Nuscience
Booiebos 5 ● B-9031 Gent (Drongen)
T +32 (0)9 280 29 00 ● F +32 (0)9 282 00 27
E [email protected] ● www.nusciencegroup.com
Newsletter – January 2013
Good water quality is basic for an optimal pig performance (Part 1)
Water is often a forgotten “raw material” in pig feeding. It can no longer be taken for granted because
access to good quality water is becoming increasingly limited and expensive. Water is a key input for
profitable pork production. It must be available at all times and it must be of good quality. Low-quality
water can lie at the basis of a wide range of problems such as stomach and intestinal disorders, skin and
liver problems, diarrhea, bladder inflammations, etc.
Pigs drink more than twice as much as they eat. At weaning, the water / feed ratio is about 4/1. Pigs obtain
water from three sources: water contained in the feed, metabolic water and water consumed by drinking.
They need sufficient quantities of water to maintain optimal production levels. Water is the single largest
constituent of the body, making up to 82% of a young pig’s bodyweight and 55% of a pig at slaughter
weight. It’s also a major component of the pig’s secretions, e.g. milk and saliva. Pigs also require water for
various important body functions such as body temperature regulation, nutrient digestion and absorption,
elimination of waste products of digestion and metabolism. The amount of water consumed by pigs depends
on many factors such as quality of the water provided, diet composition, physiological status of the animal,
environmental conditions, social factors, design and placement of the water system.
Biofilms are a major problem in drinking systems. They form a constant source of microbiological
contamination and cause blocked drinking nipples. This decreases the availability of water often drastically.
Biofilms are formed in the pipelines when microbial cells attach to the pipe surface and multiply to form a
film or slime layer. This is often accelerated when vitamins and medications are administered via the water
line, because their sugar based carriers become ideal substrates for microbes to grow. Removing biofilms in
pipelines is not evident. Regularly cleaning and sanitizing the drinking water is one method to prevent
contamination, but has its limitations. Another recommendation is to remove the biofilm by increasing the
pressure in the water line. But in many cases the mineral deposit in the biofilm remains after flushing,
leaving a shelter for micro-organisms.
A regular monitoring of the drinking water quality at least once a year is advised. The quality of drinking is
assessed on the basis of its organoleptic properties, the chemical analysis and a bacteriological
examination. The desired organoleptic characteristics of water are clear, colorless and fresh flavor. In this
first mailing we focus on the chemical quality of water. Next month we’ll look also into the microbiological
analysis and means to improve the water quality.
Chemical elements dissolved in water have a significant influence on the quality of water for swine
depending on their concentration. The values in the analysis can be compared to the reference values
determined per country/region (see table 1).
1. Water pH:
A water pH ranging from 6.5 to 8.5 is considered optimal for pigs. A pH less than 6.5 is undesirable
as it may corrode and dissolve metals from the plumbing and cause precipitation of medication
delivered via water. On the other hand a water pH higher than 8.5 gives the water a slippery feeling
and leaves scaly deposits.
2. Chloride:
Chloride levels in water above 250 - 500 ppm can cause a brackish taste which may result in low
water intake.
3. Sulfates:
Sulfates are especially in spring water a problem and generally indicate a too strong leaching of
manure to the deeper groundwater. Sulfates are laxative agents and can cause diarrhea,
particularly in piglets, at high levels.
Nuscience
Booiebos 5 ● B-9031 Gent (Drongen)
T +32 (0)9 280 29 00 ● F +32 (0)9 282 00 27
E [email protected] ● www.nusciencegroup.com
Newsletter – January 2013
4. Iron:
Iron can promote growth of certain bacteria and result in precipitation of iron compounds. Although
there is no health risk, iron concentrations of 2 to 3 ppm can block water flow from water nipples.
At a concentration of 5 ppm or greater, oxytetracycline added to the water can be inactivated. Iron
affects the palatability of water so that the water intake will decrease. Water refusal or low water
intake may occur at levels of 10 ppm or greater.
5. Nitrates and Nitrites:
Pigs are relatively tolerant to nitrates and nitrites. Contamination of groundwater with nitrates and
nitrites mainly occurs through leaching from the soil or through surface water run-off that has been
exposed to material with high nitrogen levels, e.g. animal wastes, nitrogen fertilizers, decaying
organic matter, silage juices, soils high in nitrogen-fixing, etc. High level of nitrates or nitrites in the
water may be indicative of bacterial contamination. These nitrates can then be converted into the
more toxic nitrites, which can bind to hemoglobin in the blood and impair the oxygen carrying
capacity of blood. A level of 300 ppm of nitrate may be sufficient to produce enough nitrite to cause
toxicity in swine. A level of 10 ppm of nitrite is of concern for swine. Symptoms of nitrate poisoning
include high respiration rate, increased incidence of diarrhea, reduced feed intake, poor growth,
increased abortions among sows and reduced vitamin A utilization.
Table 1: Water quality standards (ppm)
Belgian Standards
Dutch standards
Canadian
Standards
EPA Standards
(Human)
Maximum
Maximum
Maximum
6,5-8
5-8,5 (good)
.
6.5 - 8.5
Item
pH
1
Ammonia (mg/l)
≤ 2 mg/l NH4
2
.
.
Nitrite (as N) (mg/l )
< 0.5 mg/l NO4
1
10
1
Nitrate (mg/l)
≤100 mg/l NO3
200
100
10
Chloride(mg Cl/l)
≤ 1000 mg/l
1000
.
250
Salt (via NA)
< 2,000 mg/l
.
.
Iron(mg/l Fe)
2,5
10
.
0.3
1
2
.
0.05
Sulfate (mg SO4/l)
250
250
1,000
500
Calcium (mg/l Ca)
≤ 270 mg/l
1,000
.
.
3,000
500
Manganese (mg/l Mn)
TDS (Total dissolved solids)
1
High levels of ammonia indicate bacterial contamination (manure), which would make water unsuitable
Water hardness is also important and shouldn’t be forgotten in the evaluation of water quality. The
hardness of water is mainly caused by the presence of calcium and magnesium salts. The hardness of water
is internationally usually expressed in French degrees (° F) or German degrees (Number of D ° = number x
0.56 ° F). A total hardness of the water of average 15 ° F (8.4 ° D) is ideal. Too soft water (below 5 ° F)
may damage the pipe but has no negative effect on the performance of the pig. Hard water (> 30 ° F)
combined with a pH> 7 can cause problems due to calcium deposits in the water. In addition, certain drugs
such as oxytetracycline are inactivated by high calcium, magnesium and iron concentrations. In hard water
also occurs much easier mucus after medication.
Macroscopic deviations of the chemical composition of the water by excess iron, abnormal pH or
contamination can lead to a bad taste. This could imply that animals lack drinking which also will reduce
feed intake, the growth will slow, the milk yield will decrease, urinary tract infections may occur and in
severe cases it can even lead to salt poisoning due to low water absorption.