Good water helps the digestion process, the transport of the nutrients in the body, the regulation of the body temperature and the elimination of waste. In this way, water has a big impact on both the health status and the production results of the birds.

The water itself can be a source of contamination when its microbiological condition is not optimal (too many germs). Moreover, its chemical characteristics (e.g. too hard, too much iron, too much calcium, etc.) can impede a good digestion or a good absorption of additives like medicines, vaccines, vitamins, etc.

The administration of these additives via the drinking water will create a polysaccharide layer in the system, known as the "bio-film", in which micro-organisms will develop and ultimately contaminate the chicks. You will not see it as it builds up inside the waterlines, but be sure it is there. Moreover, mineral deposits (esp. calcium), known as "lime" or "scale", will also build up inside your drinker lines and provide a shelter for micro-organisms. Both can block your drinkers ( reducing the water flow and adversely affecting the distribution of these additives). Check your flow rate of the last drinker and compare to the manufacturer's specifications ( ml/ min).

Dirty water supply lines, full of scale, hide all kind of micro-organisms in the bio-film. The high temperatures and the low water flow when starting day-old-chicks will create an ideal environment for an exploding development of unwanted algae and bacteria in the watering system.

Therefore, the first thing to do when cleaning a poultry house is to clean the inside of the water lines, removing the bio-film and the scale. Chlorine will not remove the bio-film, neither the scale. Moreover , it will increase the pH of the water. Finally, it will be inactivated by organic matter ( as all halogens do), especially at the end of the line, where the water flow is the lowest (after the last drinker, nipple or cup, it becomes zero) and the temperature and contamination is the highest. So, if you analyse your water micro-biologically, always take the sample at the last drinker.

So, what are the possible alternatives to chlorine? Let's first look at the clean out of drinker lines:

1. Oxidation:
   To get rid of the biofilm, a free oxygen molecule is required to "burn" it away. This O2 can be released from different sources :
   • ozone ( O3) installations proved to be expensive for a poultry house.
   • Chlorine dioxide needs to be activated on the farm by mixing because it's not stable. We will focus only on Ready To Use products that are easy to apply ( and avoid the "human error" ) and do not need expensive activators.
   • H2O2 or hydrogen peroxide will remove the biofilm. The secret of H2O2 is how to stabilise it ! (Straight H2O2 is used as "fuel" for rockets; it's a very explosive product and hence dangerous !). One way to stabilise is to add silver nitrate, however this is a heavy metal and not always liked. In all cases, if you check on the shelf life by comparing manufacturing date with expiration date, you'll have an understanding about stability and shelf life.
   
   
2. Acidification:
   Acids will dissolve the scale ( mainly Calcium based) that can equally block the drinkers. However, they will not dissolve the biofilm completely.
   
   
3. Oxidisers combined with organic acids:
   Stabilised hydrogen peroxide formulated with organic acids ( that will form PER-acids like Per Acetic Acid) will dissolve both the biofilm and the scale build up.

It is very important to flush the lines abundantly to eliminate all residues after a certain contact time. Only then, you will start with clean and sanitised lines. This is an absolute preliminary condition to further optimise the water quality, with the goal to improve your production result.

A further water treatment during the lifetime of the chickens can avoid a new build-up of bio-film and scale, but especially sanitise the water ( E. coli and Salmonella spp. are the major bugs to monitor. They require an alkaline environment, ideally above 8 ). When sanitised or acidified water reaches the crop (that has a slightly acid to neutral pH : 4.5 - 6 ) , this means a better start. The pH in the gizzard is acid ( 2.2 - 4.8) and will reduce the bugs, however the contact time is very reduced because of the fast throughput. In the intestines, the pH is again geared towards neutral ( 5.7 - 6.9) , so they'll thrive again.

Chlorine will slightly decontaminate the water ( but less at the end of the line) but it does not bind the minerals ( like Calcium) and it makes the water more alkaline. Chlorine dissolves in water to form hypochlorous acid (HOCL), the free chlorine that is considered a sanitiser and hypochlorite ion ( OCl-) that is not considered a sanitiser (it needs 30 minutes contact time) plus H+ . But this ratio is entirely pH dependent : at low pH values, it will release mainly hypochlorous acid (HOCL) (100 % at pH 4 and lower). At pH 7 , this substance reduces to 75 % and at pH 8 it reduces to 22% only, the rest is the OCL-. Chlorine can never be mixed with acids because this would produce chlorine gas, that is very toxic. So, chlorine is not the ideal water treatment product after all.

Again, the same options can be used :

1. Oxidation : stabilised H2O2 ( ideally free of heavy metals, so there are no residues in the meat nor the eggs ) will kill a certain amount of (entero) bacteria.
   
   

2. Acidification through organic acids : a lower pH will create an environment that is less favourable for entero bacteria but that enhances the digestion. The main reasons to use are: preservation of the feed because of their pH lowering effect and reduction of pathogenic microbes in the crop and stomach (Salmonella, E.coli, etc.). This inhibits the development of pathogenic microbes and improves the digestion of nutrients. Eventually, it may even improve the taste of the feed ( water / feed mixture) . The results of above mentioned application are better performances.
   
   

3. A combination of acids and peroxides.

Experience has proven that the sanitised and acidified drinking water does not only reduce the level of pathogens in the water but it also improves the digestion of the feed and the production results. This improved digestion is obtained through a slower passage of the feed/water mixture through the intestinal tract, a better absorption of the necessary nutrients and less diarrhoea. This means better FCR's, better weight gains, lower ammonia levels in the house, better litter conditions , less foot-path problems, etc. In layers and breeders, it improves eggshell-strength and egg cleanliness. In one word: better profits !

The "take home message" is that modern drinking water treatment often gives the highest returns on investment in poultry production. It can make a serious difference !

Source: CID LINES - June 2006