Ventilation, Moisture & Ammonia Lecture Notes 2022 PDF

Ventilation Lecture Dr. M. Q. Al-Natour, DVM, MPH, PhD Prof. of Avian Diseases & Public Health Department of Pathology & Public Health Faculty of Veterinary Medicine JUST, Irbid - Jordan E-mail: [email protected] ...

Ventilation Lecture Dr. M. Q. Al-Natour, DVM, MPH, PhD Prof. of Avian Diseases & Public Health Department of Pathology & Public Health Faculty of Veterinary Medicine JUST, Irbid - Jordan E-mail: [email protected]  Suggested Sites  http://www.scirp.org/Journal/PaperInformation.aspx?PaperID=25746  http://www.ncbi.nlm.nih.gov/pubmed/?term=Al-Natour+m  http://www.plosone.org/article/fetchObject.action?uri=info:doi/10.1 371/journal.pone.0002923&representation=PDF  http://www.virologyj.com/content/4/1/129  http://www.sciencedirect.com/science/article/pii/S01675877050007 60  http://www.ncbi.nlm.nih.gov/pubmed/17494605  http://www.researchgate.net/profile/Mohammad_Al- Natour/publications  https://scholar.google.com/citations?user=LldxtOQAAAAJ&hl=en  Objectives of ventilation 1. Remove water vapor; Removal of high humidity especially at winter in areas with high R.H. 2. Controlling temperature: Removal of Heat in summer; Excess heat around the birds will cause heat stress. 3. Remove harmful (toxic) gases particularly ammonia, CO and CO2. 4. Remove dust and air born pathogens.  Ventilation 1. Ventilation must eliminate the by-products of respiration and excretion of the bird and evaporation form the dropping and its litter. 2. Ventilation is also concerned with the control of temperature in the house and humidity. 3. Ventilation also has to change the air within the building so that the speed of the air's movement is uniform throughout the house. 4. Ventilation is necessary for the removal of dust and air born pathogens. 5. Considerable variation in the speed of air is required from winter to summer. In summer, a movement of at least five or six times the figure of winter is required.  In summer, a movement of at least five or six times the figure of winter is required Chicken Summer Winter type F3/min/lb. M3/hr/kg F3/min/lb. M3/hr/kg. of BW. of BW of BW of BW broiler 0.75—1.25 4.7—2.7 0.2 0.7 Layer 2.50—1.5 8.9—5.4 0.4 1.4  Air inlet volume: 4 f 3/1000 f 3 of air  Air inlet at 90—100 cm height (hot areas)  Air inlet at more (>) 100cm height (cold areas)  Regulator: regulate speed, direction of incoming air on the inlets.  In summer we should provide cold air from the outer inlets other wise hot air just go up because it is lighter (more hot ) than the house air and cause ventilation failure.  Therefore in badly ventilated house: 1. The stagnant air becomes warmer and more humid * The animal may die of "heat stagnation" * The litter becomes wet and the birds are uncomfortable. This will lead to uneven distribution of the flock in the building, and this in turn leads to unequal concentration of excreta and expired air and causes exacerbation of respiratory disease. * Wet litter Coccidosis. * Combination of high humidity and low temperature (common in winter) in poorly ventilated building is especially favorable to the viability and infectivity of many pathogenic micro-organisms. * Wet litter Production of ammonia. 2. Increase in the concentration of toxic gases, air-born micro-organism, dust and other particulate matters Ventilation system: 1. The Ventilation system should be kept simple and easy for the stockman to control. 2. The air should enter or leave the house evenly around the walls or along its length, i.e. there should be no dead space. 3. The incoming air must reach the bird at a low and uniform velocity.  Natural ventilation:  Not using mechanical Power to produce air movement. The motive power is provided from two sources; wind and temperature difference. 1. Cross ventilation: Opening on side walls:  This type of natural ventilation depends on external winds and will not function well in calm hot weather. 