GOOD VENTILATION is critical to a healthy, high performing flock of broilers.
It provides birds with fresh air, helps regulate temperatures and, crucially, expels water from sheds, helping to keep litter dry and friable.
See also: How to set up and operate ventilation for broiler chicks
Getting it wrong will soon lead to wet floors, which in turn will cause conditions like hock burn, pododermatitis and poorer air quality.
That’s why beef and poultry farmer Christina Hutchings chose to study ventilation and its influence on litter quality for her scholarship under the Tesco Future Farming Foundation.
The project took more than two years to complete and saw Ms Hutchings consulting with a wide range of experts and her own research to produce the report, which she hopes will offer fellow broiler farmers at the very least ‘a few gems’ or things to consider on their own farms.
The full report can be accessed here.
And see below for some of the hints and tips she picked up throughout her research.
- You cannot keep litter dry without air movement.
Mike Czarick, University of Georgia, Poultry Science Department, USA
- Newer sheds are generally much tighter (few gaps and cracks) than older houses, which means you have a lot less time to rectify ventilation before things go wrong and the litter caps over.
A vet during an on-farm visit
- Have your heaters on the sidewalls, where its coldest, not in the middle of the house.
Christina Hutchings
- If your floors are not well insulated or not pre-heated, it is better to use a thicker layer of bedding.
Aviagen’s ‘Management tools to reduce FPD in broilers’
- High relative humidity outside is no excuse for wet litter.
Bernard Green, Aviagen (Asia)
- Using your senses to assess the house conditions is important. But don’t hurry – wait until you have been in the house for 5 minutes before judging it, especially if it’s cold outside.
Justin Emery, Draper Ventilation UK.
- Relative humidity should be monitored and used to make adjustments to the ventilation rate to keep it between 40-60%. This will help maintain floor conditions provided inlets, birds, drinkers, etc., are managed correctly.
Professor Brian Fairchild, University of Georgia, Poultry Science Department, USA
- Use regular mercury thermometers hung up in your houses to sense-check your regular temperature sensors.
Christina Hutchings
- You don’t feel heat and cold in the same way as the bird
Justin Emery, Draper Ventilation UK
- Minimum ventilation rates should not be based on kilos of birds, rather, house relative humidity.
Mike Czarick, University of Georgia, Poultry Science Department, USA
- What the computer says the temperature is and what the bird says it is may not be the same.
Justin Emery, Draper Ventilation UK
- Poultry lose 60% of their heat through evaporative (latent) heat loss and 40% to the air around them (Sensible heat loss), making them more sensitive to relative humidity than humans.
Professor Brian Fairchild, University of Georgia, Poultry Science Department, USA
- Always allow for the wind-chill from air movement. This varies with bird age, outside temperature, airspeed etc.
Justin Emery, Draper Ventilation UK
- Cold air is dry air – it can help dry out litter even if outside humidity is high.
Justin Emery, Draper Ventilation UK
- We must have good quality minimum ventilation inlets (and overall system) and know how to manage them properly to get the best from them.
Christina Hutchings
- If you properly control relative humidity levels 90% of the time, your carbon dioxide and ammonia levels will be fine.
Mike Czarick, University of Georgia, Poultry Science Department, USA
- The same settings during both summer and winter may give different results.
Justin Emery, Draper Ventilation UK
- Adjust the temperature probe as the birds grow, so it is always at bird-height
Christina Hutchings
- The same inlet pressure can give very different results in different houses at different times of year.
Justin Emery, Draper Ventilation UK
- Most inlets need to be open to their ‘minimum working gap’ if they are to work well.
Justin Emery, Draper Ventilation UK
- Using minimum ventilation charts is dangerous because they often have little correlation to what is actually happening on a farm
Mike Czarick, University of Georgia, Poultry Science Department, USA
- Higher pressure is usually better in wider houses in cold weather.
Justin Emery, Draper Ventilation UK
- Have enough heat and don’t be afraid to use it – well-distributed heat that is available throughout allows us to carry out good minimum ventilation rates, removing stale air and moisture without chilling the birds.
Christina Hutchings
- You can position fans anywhere in a house as inlet pressure should be the same. But if the fans are all at one end, low pressure can result in short-circuiting of airflows.
Justin Emery, Draper Ventilation UK
- One of the best overall tools for determining minimum ventilation rates is a water meter.
Minimum ventilation rates are proportional to water usage. If water usage increases 30% in a week then so do minimum ventilation rates.
Mike Czarick, University of Georgia, Poultry Science Department, USA
- Use a smoke machine to test ventilation patterns.
Justin Emery, Draper Ventilation UK
- Cold concrete floors result in condensation and poor litter. But don’t overheat the floors as chicks may need to cool themselves if house temperature is too high.
Justin Emery, Draper Ventilation UK
- Preferably use sidewall exhaust fans, rather than ceiling/chimney ones as these don’t interfere with that nice bank of warm air you need to use from the peak of the house. If you already have ceiling exhaust fans, then extend the chimney down further into the house to avoid exhausting the warm air from the peak.
Bernard Green, Aviagen (Asia)
- We must have good quality minimum ventilation inlets (and overall system) and know how to manage them properly to get the best from them.
Christina Hutchings
