How to improve water hygiene in poultry production

In modern poultry farming, productivity can be influenced by several factors such as ventilation, temperature and humidity control, supply of oxygen, lighting program in reproductive cycle management, vaccination, and prophylaxis or metaphylaxis intervention. Although these are all important, the more important and critical factors are chick, feed and water quality, because these three components are the major resources required to produce meat and eggs, which are the final products of poultry production.

To produce high quality chicks, the incubation process—hatchery management, hygiene and transportation of eggs and chicks, needs to be carefully checked. To improve feed quality, a good selection of ingredients and formulation of diets, proper feed processing and feed hygiene program are needed.

Water is an essential nutrient, but sometimes overlooked because it is an inexpensive utility compared with other resources, and is readily available. However, water is a critical biological ingredient that contributes to several aspects of the animal metabolism for growth and reproduction. Water is involved in physiological functions including digestion and absorption processes (softens feed in the crop, passage and transport of feed through the gastrointestinal tract, enzymatic processes), thermoregulation (cools down body temperature), tissue hydration (component of blood and body tissues, lubricates joints among others), and elimination of waste (feces, urine). If we consider that approximately 70% of chick´s body weight (up to 85% at hatch) and 74% of eggs’ weight is water, any reduction in water intake will impact the lifetime performance or even viability of the chicks. Chickens will drink about twice as much water as the uptake of solid food, or even higher during hot conditions, with an increase in water intake by 6-7% for each degree above 21 °C, according to the NRC 1994. Therefore, supplying good quality drinking water is essential for ensuring high performance.

Water requirements for poultry production

Several factors might affect water consumption:

  • The bird’s physical factors: Age, health, disease challenge or thermoregulation.
  • Water quality factors: Hardness, nitrate levels, total dissolved solids, and bacterial contamination
  • Feed related factors: Type, composition, amount and quality
  • Environment related factors: Housing temperature, water temperature and water pressure, drinking system or drinker height

In poultry production, water requirements can be considered from two points of view. Firstly, looking at the requirement of the animal, water should be clean, uncontaminated (free of bacterial contamination or other contaminants), non-toxic with appropriate levels of minerals and organic matter, and freely available to birds at all times. Secondly, from the producers’ point, water should be supplied at a low cost without the need for unnecessary installation costs.

The consumption of water is not easily affected by taste and smell, but it is easily changed by climate, temperature and water temperature. Birds prefer water temperature between 10-14 °C. However, a more practical recommendation for water temperature is 15-21 °C, as water intake might increase with temperature between 21-27 °C, and reduced when temperature hits higher than 27 °C. If it is not possible to ensure water temperature maintains at a maximum temperature of 30 °C in hot climates, insulation of water pipes should be considered. Salinity is not a common issue because poultry are tolerant to up to 250 ppm of salt in water. However, if high levels of sodium (Na) in water is present, it is necessary to consider this from a diet formulation perspective, or unevenness and poor growth rate might occur. It is important to consider that excess levels of Na, potassium (K) and chlorine (Cl) in diets will increase water intake and the occurrence of wetter droppings. In terms of other minerals, moderate levels of iron (Fe) (2.5-10 mg/L) and high levels of manganese (Mn) (>1 mg/L) can result in precipitation in the pipe lines and clogging of the water system, while high iron (>10 mg/L) can result in a bad odor and taste in water. Magnesium (Mg) levels above 125 mg/L might give a laxative effect with intestinal irritation and consequently diarrhea. Healthy birds can drink water with sulfate (SO42-) without problem, if levels of Na or Mg are lower than 50 mg/L. Otherwise, a laxative effect could be observed. High sulfate levels (>230 mg/L) can produce very toxic sulphide (S2-) when combined with oxygen (O2) and some bacteria. These problems can be determined by examination with the naked eye. For example, water with high iron content shows a red color, water with manganese shows a black color, and water with high levels of sulfur (S) produces a rotten egg smell with black color.

Hardness, which is primarily measured by calcium carbonate (CaCo3) content, is another problem for water quality in poultry production. Although hardness itself is not a serious issue because poultry species are tolerant up to 1000 ppm (56 °dH), mineral deposits in water lines is a concern for water hygiene. If the water has high hardness (>20 °D), the formation of mineral deposits increases, which creates a backbone for microorganisms to collect and attach, thereby increasing the probability of biofilm formation. Water with high hardness can interfere with effectiveness of soap and many disinfectants and medications administered via water. It is hard to mix certain medicines (antibiotics like florfenicol, anticoccidials like toltrazuril, and insectifuge) in water with high hardness.

Routine laboratory examination for water quality is highly recommended. Reference for water quality is described in Table 1, and the reference value can be varied according to region or water source.

Table 1. Reference value for water quality

The quality of water is not only important for digestion and production, but is also critical to keep birds free from disease. Water in the poultry house usually moves slowly and is warmed by external temperature, especially during the brooding period. It also contains many nutrients because sugar and natural contaminants are always supplied during medication and vaccination practices. High temperatures and sufficient food are excellent conditions for bacterial growth. Water systems harbor high levels of bacteria and these bacteria can transfer into the intestinal system of birds through the water. Bacteria are not the only pathogens in water, but other pathogens like mycoplasma, virus and protozoa and algae can also live in water and water systems. These microorganisms can transfer to birds through water (water borne pathogens). Table 2 lists some of the water borne pathogens.