2. Stack effect:-A suitable opening or openings in the ceiling roof with openings on side walls. The air around the bird is warmer and lighter than fresh air, so it rises to the top of the building and then out. Fresh cold air (comes from out side through the side wall openings) falls naturally toward the floor, so the air is refreshed in the building.  The greatest the difference between outside and inside temperature the greatest the "stack effect"  * To ovoid down-draught, which is common in fixed open ridge, it is very useful to use "chimney" type outlet. It is a very good practice to have one or very few outlet Ventilation but a much larger number of smaller air inlets, as fresh air should come slowly all around the building and carefully baffled.  *As the outside temperature rises, the stack effect will become less and it might seem that Ventilation would become insufficient. However, the working of outlet chimney is usually assisted by the action of the wind and it's pulling or aspirating effect as it blows across the top.  Mechanical Ventilation: 1. Extraction of air from the roof: air is extracted from the roof while the air enters through inlets in the side walls. The height of air inlets should be suitable (about 90- 100cm) in the hot climate and higher in cold weather. 2. Extraction of air from side walls: Fans are placed on side walls and fresh air enters through opening in the roof. This system is useful if the width of the house is greater than 12m. 3. Cross ventilation: Exhaust fans on one side wall and opening (windows) on other side wall. Opening at a height of 90-100cm. Exhaust fans near the roof. This system is useful in a house with a width 12m or less.  Ventilation rate (air flow requirement): depend on weight of the birds & on out side temperature. Chicken Type Ventilation rate m3 /hr/kg body weight Winter Summer Broiler 0.75 2.8 – 4.7 Layer 1.50 5.6 – 9.4 Fan capacity = m3/hr  For example a house holds 5000 birds.  Suppose final weight is 1.8 Kg  5000 X1.8 X 4.5 = 40500 m3/hr  Suppose fan capacity is 5000 m3/hr  40500/5000 = 8 fans required Air flow can be lowered  1) Altering the speed of the fan by rheostat.  2) Operate only a part of the fans.  Fan capacity = m3/hr  For example a house holds 5000 birds.  Suppose final weight is 1.8 Kg  5000 X1.8 X 4.5 = 40500 m3/hr  Suppose fan capacity is 5000 m3/hr  40500/5000 = 8 fans required  Air flow can be lowered  1) Altering the speed of the fan by rheostat.  2) Operate only a part of the fans.  Ventilation Changing the air in poultry house. Good ventilation depends on: The temperature inside and outside the house, the speed, direction of wind and direction of house. Why ventilation? 1) Removal of toxic gases: CO2 , ammonia gas, CO has especial affinity to the Hb. 2) Removal of heat in summer (controlling temperature): excess heat around the birds well cause heat stress. 3) Removal of high humidity:-especially at winter in areas with high R.H.% (Relative Humidity)  Exhaust Fans Winter Type of chicken F3/Min/lb of BW M3/Hr/Kg of BW Broiler 0.2 0.7 Layer 0.4 1.4 Summer Type of chicken F3/Min/lb of BW M3/Hr/Kg of BW Broiler 0.75—1.25 4.7—2.7 Layer 2.50—1.5 8.9—5.4  Ventilation System 1. Gravity convection ventilation system:  Warm, moist air produced by the birds rises through an opening in the top of the building, causing partial vacuum at the floor, allows fresh air to enter along the sides of the building.  This system can be controlled by adjusting the openings along both sides of the house; these openings are usually covered with adjustable curtains.  Often fans will be placed within gravity convection houses to circulate air. But not to move air into or out of the house. 2. Forced air: A. Positive pressure ventilation system: Fan pushes air into a duct along the ceiling spanning (to extend over) the inside length of the house. 3. Negative pressure ventilation system: Typically employ exhaust fans mounted along one side of the building that pull air out of the house.  Exhaust fan move 0.06 cu m—0.23 cu m (2 cu ft/minutes/bird). Convection Ventilated House (Winter) Conv. Ventilated House (Summer)  Conv. Ventilated House 1. Air Inlet Volume = 4F3 / 1000F³ of air or air speed = 500 F³ /Minuets to prevent air currents inside the house. 