Interpreting Water Results

By Dr. Susan Watkins

Interpreting Your Microbial Analysis

This information sheet is to help you to interpret the results of your recent microbial analysis of poultry drinking water and/or well water.  It consists of excerpts from the paper “Water Quality and Sanitation” by Dr. Susan Watkins from the University of Arkansas.  If you would like the paper in its entirety, please contact us at (479) 575-8428.

Bacteria TEst

The established guidelines for water quality for poultry are outlined in Table 1. Note that CFU/ml means colony-forming units of bacteria/milliliter of water, and mg/l is also the same as parts per million or ppm. The microbial or bacterial test results you receive from this lab are TPC or Total Plate Count of aerobic (oxygen loving) bacteria as measured by CFU/ml.  These results do not indicate whether the bacteria present is harmful or harmless but what it can tell you is if the system is dirty and therefore at risk for the presence of harmful bacteria.  If the total plate count or TPC level is 1000 CFU/ml or less then the water supply is considered acceptable.  However, it is very reasonable to have water tests show 0 CFU/ml even from the end of the drinker line.  The closer your water sample results are to 0 CFU/ml the better your water supply is for the modern commercial chicken or turkey.  Should the test results be greater than 10,000 CFU/ml, it is strongly recommended that the water system be thoroughly cleaned between flocks with an approved cleaner and then a daily water sanitation program implemented.  Chlorine is the cheapest water sanitizer available and works well but other products such as chlorine dioxide and hydrogen peroxide are also available and used successfully.  Target levels of chlorine are 3-5 ppm.  Target levels of chlorine dioxide are 0.8 ppm and target levels of hydrogen peroxide are 25-50 ppm in the drinking water.  

If your water test is performed by the Department of Health, the results will be total coliforms.  Coliforms are a good indicator organism that lets us know if a water supply has been contaminated by livestock (runoff from concentrated animal production areas) or human waste (failed septic system).  Should your water supply contain more than 50 CFU/ml coliforms it is definitely a good idea to treat the water supply possibly with shock chorination.  In addition, look for possible sources of contamination and correct the problem to prevent recontamination.   Never assume that water remains good through poultry house water systems.  When in doubt, test the water at the source and at the end of the line.  Results from previous water tests (Table 2) show just how dramatically water quality can change even over the course of a few hundred feet.

Use the following guidelines to determine when water supplies should be tested:

•         Noticeable change in color, odor or taste

•         Flooding has occurred near well

•         Person or animal becomes sick from waterborne disease

•         Maintenance on water supply system

•         Persistent poor performance

•         Loss of pressure in water system

MINERAL TESTS

There is no such thing as pure water in drinking water supplies.  All drinking water has some amount of minerals dissolved in it.  The majority of the time, these dissolved minerals are well within acceptable ranges but unfortunately  there are many cases of contaminants that are not within desired levels which results in the following issues:

1. Poor performance
2. Equipment failure or damage
3. Presence of harmful bacteria or fungal slime (some minerals can act as a food supply for these).

 One way to understand how much is a ppm is consider one gallon of sugar dissolved into a million gallons of water. That would give 1 ppm of sugar. Although parts per million (ppm) of anything seems quite small, remember, the birds already receive a balanced diet and if they are also receiving high levels of such nutrients as salt in the water, in the form of sodium and chloride ions, then over time the birds may exhibit poor performance because they just have more than their systems can handle. In addition, water contaminants can also impact how nipple drinkers work. Even a fine buildup of mineral residue on seals or rims could be all that is necessary to limit water flow and thus result in less than adequate consumption for optimum bird growth and feed conversion.

Conclusion

In conclusion, water is the most essential nutrient birds receive, yet the quality of bird drinking water is often taken for granted. Providing flocks with a clean, wholesome supply can make a difference in performance. Should water be a suspect for flock problems, make arrangements to have water tested for total bacteria numbers as well as for mineral content. While total aerobic plate count won’t tell exactly what is in the water, it is an indicator of excessive levels of bacteria that should be addressed. By promoting a regular water sanitation program on farm, producers can prevent environments in water systems that could lead to poor bird performance.