A guide on how to improve water quality on poultry units

Issues with water quality that are left unaddressed can have long-term negative effects on a flock, both in terms of bird welfare and the economic impact of disease and poor performance.

See also: 4 key actions to help many poultry flocks in hot weather

There are many reasons why poor water could be damaging a flock and identifying and rectifying these requires a methodical approach, says Richard Turner of St David’s Poultry Team, Exeter, Devon.

© St Davids Vets

Caution must be taken to maintain bird and operator safety, as well as ensuring maximum efficacy.
Most poultry sites have a water-sanitising system in place to clean water and remove any bacterial load entering the unit. However, systems are not always as effective as producers assume.

So what are the main causes of water-borne gut problems and what steps should be taken to ensure water is clean and safe?

Main water-borne parasites and diseases

  • Enterococcus – Can lead to septicaemia.
  • E coli – Leads to multiple diseases including colibacillosis and peritonitis with symptoms like respiratory distress, weight loss, decreased egg production.
  • Salmonella – Infections cause a range of issues on the food chain depending on the actual strain
  • Protozoa – Cause blackhead disease and coccidiosis.

Sources of infection

A lot of farms use borehole water and while there is nothing wrong with this, some areas may be contaminated with iron, manganese or other minerals.

“This might affect the gut microbiome, interfere with medication, block therapy product actions or change the efficacy of some line sanitisers,” says Mr Turner.

Units with wells may become contaminated from surface water when water tables are high.
In addition, units positioned on higher land might have wells or boreholes sunk deep into the ground, which are picking up river water, resulting in contamination.

Drought may also cause issues, as lower water levels may have a higher mineral content.

Even where producers are connected to the mains, water lines are a major source of infection as a jelly-like substance called a biofilm can develop inside the lines.

This is where different bacteria, algae and fungi form a mucopolysaccharide – or long chain sugar molecule – to hide within, or feed from, essentially creating a homestead of pathogenic bacteria.

Other sources of infection include systems where drinkers double as perches, meaning that chicks are defaecating into the cups. “This is a really big challenge to a water system,” says Mr Turner.

In older set-ups, water tanks may not be covered well enough or may be hard to clean, while old metal pipework can harbour bacteria if left uncleaned.

Also, pathogens like protozoa can be transmitted in puddle water as well as in dirty drinker cups where build-up of lime makes cleaning difficult.

Influencing factors

Temperature affects bacteria growth rates. The closer the water temperature is to a bird’s body temperature, the more likely it is to create a suitable environment for bacteria. “Water temperature below 20C is better but be wary of causing conflict with consumption rates.”

The first week of a new flock provides the ideal conditions for a biofilm to develop.

“The water flow level is low, the shed temperature is 30-31C and a lot of farmers will be using vitamin supplements or nutraceuticals, which might have a glucose carrier that encourages bacterial growth,” explains Mr Turner.

Early chick mortality problems can also result in drinker-line issues, resulting in a resident infection that can spread through the house.

Young chick systems may use recycled wood as litter, which can have a high bacteria contamination. As soon as this gets into a drinker cup, the water is infected and efforts to provide clean water are void.

Acidic water is more hostile to pathogenic bacteria so it is advisable to test and aim for a pH of 5 to 6 when supplied in conjunction with chlorine. If using organic acids the target range should be pH 3.8 to 4.2.

Using organic acids to achieve this will also promote gut health, but there is a careful balance to be found.

Testing and quality checks

Testing water is vital – costs are minimal when compared to the cost of infection, so sample water lines every quarter, with care taken to avoid cross-contamination, Mr Turner advises.

Routinely audit the lines, sample what is going into the shed prior to water treatment and sample the water after treatment to prove it is effectively killing bacteria and so you know the final quality of your water, he adds.

Cleaning and disinfection

Regulation on disinfectants is not as stringent as producers may assume – many of those on the market have not passed the EU’s Biocidal Product Regulations – so check the label before buying.

Equally, check that water sanitisers are safe for the bird to drink, and use them at the correct dose rate. Used at too high a level, these may kill both the bad bacteria in the water and the healthy bacteria in the bird’s microbiome.

The average recommended dose rate of hydrogen peroxide for it to be effective is 3% when the shed is empty, but for bird safety it would need to be as low as 1:10,000. It can be used at low rates in situ to maintain line condition while additives are being used.

Biofilms may be more difficult to target because they protect the bacteria; although a chemical may be effective against bacteria, it may not be able to penetrate the biofilm.

In broiler systems, turnaround is the major opportunity for a deep clean. “If you don’t get this right, the chances of getting on top of it during the crop are low,” warns Mr Turner.

This is where routine testing and knowing the levels of infection are vital, so that each situation is treated according to its bacterial load.

Whether to leave water in lines at turnaround can be a conundrum. Left in, the water will be stagnant and may develop a bacterial load, especially if splashback from shed cleaning causes cross contamination – something that can occur even if lines are lifted out of the way.

However, if water is removed, rubber seals can dry out and cause leakage. “Sterilise the lines before raising them, then flush them, finish cleaning the shed and chemically treat the lines again.

“Afterwards, put clean water in and make sure there’s no disinfectant left in the line.”

Cleaning and sanitisation products can be dangerous so automatic handling is advisable wherever possible, he adds.

“Having a good stock person, with clear cleaning protocols in place for water sanitisation and auditing, means the farmer can be sure that what they think is happening is actually happening.”

Water treatments

  • Ultraviolet filters – UV radiation kills bacteria but filters are often of insufficient capacity for the volume of water treated.
  • Electrolysed water – Creates hydroxyl ions, which kill bacteria and prevent the build-up of biofilm.
  • Chlorine dioxide or chlorine tablets – A cheap option to kill bacteria and prevent the build-up of biofilm, but can create an unpleasant taste.
  • Peracetic acid cleaners – Broad spectrum disinfectant used to remove limescale-based biofilms – corrosive to certain systems.
  • Hydrogen peroxide – Used to clean lines, removing biofilms and organic matter – useful to clear residue after adding vitamins, minerals or medicines to water.
  • Organic acids – Promote gut health by nourishing beneficial bacteria, sanitise water, reduce pH and break down limescale.