Water Quality Requirements for Efficient Broiler Production By Martijn Gruyters, Senior Technical Manager, Cobb-Europe


Water quality

It can be said that if the water is not good enough for us to drink then it isn’t good enough for our birds to drink. Several factors will affect the quality of water, with the source, bacteria, pH level, hardness and total dissolved solids all being important. When the water supply to a poultry house is not correctly managed it may harbor many production challenges such as bacteria, viruses, and protozoa. A poultry drinking system is a perfect environment for bacterial growth. For example, during the start of a broiler flock, high brooding temperatures cause the temperature of water within the system to rapidly increase. High temperature combined with the slow movement of water in the system (as consumption is at a low rate) creates an ideal environment for microbial growth. The temperature of water can be easily checked and monitored using a combined temperature/pH measurement device. Ideally water temperature should be below 20°C but always aim to keep it below 25°C to prevent microbial growth.

Water samples should be taken at a minimum of 2 times per year (one during summer and one during winter) and should be tested for microbial contamination and mineral content. The samples should be taken at the source and at the end of the drinker line. Make sure the water is fresh when sampled, so let it run for a few minutes before sampling. Collect the sample in a sterile container and fill it so there is no airspace. Ensure samples are correctly labeled and shipped to reach the lab within 24 hours after sampling (See our water quality guidelines in the Cobb Broiler Guide available at Cobb-vantress.com).

The concentration of free hydrogen ions (pH) has a big impact on water quality and consumption. Pure water has a pH of 7 and a change in scale of 1 unit represents a ten-fold change in the concentration of hydrogen ions in the sample. If pH levels reach above 8, water consumption will be reduced causing negative effects on feed intake and flock performance. When pH drops below 6, vaccines and medications delivered through the drinking water will be negatively impacted. If pH drops below 3, the water will be unpalatable to the bird and corrosive to the equipment. It is important to note that the pH level will impact the efficacy of sanitation.

Hardness of the water is a measure of the presence of dissolved minerals and ions. The main minerals and ions affecting the water hardness include calcium, magnesium, iron, and manganese. High levels of these minerals and ions can form lime scale or sludge in the drinking system, reduce the pipe volume, and significantly influence nipple flow rates. It may also affect medications, disinfectants and sanitizers making them less effective. Sodium based softeners can reduce the hardness of water, however, this is not recommended in poultry houses as birds are very sensitive to high levels of sodium (> 50 mg/liter) in the water.

Water sanitizing

A very common tool to sanitize water in a broiler house is chlorine. When chlorine is added to the drinking water a chemical reaction occurs with the formation of hypochlorous acid (HOCl). In general, lower pH values will produce more HOCl, therefore chlorination becomes more effective. Effective chlorination requires a pH below 7.

The oxidation-reduction potential meter (ORP-meter) is a relatively easy tool to use to test the disinfection potential of water. The ORP-meter measures in millivolts (mV). The higher the value, the better the disinfecting power of chlorine when added to the water. A low ORP-meter value indicates a heavy organic load which will reduce the biocidal efficacy of chlorine. Optimum values to potentially kill E. coli and viruses with disinfectants is 650 mV, while Salmonellae or Clostridia need 750 mV. Chlorine will not be effective at levels below 250 mV.

Drinker systems and management

Many factors (age, breed, house temperature, feed form) will influence broiler water consumption. In addition, the type of drinking equipment installed in the broiler house and how many units are available (number of birds/drinker, nipple) will impact consumption. Over the last 20 years, drinking systems for broilers have been improved. The major hygienic change was the transition from open water systems (bell drinkers) to closed systems (nipple lines). Open water systems have a higher risk for bacterial contamination since organic and foreign material have easier access to the water compared to a closed system. Moreover, a closed system makes it easier to control water temperature, minimize water spillage (drier litter), clean, and to transport medication and additives to the birds. However, closed water systems are more difficult to visually check on a daily inspection. Never assume that the water quality is good. Always test it, treat it, and flush it!

Whichever water delivery system is used, it can only be successful if managed correctly. A 360 ° nipple provides easier water access and is an absolute must for broiler and broiler breeder rearing facilities. For broilers, calculate the number of nipples (low/high flow) at a rate of 10 to 12 birds per nipple. Expect any compromise in this number to have a negative impact on water intake and subsequently feed intake and growth.


Drinker height depends on the flock age. At placement, position the nipple pin at chick eye height for easy access. After 2 to 3 hours and beyond (for broilers), reduce spillage by adjusting the water line height so that the bird’s head is at a 45-degree angle to the nipple. Incorrect drinker height can be immediately recognized by observing behavior and water consumption patterns of the birds. A nipple system with drip trays will allow visual assessment of the pressure. Wet drip trays indicate that the water pressure is too high causing water spillage. Remember, high water pressure does not translate to higher water consumption but can increase water spillage.

Nipple flow rates will be impacted by the nipple type, waterline pressure, and system cleanness. Therefore, it is important to set the nipple flow rate by adjusting the water pressure in the water line. Table 1 can be used as a reference for water flow rate based on the age of the broiler birds. However, always follow the manufacturer’s guideline.

Birds will spend less than one minute drinking. They should be able to consume the amount necessary or performance will be reduced. Water should be readily available. A bird should not have to walk more than 3 m to access water any place in the house. Incorrect waterline management will greatly impact the performance of a flock. A 20 % water intake reduction can result in a 200 g body weight reduction at 21 days. If water consumption decreases at any point during the cycle, bird health, environment and management should be re-assessed. It is important to record and chart flock water consumption by using the house water gauge (Figure 1) because it can serve as an early indicator of flock performance problems.

The main risk with closed water systems is the buildup of biofilm (Figure 2). Biofilms are slimy matrices produced by bacteria which can accumulate inside a water line. Biofilms can harbor bacteria viruses, parasites, fungi and algae and are difficult to remove. They may block nipples or cause them to leak. A strong aggressive cleaning and sanitizing program between flocks is recommended to prevent biofilms from forming. It is also recommended to flush and sanitize the water line. Flushing is only effective with a water flow of at least 2 m/s (1.5 to 2 bars). A proven product to remove a biofilm from a drinker system is hydrogen peroxide (H2O2) as it will break down the biofilm and is non-corrosive for the drinking system. Hydrogen peroxide is effective against bacteria, fungi, algae, and viruses when used at the correct concentration and contact time. It can also be used at low concentrations (final concentration in the water 0.2 % H2O2) during the production cycle to control and prevent biofilms. Always follow manufacturer’s instructions when using any chemicals.

About the author

Martijn Gruijters has 21 years of poultry industry experience, 14 of which have been at Cobb. He services the European region. Martin holds bachelor’s and master’s degrees in animal science from the University of Wageningen.

Table 1. Guidelines for water flow rate from broiler nipple drinkers

Age (days) Flow per minute (ml)
0 to 7 40
8 to 14 50
15 to 21 60
22 to 28 70
29 to 35+ 90


Figure 1. House Water Meter

Figure 2. Water line with accumulated biofilm and organic material.