Table 2. List of water borne pathogens (non-exhaustive)





Avian influenza virus




Newcastle Disease Virus

E. coli Histomonas  

Marek’s Disease Virus


Infectious Bursal Disease Virus


Water sanitation program

Although several options are available for water sanitation in poultry production, cleaning with an effective cleaner during the downtime period is a precondition to improve the water system hygiene. The proper concentration of cleaner left in for a sufficient time is the key to success. 1.5% hydrogen peroxide and 1% organic acid for 24 hours is usually recommended for this cleaning process. After the cleaning process chemical agents should be flushed before placement of birds. Multiple flushing without a chemical agent during the production cycle is also recommended for long live birds to maintain the lines clean.

Chlorination and acidification are tools to ensure clean water during the production period. Chlorination is a very cheap but effective way to decrease the bacterial population in water. Mostly 4-6% of sodium hypochlorite with 3-5 ppm is used for chlorination. The efficacy of chlorination depends on pH, water temperature and dirtiness of water. Among these factors, the most influential factor is pH because chlorine produces more hypochloric acid (which is 200 times more effective as a sanitizer than another metabolite, hypochlorous ion) in acidic conditions. More than 90% of chlorine can produce hypochloric acid in water with a pH below 6. (Table 3)

Table 3. Impact of pH on the ratio of hypochloric acid to hypochlorous ion


% of Hypochloric acid

% of Hypochlorous ion





21 79


48 52


72 28


90 10


96 4


100 0

Hydrogen peroxide was used in poultry production in the past, but it is not commonly used alone in poultry production in Asia due to its flammable nature and bad taste.

After going through sanitation programs to clean and disinfect drinking water systems, the additional use of organic acid-based products might help to maintain a good quality water. The dissociation of organic acids have a pH-reducing effect which provides a pH in water low enough to reduce the proliferation of bacteria. On the other hand, organic acids in undissociated form have a direct antimicrobial effect against Gram-negative bacteria. This is because in its undissociated form, organic acids are able to enter the cell of the bacteria and dissociate inside the bacteria, affecting its viability by reducing the cytoplasmic pH and by anion specific effect on bacteria metabolism. In addition to these benefits, organic acids can also have effects on the performance and on the gut health of the animals.

Maintaining optimal water quality by reducing bacterial load in drinking water

Biotronic® Top liquid product is an enhanced organic acid-based product, which contains a combination of organic acids and the Permeabilizing Complex™ mixture. This product helps to reduce the contamination of drinking water with Gram-negative bacteria like E. coli, Salmonella among others.

Figure 1 shows an in vitro study with tap water artificially contaminated with E. coli (105 CFU/mL) further divided in two groups with three replicates each, with one group not receiving any treatment (Control Water), and the other with addition of Biotronic® Top liquid to reach pH 4.0 in the water (Water with Biotronic®). The concentration of E. coli (bars) and pH value (lines) was evaluated at different time points for 48 hours. The results show a reduction of 1.54 log at 4 hours and complete reduction of E. coli in the contaminated water after seven hours when using the enhanced organic acid product.

Figure 1. Effects of Biotronic® Top liquid on tap drinking water contaminated with E. coli.
Figure 1. Effects of Biotronic® Top liquid on tap drinking water contaminated with E. coli.

The efficacy of Biotronic® Top liquid via drinking water on the reduction of E. coli challenge in poultry

This study evaluates the efficacy of Biotronic® Top liquid on the reduction of E. coli in a challenge model compared with broad spectrum antibiotic. In this trial, three groups were assigned: a control group without any medication via water or feed, a positive control group receiving 0.5 mL of enrofloxacin per liter of water, and a trial group receiving 1.25 mL of Biotronic® Top liquid per liter of water. At 10 days old, all birds were orally challenged with E. coli O78 (1.38x108 CFU/mL), and 10 birds from each group were sacrificed at 10 days and 20 days post challenge for bacterial count and lesion scoring.

Figure 2: E. coli count (log CFU/g) in intestinal tract
Figure 2: E. coli count (log CFU/g) in intestinal tract
Figure 3: E. coli count (log CFU/g) in the liver
Figure 3: E. coli count (log CFU/g) in the liver
Figure 4: Lesion score for colibacillosis
Figure 4: Lesion score for colibacillosis


The supplementation of Biotronic® Top liquid in water helped to reduce the challenge with E. coli reducing the number of E. coli counts in the intestinal tract and liver. Lesion score at 10 days and 20 days post challenge also showed that Biotronic® Top liquid could protect the birds from an E. coli challenge.

The studies (in vitro and in vivo) showed here support the use of Biotronic® Top liquid as an effective tool to prevent the risk of Gram-negative bacterial infection via water in poultry production.

References available upon request
This article originally appeared in Asian Poultry.

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