2. Air Inlet @ 90-100 cm Height (Hot area) > 100 cm Height (Cold area) 3. Regulator- regulate speed direction of incoming air on the inlets. 4. In summer we should provide cold air from the outer inlets, otherwise hot air will just go up because it is more hot than the house air & cause ventilation failure. Ventilation system through long walls W= 12-18 M Ventilation system across the house Duct System Positive air pressure System Positive air pressure System Moisture in Poultry House Moisture in Poultry House:  The greatest problem of poultry housing.  Moisture in poultry houses is due to:  Water in fecal material (75-80%).  Water in the expired air.  About the only way to remove moisture is to increase movement of air (good ventilation).  If moisture is not removed litter become wet……so wet litter is an indication of bad ventilation.  Elimination of moisture is a problem in cold weather……why?  Humidity of the incoming air governs the amount of moisture it can hold….how? Unless it is removed from the house, moisture will increase when:- 1) Water consumption by the birds increases: a) Increase environment temperature. b) Increase salt content in the diet. c) A feed is pelleted. d) The energy value of the feed reduced. 2) House temperature decreases. 3) Humidity of the air increases. Ammonia in Poultry House  Ammonia is colorless gas, characteristic odor, lighter than air.  Formed as a result of decomposition of organic matter (fecal materials) containing nitrogen (uric acid).  Production of ammonia is increased as moisture increased in the litter, also as temperature increased.  Concentration measured in ppm. In poultry house; 50-100ppm  Slowing growth rate  Reducing appetite  Inducing kerato-conjunctive, and  Causing damage to the respiratory epithelium (lessen the activity of cilia) predisposing to respiratory infection.  For practical purposes, concentration should be kept below 50ppm (preferred 10ppm)  Man should not expose to 50 ppm for more than 8 hour. Reducing ammonia in poultry house: 1) Increasing airflow through the house. 2) Reducing the pH of the litter below 7. Phosphoric acid = 1.91 Kg/m2 Super phosphate = 1.09Kg/m2 3) Replacing the liter???  Ammonia Ammonia (NH3) is the primary aerial pollutant in poultry production houses, resulting from biodegradation of bird feces. Ammonia levels should not exceed 25 parts per million (ppm) in the house. Levels can be measured with an ammonia meter, but these are expensive. Inexpensive methods are ammonia strips, tubes. Ammonia strips. www.microessentiallab.com  The dual-gas (NH3 & CO2) portable measurement unit (PMU) Proceedings of the 3rd International Conference on Air Pollution from Agricultural Operations  Thermometers It is important to realize that the thermostats and/or controller sensors, located just a few feet above the floor, are often very different than those at chick level. This is primarily due to the fact that hot air is lighter than cold air. The best way to insure that we measure the proper temperature is to place thermostats/sensors three to four inches above the floor. Once the birds are a week to ten days of age the thermostats/sensors should be raised a couple of feet off the floor so the birds cannot peck at thermostat/sensors Thermometers In a typical broiler house you can see 6 thermostats. Have many disadvantages including the misreading between the different thermostats. Electronic thermostats is a better option with six wire sensors.  Electronic Thermostat www.engr.uga.edu  This Book issued in Arabic language, 2nd Edition 2007 is still valid today for Prevention & Control of Influenza Viruses in Human and Animal spp.  It includes all aspects of living, workplace, transportation (airports), Schools, Universities, Labs. & Food Safety in Houses & Restaurants in addition to Zoos, Live bird markets, Poultry Industry products: from Breeders to dining tables for Human Consumption & Public Health Issues.  Same principles of this book can be applied to Coved-19 Prevention and control since both viruses are sensitive to disinfectants & Similar Spread among Human population world wide