Ventilation is one of the most important principles of raising broiler chickens in farms, which is the only key to reduce the respiratory problems of the bird and to reach the highest productivity and the highest conversion rate.
Ventilation is an important factor that controls the productive performance of birds. Poor ventilation leads to low weight and food conversion rate, as well as respiratory diseases that increase the mortality rate, reduce the immunity of birds and make them susceptible to bacterial and viral diseases and eventually develop respiratory disease Chronic Respiratory Disease (CRD), which is difficult to treat and causes significant economic losses, and poor ventilation leads to increased incidence of Hock Burn.
What is the main importance of ventilation in poultry houses?
1- Elimination of many harmful gases in the respiratory system of the bird, such as ammonia and gases resulting from the operation of heaters and replace the proportion of carbon dioxide gas by oxygen to breathe birds well.
2- Heat distribution inside the poultry houses and get rid of excess heat.
3- Distribution of moisture inside the poultry houses and disposal of excess moisture..
4- Get rid of bad dust.
There are several factors that control the amount of air inside the poultry houses which must be considered:
• Building type (insulation grade).
• Relative temperature and humidity inside and outside the house.
• The type and age of birds.
• Intensity of birds inside the house.
Ventilation varies in the summer than in the winter season. Ventilation in the summer season is the highest rate in order to rid the birds of excess heat resulting from birds inside the house. Ventilation in the summer is much easier than ventilation in the winter.
While ventilation in the winter (less ventilation rate) is intended to renew the house air to prevent the increase of moisture inside the house while at the same time maintain the temperature of birds and heating system and control moisture of the litter. Through good ventilation, the ammonia, dust, carbon dioxide rarely occur problems within the amber.
Poultry farms are generally ventilated in two ways:
The first system:
Ventilation using Exhaust Fans: in this system, the air is withdrawn from the inside of the farm through suction fans and this creates a low pressure inside the farm and as a result, the air enters from outside the farm into the system and also called this system Tunnel Ventilation System.
The second system:
Ventilation through the opening of side curtains (Side-Wall Curtains) where ventilation is by opening and locking the side curtains.
The two systems may be put together so that the curtains can be locked and the closed system is operated with suction fans and this is at high and low temperatures.
The following table shows the incubation temperature and the lowest ventilation rate of the meat type birds by age of birds
First week 0.5 m 3 / kg/hour at 30°C
Second week 1.0 m3 / kg/hour at 28°C
The third week 1.7 m 3 / kg/hour at 26°C
Fourth week 2.6 m 3 / kg/hour at 24°C
The fifth week 4.5 m3 / kg/hour at 22°C
The sixth week is 5.5 m3 / kg/hour at 22°C
Note: - Optimal humidity of the bird 50% to 70% relative humidity and degree of warm-up of birds after the fourth week from 18 to 24 °C.
Therefore, the amount of air to be renewed in the amber must be calculated and fans should be operated. For example, if there is a farm with 10,000 birds in the second week of life - the amount of air to be renewed is: 10000 * 1 = 10000 m3 / h.
As most poultry fans are of high capacity, these fans must be operated on a timer in order to adjust the amount of air to be renewed. Here we must mention the efficiency of the fan, which is the amount of air that can be renewed. The actual efficiency of the fan must be measured by a device that measures the efficiency of the fans and should not depend on the amount of air that the fan exits at the time of purchase. This is at 0 psc (static pressure gauge). In general, only 85% of the air intake released by the fan and the code is counted in fan data. If it is written that it graduated 45 thousand m 3 / hour, the amount of air that will emerge from the poultry house is about 38 thousand m 3 / hour (calculated static pressure inside the amber 0.1).
The following table shows the minimum ventilation rate for 10,000 birds and suction fans of 40000 m3 / h (actual efficiency) at different stages of life and with temporary use for 10 minutes.
Effects of poor ventilation on the chicks inside the farm
- A lot of respiratory problems such as mycoplasma and many more.
- Inflammation of the membranes of the eye due to the high proportion of ammonia inside the poultry house for poor ventilation.
- Stressed strong on the chicks and thus cause the decline of immunity and face diseases and underdevelopment.
- Little feed intake and idle on the farm.
- High Humidity Within the house and the fungal problems of coccidiosis begin to appear inside the farm.
- Efficiency of the rate of conversion and food is low and, therefore, we get the weight of a discount.
Effect of good ventilation on the chicks
- We do not find respiratory problems.
- Increase the appetite of the bird.
- Disappearance of the smell of ammonia in the house and reduce the problems of the eye.
- In the end, the efficiency of the conversion rate rises and we get high weights.
Side wall exhaust fans
Open side farm