Respiratory problems are among the most important problems facing the poultry industry in Egypt. It is the first problem in poultry breeding farms, regardless of the type of poultry reared in these farms (broiler breeders- layer breeders- commercial broilers – commercial layers-native breeds). There are many factors that help to spread these respiratory problems in poultry farms such as:
- Little experience of the of the poultry farms managers in general about the bases and the principles of poultry farms ventilation, especially between months of winter and months of summer.
- Lack of adequate ventilation systems in these poultry breeding farms, where 70% of these farms owned by small farmers and these farms lack the appropriate design that allows ventilation rates required for these farms.
Most of the farms have a desert cooling system to reduce the impact of high temperatures in summer months. However, the actual implementation of this system does not provide the desired ventilation volume for the herds grown in these farms.
Most poultry farms belonging to small owners, which account for about 60% of the poultry production in Egypt, follow the open system in ventilation. This system depends on the human factor in regulating ventilation windows. Usually, the capacity of these farms ranged from 5000 to 10,000 birds and served by 1 or 2 of the workers and this number is not sufficient for the good follow-up of ventilation especially in the winter and this leads to a disturbance in ventilation.
During winter months, due to lack of supply of fuel used in heating, the owners of these farms try to raise the temperature of the farms by reducing the ventilation and this leads to a high proportion of ammonia gas and exposure of the herd to respiratory stress.
In recent times, the use of sources of heating placed inside the farms amid the birds and these sources are not equipped with a chimney to get rid of combustion exhaust f outside the farm and this leads to the accumulation of combustion exhaust f within the farm and this exposes the birds to the problems of respiration, especially during the first two weeks of life.
Receiving the herd in the first week of age with high densities per square meter, where the density of the housing may reach about 100 chicks per square meter, which negatively affects the ventilation and expose the herd to the respiratory stress from the beginning of life.
Many poultry farmers resort to delaying the operation of heating devices before the receipt of chicks two or three hours, so as to save fuel, which leads to the failure to reach the temperature of the litter and walls to the appropriate level to receive the flock and this exposes chicks to cold at the beginning of life.
In the poultry farms assigned to the replacement flocks of broiler breeders or of layer breeders, the period of lighting decreases and reaches to 8 hours and the period of darkness 16 hours and during the dark hours there is no good follow-up to the situation of ventilation in the farms.
The chicks are often transported from the hatchery plant to the farm by cars that are not designated for this purpose. They do not provide the suitable environment for transporting the chicks, and the transport process may take 3 to 6 hours and on unpaved roads with lots of dust.
Keeping chicks after hatching in a temperature not appropriate for keeping chicks lead to heat stress from the age of one day and this happens as a result of interest in measuring the temperature of the room without focusing on the temperature of the boxes used for keeping the chicks and this often occurs in the hatcheries used for hatching native breeds.
In poultry farms that follow the closed system of breeding, air intake rates may be disproportionate to the air inlets or vice versa. This occurs because farm managers ignore that frequent maintenance operations result in poor performance of these devices.
Poultry farm managers often do not pay attention to the fact that the needs of farms with more than 30% moisture in litter need more ventilation than their counterparts.
The presence of any of the preceding factors alone or in combination leads to the emergence of respiratory infection with one or more of the following causes:
- Mycoplasma.
- Newcastle.
- Infectious Bronchitis.
- Infectious laryngotracheitis.
- E.coli.
- H5N1.
- H9N2.
To overcome these chronic problems, it is necessary to do the following:
- The managers of the poultry farms must be fully aware of the required ventilation requirements, which are calculated mainly on the total living weight within the farm and is related to the efficiency of ventilation machines used.
- Pay attention to the efficiency of heating devices and make sure that the exhaust produced from these devices does not escape into the farm.
- Providing an adequate number of workers in the poultry farms that follow the open system in ventilation, for the accurate and continuous monitoring of the windows of the entry of air, especially in the winter.
- Concentration in the hatchery and transport of chicks on the temperature of the boxes in which the chicks exist and make sure that temperature sensor is in the right place.
- Avoid any factors that help or lead to thermal stress of the herd.
