Broiler Ventilation Requirements In Response To Higher Welfare Standards. Bernard Green

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1 Broiler Ventilation Requirements In Response To Higher Welfare Standards Bernard Green

2 Topics Thermoneutral zone What is ventilation? 3 Ventilation systems Difficult climates Wet litter Control systems

3 Welfare Requirements Welfare requirements from a ventilation perspective These may differ from country to country Should ALL have one thing in common KEEP THE BIRDS COMFORTABLE Thermoneutral Zone

4 Thermoneutral Zone Temperature zone in which the birds are able to keep their body temperature constant with the help of physical heat regulation Lowest Critical Temperature (LCT) - lowest temperature in the thermoneutral zone Below LCT bird uses feed energy to warm itself Highest Critical Temperature (HCT) - highest temperature in the thermoneutral zone. Above HCT - birds can no longer dissipate their heat. They will start to consume less feed and production will drop as a result.

5 Cold Stress A Cool B Warm Heat Stress A Visual behaviour : ruffle feathers, huddle B Visual behaviour : hold wings away from body, pant

6 Ventilation Systems Outside of TNZ, bird behaviour changes We can see, interpret these changes (hopefully) We should ventilate based on these observations Every ventilation decision should be based on: Bird activity, comfort, and/or Air quality

7 Welfare view point: Comfortable birds Healthy birds Importance of TNZ Business view point: Healthy birds Better liveability Better FCR Better growth Better performance

8 Thermoneutral Zone TNZ does not remain constant It changes during the birds life Breed company guideline Set point temperature vs bird age ± 32 21ºC Is thermometer temperature all we need to monitor?

9 Temperature and Humidity

10 Windchill Example (UGA) Wind Chill ( C) Air Velocity (m/s) Example: Air temperature 30ºC; Air speed 3m/s Thermometer will show 30ºC; Birds will feel ±22 C

11 Outside Climate Climate has a major impact on house conditions Cold, hot and dry, hot and humid Hot and humid worst climate Cold we can add heat Hot and dry evaporative cooling is effective Hot and humid partial cooling + lots of air speed

12 Difficulty in Maintaining TNZ 3 Major contributing factors: 1. Bird s age changes daily 2. TNZ shifting every day 3. Ambient conditions can change hourly Keeping birds in their TNZ is not straight forward!

13 Ventilation System If you want to keep your birds comfortable, you need a good ventilation system Regardless of your location around the world Ventilation system includes: House Ventilation equipment Control system Management (stockman skills)

14 What Is Ventilation? Ventilation is all about control of: Where the air enters the house Where it doesn t enter How much enters Where it goes in the house (up, down, onto the birds) How fast it travels over the birds The temperature of the air (limited control) If you are hoping to keep birds in/near their TNZ, you must have control of the air

15 The Starting Point A good ventilation system starts with a good quality poultry house Most ventilation systems operate on negative pressure Houses must be well sealed, air tight This provides control of where air will and won t enter Easier to generate negative pressure to move air Insulation plays an important role Keeps heat out in hot weather, and in during cold weather A good house is: Well sealed, air tight Well insulated

16 Ventilation Systems Most houses should have 3 ventilation systems: 1.Minimum Ventilation 2.Transitional Ventilation 3.Tunnel Ventilation

17 Minimum Ventilation Operates at and below the set point temperature Heating is used to keep the birds comfortable Air is introduced through side wall inlets Inlets distributed along house length Inlets operate with negative pressure Direct the cold air away from the birds along the ceiling Fans operate ON/OFF (cycle timer) Manage cycle timer based on air quality

18 Transitional Ventilation Operates above the set point Purpose is to remove heat from the house Fans run continuously Air enters through side wall inlets Tunnel inlet is closed Inlets are equally distributed along length of house Air is still directed away from the birds along the ceiling

19 Tunnel Ventilation Air enters at one end of the house Air is pulled through the length of the house Air flow is on the birds Number of fans determine the air speed Use wind chill factor Try to control the birds effective temperature Evaporative cooling can be used to lower air temperature

20 3 Ventilation Systems Tunnel Ventilation (hot outside) Set Point Temperature Transitional Ventilation (too warm for minimum ventilation, not hot enough for tunnel ventilation) Minimum Ventilation (cold outside) The above could vary based on your annual ambient climate

21 Cool Optimum Warm Minimum provide heat, ventilate for air quality Transitional ventilate to remove heat, minimal air on the birds Tunnel move air over birds, wind chill, effective temperature

22 Difficult Climatic Conditions Minimum ventilation not usually a problem with a good house, enough heating (management) Transitional ventilation not a problem (management) Tunnel ventilation hot and humid conditions are a problem

23 Hot and Humid Conditions When birds are hot, they pant Panting uses internal evaporative cooling to release heat The more humid the air around the bird, the less effective is the panting process Cooling pads can be used to lower air temperature The more humid the outside air, the less cooling Evaporative cooling increases RH In hot, humid conditions air speed and air exchange is critical House design must be right!

24 Wet Litter Very often occurs during cold weather, winter Is it because outside is cold with high RH? No The colder it is, the easier to control RH Minimum ventilation is often more about controlling moisture (RH), than supplying fresh air

25 Phone App (PsychroApp) Available on Play Store and App Store

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27 Guideline : for every 10ºC you warm the air, RH will reduce by 50%

28 Why Do I Have Wet Litter? Question : If RH decreases when I warm the air, then why do I get high RH in my house and wet litter? Answer : The air gets warm, RH decreases The air absorbs moisture in the house from the birds, litter, drinkers RH increases CYCLE TIMER FANS MUST REMOVE THE MOISTURE If the fans do not operate enough, RH will increase and eventually put more moisture back into litter CYCLE TIMER SETTING IS CRITICAL

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30 Control Systems (and Operators) Control systems are responsible for how the ventilation system operates Thermometers/sensors measure temperature Temperature activates and deactivates fans The controller settings/program will determine the conditions in the house

31 Control Systems (and Operators) Bird behaviour should dictate controller settings NOT Controller settings determine bird behaviour Keep control systems easy to use and understand Be sure to keep teaching the controller what you are seeing in the house The controller is there 24/7 If you don t teach it what you see in the birds, don t expect it to look after them when you re not there

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