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CHICK-NEWS: How should a poultry watering system be evaluated?
Robert: “The suitability of systems should be evaluated based on what proportion of the water that goes through a meter in a poultry house is actually ingested, compared to the quantity that is not. The basic concept is to distinguish between water usage and actual consumption by the bird. Usage is essentially the quantity of water that passes through the water supply pipe divided by the number of birds in a flock. Consumption is what the bird actually ingests. The difference between water usage and consumption is the quantity spilled.
Unfortunately, nipple type drinkers are often evaluated and operated based on flow rate. A far better way to evaluate a watering system and a drinker is to evaluate and correlate bird performance with the moisture level of litter. Great broiler results including weight, conversion, livability and acceptable foot pad appearance means that the flock not only ingested adequate water but also had a favorable production environment. They were in fact raised on dry friable litter with little or no ammonia release. Comparing all the various brands and models of nipple type drinkers available today simply applying a flow rate formula may result in either too little water discharge or too much - either of which will have a negative effect on broiler performance.
CHICK-NEWS: What is the difference between static flow rate and dynamic discharge?
Robert: “Static flow rate is the quantity of water released from the nipple drinker when the trigger pin is lifted vertically and held in the open position for a specific amount of time, usually for one minute with flow rate commonly expressed as ‘milliliters per minute’. Dynamic discharge is the quantity of water discharged from the drinker during the time that the bird is pecking intermittently at the trigger pin during the natural pattern of drinking “
CHICK-NEWS: Can dynamic discharge be measured?
Robert: “Unfortunately dynamic discharge cannot be directly measured. What we do know is that there is no direct correlation between the static flow rate when the trigger is lifted vertically compared to natural discharge with side-to-side dynamic activation. To demonstrate this Ziggity constructed a mechanical test bed that closely mimics the drinking pattern of a chicken pecking intermittently at a nipple trigger. Two available nipple drinker brands were selected for evaluation using the same water column pressure. Brand A had a static flow rate of 35 ml/min when the trigger was raised vertically while Brand B delivered 73 ml/min. yielding 109 percent more water than Brand A. When these two nipple drinkers were tested on the intermittent activation test bed Brand A discharged 12.2 ml/min of water while Brand B with the high static discharge rate released only 5.5 ml/min. Effectively Brand A discharged 120% more water than Brand B. The takeaway is that a higher static flow does not automatically result in a higher dynamic discharge rate. While this does not tell how much water a chicken ingests when drinking it does question the validity of static flow rates in managing water column pressure or selecting a brand of nipple drinker to install or retrofit”.
CHICK-NEWS: How do you relate the concept of dynamic discharge to management of water systems?
Robert: “Dynamic discharge or the amount of water that is released from the drinker when pecked by a bird is dependent on column pressure. Higher column pressure discharges more water into the bird’s beak than set at a lower column pressure. Selecting an appropriate column pressure is a function of beak capacity. Small chicks require a low column pressure so the drinker does not discharge more water than can be retained in the beak before swallowing. Any discharge of water above the capacity of the beak gravitates to the litter. The greater the volume of oversupply the higher the water content of litter. Growers are advised therefore to ‘read’ the litter directly under the drinker lines and adjust column pressure accordingly. Dusty dry litter under the drinker lines could mean column pressure should be raised and wet litter means it should be lowered. The ideal column pressure setting would provide dry friable litter with just a hint of moisture.”
CHICK-NEWS: What are the effects of wet litter?
Robert: “We are aware that wet litter can contribute to a number of health and quality problems. These include pododermititis that is especially costly with heavy birds. Feet that command a unit value of approximately $1,500 per ton when exported to China are downgraded or rejected if foot pads are damaged. Auditors consistently lower welfare scores if flocks demonstrate pododermititis either in the house or at the plant. Dermatitis is a concurrent problem occurring with pododermititis. Birds entering plants with fecal and litter-stained feathers increase the microbiological load entering scald tanks. Wet litter also contributes to breast blisters that result in downgrades. Wet litter is also associated with severity of coccidiosis and various forms of enteritis including clostridial necrotic enteritis.”
CHICK-NEWS: Are there any other problems related to wet litter?
Robert: “Wet litter allows bacteria to generate ammonia that represents a manageable welfare criterion. Ammonia irritates the conjunctiva and corneas of eyes, degrading performance. Ammonia levels above 50 ppm for extended periods also damage the delicate lining of the respiratory tract, predisposing flocks to airsacculitis if respiratory viruses and pathogenic E. coli are present.”
CHICK-NEWS: Don’t manufacturers sell nipple type drinkers with drip (catch) cups to prevent wet litter?
Robert: “That may be the intention but the reality is that a drip cup cannot absolutely ensure dry litter. Any watering system, even with catch cups can be mismanaged in a way that results in wet litter. But one thing a drip cup system cannot claim is that it permits an enclosed watering system. It is an open watering system birds drink and share their diseases. Whether in a floor system or in an aviary housing pullets or laying birds, drip cups represent a potential health hazard to flocks. There is no point in negating the beneficial effect of installing an enclosed drinking system and keeping it free of biofilm when inches below the water-bearing pipes, the flock can drink and sip from contaminated drip cups. Numerous studies have shown that the bacterial level of water deposited in drip cups contains levels of E.coli quantified by laboratories as TNC (too numerous to count). Drip cups are unnecessary if nipple drinkers are correctly selected on the basis of dynamic discharge and operated at an appropriate water column pressure. Ziggity Systems has produced a series of instructional presentations in our Poultry Watering U series to demonstrate operation of nipple watering systems”
CHICK-NEWS: What other topics are considered on Poultry Watering U?
Robert: “The Ziggity Systems website <poultrywateringu.com> presents videos on topics including drinker management to optimize growth rate and feed conversion, bird welfare and prevention of biofilms. Poultry Watering U is so popular that editions on the website are dubbed in Spanish, Mandarin, Korean, Japanese, French, Polish and Portuguese”.
CHICK-NEWS: What message do you wish to convey to service people and flock managers?
Robert: “Measure broiler performance by feed conversion, live weight and livability. Many of our international customers use the European Performance Factor that integrates these variables into a single figure. Quality and post-harvest criteria including saleable yield including top-grade feet, downgrades and re-work should also be considered”.
“Insufficient intake of water will obviously detract from genetic potential as water is a critical factor in growth and for temperature regulation. For that reason, it is important to have the proper ratio of birds to nipples, the correct number of drinker lines based on house width, adjusting the height of drinker lines as the flock grows, adjusting column pressure based on beak size and preventing biofilm formation. But most importantly flock managers should be careful not to increase column water pressure too aggressively especially with young flocks. This will result in wet litter and release of ammonia creating a deleterious production environment.”
“Ziggity Systems has invested in research and evaluation to ensure that our range of drinkers for broilers, breeders, commercial layers, ducks and turkeys function in accordance with the physiologic needs of flocks”.
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