In Northwest China, the large day–night temperature differences, frequent blowing sand, and dry air in spring pose major challenges for ventilation management in chicken houses. Scientific ventilation management not only helps protect the health of the flock, but is also key to improving egg production and economic efficiency. Drawing on the spring climate characteristics of Northwest China, the author systematically explains the technical points for ventilation management in large-scale layer farms.
I. Spring Climate Characteristics in Northwest China and Ventilation Challenges
Spring in Northwest China (3-5 months) has the following notable characteristics:
Large day-night temperature difference: Temperatures rise quickly during the day and are low at night. The difference can reach more than 15℃, easily causing stress in the flock.
Frequent wind and sand: Spring is windy and often accompanied by sand and dust, placing high demands on filtration at poultry house air inlets and air quality control.
Dry air: Low humidity can easily lead to increased dust in the poultry house and trigger respiratory diseases.
II. Core Principles of Spring Ventilation Management
1, minimum ventilation mode (night and early morning)
Objective: Remove harmful gases (ammonia and carbon dioxide) and excess moisture from the poultry house while ensuring the flock does not get chilled.
Operation: Use timed, cyclic ventilation (for example, run for 2 minutes, stop for 3 minutes), setting the fan run time according to the flock’s age in days and the outdoor temperature. Control the air velocity at the air inlets to 3-4 meters/second to ensure cold air is thoroughly mixed and warmed before reaching the center of the poultry house, preventing drafts from blowing directly onto the birds.
2, transitional ventilation mode (daytime)
Objective: Increase air exchange while maintaining a stable indoor temperature to reduce dust concentration.
Operation: When the outdoor temperature rises above the set temperature, gradually increase the number of fans switched on or extend their operating time. Observe the flock’s behavior carefully. If the chickens are panting with their beaks open, ventilation is insufficient; if they huddle together, they are being exposed to a direct cold draft.
3, Tunnel Ventilation Mode (High-Temperature Periods)
Objective: Address high midday temperatures by cooling through air speed.
Operation: When the coop temperature exceeds 25°C, consider starting tunnel ventilation to use the wind-chill effect to lower the chickens’ perceived temperature. Be sure to close the ventilation inlets and open the cooling-pad air inlets (but do not turn on water to the cooling pads at this time, to prevent excessive humidity).
III. Key Control Points and Operating Details
1, Temperature Control
Set temperature: The optimal temperature during the laying period is 18-25°C. It is recommended to set the target at no more than 23 degrees. Spring management should follow the principle of “adjusting temperature based on the chickens’ condition”—that is, fine-tune the ventilation rate based on the flock’s behavior (such as whether the chickens are evenly distributed and whether they are panting), rather than relying rigidly on thermometer readings.
Preventing temperature-stress: Nighttime and the early morning hours are challenging to manage. Set the temperature-control program and differential levels in advance to ensure stable temperatures at night and prevent the chickens from getting chilled and catching colds.
2, humidity and dust control
Humidification: In spring, humidity in the Northwest is often below 40%. When temperatures are higher around midday, intermittent misting can be used via the fogging system to increase humidity ( 10-15 seconds per cycle), raising it to 50%-60% and effectively settling dust.
Dust removal: Clean the air-inlet filters regularly to prevent sand and dust from clogging them and affecting airflow; strengthen disinfection in the presence of the flock to reduce the attachment of pathogenic microorganisms.
3, ventilation window management
Angle adjustment: The angle of the air inlet deflector should be adjusted in real time according to the outdoor temperature. In particular, the lower the outdoor temperature, the larger the deflector angle should be (upward), so that cold air is directed toward the roof and then falls after mixing with the warm air.
Sealing: Check the sealing of poultry house doors and windows, the area around the wet curtains, and the manure channel openings. Eliminate air leaks to ensure stable negative pressure in the ventilation system.
Four, Emergency Plan
Strong winds and dust: Generally, add a light-blocking wind shield to the small window outside the poultry house, making it as long as possible to keep out wind and dust. The small window on the leeward side can be opened wider. At the same time, reduce the fan speed while maintaining the minimum ventilation rate.
Spring cold snaps: When temperatures suddenly drop, promptly reduce the number of operating fans or limit the ventilation level, returning to minimum ventilation mode. If necessary, activate backup heating equipment to prevent cold stress in the flock.
Five. Summary
The key to spring ventilation management in Northwest China is “dynamic adjustment.” Managers should closely monitor weather forecasts and, together with data from temperature and humidity sensors inside and outside the poultry house and the flock’s actual condition, flexibly switch ventilation modes. Only through careful management that balances heat preservation with air exchange, and dehumidification with dust reduction, can a stable, comfortable production environment be created for laying hens, enabling high and stable production in spring.