As we know that bird needs large amount of energy to maintain their selves and production. For this energy, they required good quality of feed which have higher Cp value besides this some other factors are also required for best yield  among them ventilation is very important factor which directly effect on birds.

By : Dr.Ujala Mehtab, Abdul Samad and Muhammad Junaid shahid

Affiliation Institute : Muhammad Nawaz Sharif University of Agriculture Multan

 The role of ventilation

Good ventilation  help out bird to give higher production while poor ventilation effects bird and in result bird lose its production and also cause death or mortality of bird. The process of metabolism increase humidity rate as when feed breakdown and metabolic water is releases(Kenneth Mellanby., 1936) . Birds required to excrete out this humidity so bird excrete those humidity through respiration and feces and this humidity increase body temperature sensation of the birds. The other thing is that bird produce heat during their process of metabolism as we know when large particle converted in small it release energy in the form of temperature so the temperature of the poultry house increase as we know  birds don’t have any ability to sweat, so they decrease down their temperature trough breathing, panting and vigorous flapping(Manual of Poultry).So we need to excrete out extra temperature and humidity from the shed through proper ventilation system by which we can give proper comfort to our birds in result bird give us proper weigh or meat production and egg production. Birds release extra body heat by four methods

  • Convection
  • Conduction
  • Radiation
  • Evaporation


                      Birds release their extra heat through movement of air


                  Heat exchange through direct contact


                 Heat is emit in form of heat radiation


              As we evaporation give cooling effect so by breathing heat is released from bird’s body

Advantages of Ventilation

  • Removal of extra heat from shed.
  • Removal of toxic gasses from shed
  • It protects birds through heat stress according to a survey 30% mortality occur in bird due to heat stress
  • Reduce in humidity reduces ammonia level in the shed
  • Reduce in humidity save litter cost as we need to change litter if humidity increase in litter.

Ventilation basics

  In order to understand ventilation we required to understand some basics

Controlled environment

  It is a house which is completely controlled by a system in which we gave commands according to our requirement it will manage the house accordingly. This system consist of meters, sensor and controllers.


                 Control the temperature, humidity, feed and water requirements


         Sense humidity and temperature

Meters         Measure different environmental components e.g gasses, temperature and humidity.


A machine which provide air or machine below air by the movement of its wings This machine is main equipment for ventilation which help out to exchange air in the shed


     A machine which help out to expel out extra heat and gasses from shed. It expel bad air from house

Minimum ventilation

A term which refer to ventilate the house by using low amount of air this system is used in winter system as we need to maintain temperature as well as humidity in winters.

Types of pressure in ventilation

Negative pressure

xIt is most common system in which we use exhaust fan to expel out bed air from house

Neutral pressure

Right Arrow: Neutral pressure both side This system is also resemble to  previous but it require large number of Fans as temperature in and outside of the shed will be same during this system that’s why this type of system is  called Neutral ventilation system

Fans                                                                      Ventilate the house

Ventilation systems

Natural ventilation

It is ventilation system which is normally used in open houses and applicable in only some areas. Normally shed build according to air movement. In south Punjab direction of poultry house will be east to west as air passes through the shed, temperature and humidity maintained. We cannot use this system in some areas as ammonia level is cannot be control in areas of higher humidity through natural ventilation (Osorio, R., 2016).


No equipment is used

Tunnel system

  • System is used in summer
  • Tunnel Fans are used
  • Large amount of air below in shed which minimize temperature and temperature

General recommendations

Air inlet: Air inlet should be in a house through which movement of air occur

Size of inlet: size of inlet depends upon the area of house

Location of the house:

While selecting the location of house keep in mind some points in respect to ventilation

  • House should not near the factory
  • Temperature of area
  • Weather of area

Environmental gas meters:

It is very important to measure the environmental gasses as it is compulsory to know the level of gas higher concentration of gasses can cause mortality.

Technical and professional assistance:

Technical assistance is very necessary for installing the equipment and managing proper ventilation.

Ventilation Requirement per bird

Carbon Dioxide                   Above 30%1%
MethaneAbove 5%1%
AmmoniaAbove 500 ppm40 ppm
Hydrogen SulfideAbove 500 ppm40 ppm
OxygenBelow 6 %16%

  Gases Ratio (Lethal and desirable)                                       

Tips to manage Temperature

  • Use fans and exhaust
  • If Temperature is out of control in summer use tunnel ventilation
  • In winter use Brooder and heater
  • Minimum ventilation is recommended in winter
  • In open shed when temperature exceed to its limit throw water directly on birds
  • Further an extra equipment of every equipment should be there if someone out order use supplement of those equipment


Poultry is most profitable and important sector as it is contributing about 5% in our total gdp while 11.7%(survey 2018-19)  share in Agricultural Gdp. Ventilation is very important for good performance and  bad ventilation could cause mortality and also against poultry bird’s welfare. Good ventilation can also help out in achieving higher production goals and in result provide profit to the farmer Therefore, knowledge of ventilation is very important for a former this article will provide some basic knowledge

of ventilation to an industrialist or farmer or domestic farmer too. It is an effort for peoples who don’t know about importance of ventilation further we also gave some tips to manage the ventilation.


  1. Manual of Poultry
  2.  MELLANBY, K. Humidity and Metabolism. Nature 138, 124–125 (1936).
  3. Osorio, R., 2016
  4. Economic survey of Pakistan 2018-19