Every producer knows the importance of providing their birds with a constant supply of good quality water. However, it is an aspect of management that can sometimes be neglected, according to specialist poultry vet Keith Warner.


The assessment of water quality can be broadly divided into two categories: Bacteriological count and mineral content, he explains.

Bacteriological count

Water contaminated with bacteria can adversely affect growth rates, and cause a range of symptoms, including death, says Mr Warner. A full bacterial profile is recommended, to ascertain levels of E coli, staphylococcus, streptococcus and enterococcus – the main types of harmful bacteria that affect water quality.

Unless producers adopt a strict clean water regime, there is a high risk that bacteria will multiply to a level which will affect the birds’ performance, says Mr Warner, of the Minster Veterinary Practice, which has offices in York, Nottingham and Herefordshire.

Bacteria levels are normally expressed in terms of numbers per millilitre of water. A clean system would contain fewer than 100, so tests showing higher levels will require further investigation.

Mineral content

Mineral content must also be considered, when assessing water quality. An imbalance of salts, minerals or heavy metals can cause a variety of problems.

Heavy metals are particularly damaging at high levels, and will limit the uptake of antibiotics. They will also reduce the efficacy of standard vaccines, as well as rendering live vaccines useless. A high salt content will lead to excessive drinking, resulting in wet litter that will further threaten the birds’ health.

Boreholes

It is unusual for mineral problems to develop on farms with mains water, says Mr Warner, but borehole water can be less reliable. Any producer whose flock is experiencing health problems or unusually slow growth rates is advised to investigate borehole water contamination at an early stage, he adds. In cases where problems cannot be easily corrected, it may be worth contacting your borehole supplier.

Palatability

The palatability of water is variable. Contamination can put birds off drinking, which will depress appetite and reduce productivity. Temperature can also influence bird behaviour; water should always be offered at a maximum 20C, and stored in an insulated tank, to prevent freezing in winter.

Sampling and testing

Bacterial contamination usually occurs within the housing, advises Mr Warner. He suggests eliminating all other points of potential water contamination, before testing water at source. Ideally, water should be tested prior to each bird placement, during mid-crop and following bird evacuation. Drinking water bacterial quality evaluation will usually cost around £15 a test.

A full mineral test should include:

pH, sodium, potassium, calcium, chloride, iron, manganese, magnesium, nitrites, nitrates, copper, zinc, lead

Sampling protocol

To avoid false results, use a sterile container for sample collection. Open the container in clean surroundings, and avoid touching any area which will come into direct contact with the stored liquid. Take a minimum of five water samples from each house, including the header tank, incoming source, drinker lines and drinker point.

Did you know?

A batch of 1000 birds in full production will drink an average 200 litres (200ml per bird) of water per day.

Drinking water quality guidelines

Characteristic or contaminant

Average (mg/ml)

Maximum (mg/ml)

Remarks

 

 

 

Bacteria

 

 

 

Total Bacteria

Not available

100

0 is desirable

Coliform Bacteria

0

50

0 is desirable

 

 

 

 

Nitrogen Compounds

 

 

 

Nitrate

1

1

3 – 20 may affect performance

Nitrate

0.4

n/a

 

 

 

 

Acidity and Hardness

 

 

 

pH

6.8 – 7.5

See remarks

A pH of less than 6.0 is not desirable. Levels below 6.3 may affect performance.

Total Hardness

60 – 180

See remarks

Hardness levels less than 60 are unusually soft, those above 180, very hard.

 

 

 

Naturally Occurring Chemicals

 

 

 

Calcium

60

75

 

Chloride

14

250

Levels as low as 14 may be detrimental if sodium levels are higher than 50.

Copper

0.002

0.6

Higher levels result in a bitter flavour.

Iron

0.2

0.3

Higher levels produce a bad odour and taste.

Lead

n/a

0.02

Higher levels are toxic.

Magnesium

14

125

Higher levels have a laxative effect. Levels greater than 50 may affect performance if sulphate levels are high.

Sodium

32

200

Levels above 50 may affect performance if the sulphate or chloride levels are high.

Sulphate

125

250

Higher levels have a laxative effect. Levels above 50 may affect performance if magnesium and chloride levels are high.

Zinc

n/a

1.50

Higher levels are toxic.