Important Factors in Water Quality to Improve Broiler Performance
By Edgar O. Oviedo, Broiler Extension Specialist, North Carolina State University - Water quality is partially responsible for variations in broiler performance among growers within the same company that receive the same feed.Other factors include housing type, equipment, and general management. Water is the most critical nutrient to guarantee the best broiler performance. The quality of the water offered to broilers depends on several physical, chemical and microbiological parameters. Bacteria, molds, minerals and water additives interact in the water source, and within the pipelines and drinkers. These interactions complicate the management necessary to guarantee the best water characteristics for optimum broiler performance.
Water quality frequently changes from season to season in each location or area depending on the source. In North Carolina, water obtained from wells generally contains high levels of minerals leading to high water alkalinity and hardness. Several water samples obtained across the state from broiler farms experiencing flock performance problems additionally contained high levels of sodium, potassium and iron. These broiler performance problems were partially solved by installing softeners and specific filters for these minerals.
It is advisable to monitor water composition every six months and not only when the producer experiences poor flock performance. Samples for analyses should be collected at the point of water supply, before any treatment or additive is applied, after treatment or medications, and at the end of the pipeline. This sequential sampling helps to determine the dynamics caused by the current water management practices. Water quality changes inside poultry house due to the warmer environment that facilitates the rapid replication of microorganisms.
Sanitation and acidification are the practices that most growers implement to improve water quality for their broilers. It is important to understand that these are two different approaches that work together to improve water quality; however, one does not replace the other. Acidifiers alone cannot replace sanitizers that effectively reduce microbial loads of heavily contaminated water sources. To obtain an effective sanitation with chlorine requires that the water pH be between 6.0 and 7.0. Consequently, acidifiers should be applied to water with pH readings higher than 7.5, which is also associated with high alkalinity.
The acid and chlorine should never be mixed together to create stock solutions, since these chemicals react and release dangerous gases. An inline pump with dual injectors can be used to add the acidifier stock solutions prior to the addition of the chlorine solution. Chlorine is not the only available sanitizer. Ozone, chlorine dioxide, hydrogen peroxide and iodine are also used in poultry production with excellent results.
Type and concentrations of disinfectants and acidifiers need to be modified according to the initial microbial load, mineral content and buffer capacity of the water to be treated. One method to evaluate a good sanitizer is using the oxidation-reduction potential (ORP). The ORP parameter measures the capacity of a sanitizer to be a strong oxidizer for destroying microorganisms or for reacting with some harmful minerals such as iron and manganese. ORP meters can be used to identify the appropriate amount of disinfectant to use for a specific water source. An ORP value in the range of 650 millivolts or greater indicates good quality water that can be effectively sanitized by 0.2 to 0.4 ppm free chlorine. Lower values close to 250 millivolts indicate heavy organic loads that will not be properly disinfected by chlorine. Excellent live broiler performance has been observed in farms that have water with ORP values close to 750 millivolts. Measuring ORP is better than using chlorine pool test kits. These kits do not distinguish between free and bound chlorine. This is important in water with high organic material content.
Water sanitation starts with a regular pipeline cleaning program to reduce the natural build-up of minerals, algae, molds, viruses and bacteria that are capable of forming bio-films. Daily water sanitation may not work when strong bio-films are established in the water lines. Citric acid, sodium hypochlorite, and quaternary ammonium compounds are some of the products used to clean water lines. Water lines can also be effectively cleaned by adding a 50% solution of hydrogen peroxide to the medicators to obtain a 1% solution in the pipeline and allowed to soak overnight. Independent of the product used to destroy the biofilm, it is important to completely flush out the dissolved materials. This material contains high levels of minerals, toxins produced by dead bacteria, algae, and free microorganisms that can be even more harmful for the new flock.
Acidifiers are used to keep water pH to less than 7.0 and help to reduce bacteria proliferation. It is common that acidifiers are added to drinking water of broilers for short intervals of one to three days at a time. However, in farms where the water pH is higher than 8.0, those days without pH control can negatively affect the efficacy of water sanitation. It is true that chickens can rapidly adapt to acid water (pH 3, 4, or 5), but constant drastic changes may affect their patterns of water and feed consumption and lead to sub-clinical intestinal problems.
It has been observed that lowering pH to less than 5.0 does not provide significant improvements in broiler performance. Overuse of organic acids such as citric and acetic acids can lead to reductions in water and feed consumption and lead to a depression in growth rate. This detrimental effect of excess acid is due to the strong taste that acids can give to water. Due to the natural buffering capacity of water and the interactions with minerals, it is recommended that producers monitor the pH of drinking water when using acidifiers at the manufacturer’s recommended levels.
Water quality management is very important to guarantee broiler performance. Constant monitoring is required and not only when problems are observed. It is recommended that water samples be collected quarterly and for a very reasonable cost can be sent to the NC Department of Agriculture Laboratories for analyses. The information gained from these analyses including your pH, ORP and chlorine level readings can be used to determine the best management practices required for your specific water conditions.
Summer 2006