using the following equation.

Water consumption (Liters/day) =

0.788 + (2.23 x Kg of daily feed intake) + (0.367 x Kg pig body weight^0.06)

In the mid-Atlantic region, most swine farms depend on commercially dug wells as the drinking water source. Under these circumstances cases of water quality problems that cause health or performance problems in swine are rare. However, a general understanding of water quality is important to assure that quality does not impair performance or consumption. One crude measure of water quality is TDS or “total dissolved solids” which is a measure of the total quantity of mineral matter dissolved in water. Less than 1000 ppm TDS would be considered completely safe but pigs can adapt and have been reported to tolerate levels up to 7000 ppm. At high levels, sulfates in drinking water can cause loose stools in weanling pigs, but again the ability of the pig to adapt to high-sulfate water is good. Nitrate and its more toxic conversion product nitrite are indications that some nitrogen entry into the water source has occurred and therefore are considered as indicators of drinking water quality. Other minerals present at elevated levels in water, such as calcium or iron, may not have direct health effects on pigs but can cause scale or slime build-up that can clog screens in water nipples and valves.

The following table provides some general guidelines for swine drinking water quality. The upper limit values are considered conservative limits based on reports of the Council for Agricultural Science and Technology (CAST, 1974), National Academy of Sciences (NAS, 1974) and the Canadian Council of Resource and Environment Ministers (CCREM, 1987).

Suggested Water Quality Assessment Factors for Swine Drinking Water

Measurement or ionic concentration:	Conservative Safe Level (ppm)*
Total dissolved solids (TDS)	< 3000
Nitrates	< 100
Nitrites	< 10
Sulfate	< 1000
Bicarbonate	< 1000
Calcium	< 1000
Magnesium	< 400
Copper	< 5

* Conservative limits taken from CAST (1974), NAS (1974) and CCREM (1987).

A practical decision made by swine producers and managers is the type of water delivery system that is installed, either in new construction or when remodeling and replacing worn equipment. Pig drinkers are available in a variety of types and styles and are manufactured in sizes specific for different weight or age classifications of pigs. General categories include nipple drinkers, bite valve drinkers and bowl- or cup-type drinkers. All are effective if installed properly and adjusted when necessary as pigs grow. The ultimate decision of the type or types of drinker devices installed will be dependent on producer goals in terms of costs, maintenance, and desired characteristics. For example nipple drinkers are a bit less expensive than bite valve drinkers but can have more water waste. With both nipple and bite valve drinkers, water waste is reduced when they are mounted at a level 4 to 6 inches above the pig’s backline. Water wastage is even less with more expensive bowl- or cup-type drinkers. All three types can be securely mounted on pen panels that separate pens.

In addition nipple drinkers are sometimes suspended above finishing pens with a flexible supply line and chain. These “swing-type” drinkers can help reduce water waste and wear and tear on pen partitions. An additional design actually places a fixed nipple in the base of the feeder trough to allow for wet or dry feeding.

In group pens it is typically recommended that two rather than one drinker be installed to reduce aggression at the drinker and to assure that if one drinker becomes occluded, the other is available until the problem is detected. When two stationary drinkers are installed in a pen, they should be mounted far enough apart so that two pigs can drink simultaneously without aggressive encounters.

One consideration often discussed with swine drinker devices is flow-rate. Pigs adapt to a slow flow rate by simply increasing drinking time. But if flow rate is too restricted aggressive behaviors at the drinker can be increased and some pigs may not receive the required amount of water. On the other extreme, excessive flow rates can result in greater water waste and premature filling of manure collection pits. The following table offers general recommendations for flow rates of swine drinking devices. Flow rates are easily checked with a collection vessel and a watch that reads in seconds.

Suggested Drinker Flow Rates for Swine

Class of Swine:	Flow Rate
Early-weaned pigs	1 cup (250 cc) per minute
Starter pigs	2 cups (500 cc) per minute
Grower pigs	3 cups (750 cc) per minute
Finisher pigs	1 quart (1000 cc) per minute
Sows and boars	2 quarts (2000 cc) per minute

Suggested Reference:
Thacker, P. A. 2001. Water in Swine Nutrition. Pages 381 – 398 in Swine Nutrition 2nd edition. A. Lewis and L. Southern, Editors, CRC Press, Boca Raton, FL.

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