Why does the hatch rate in broiler chick production decrease? An examination of the causes, consequences, and improvement strategies.

What causes a low hatch rate in broiler day-old chick production?
A review of the causes, effects, and ways to improve
Introduction
In the modern poultry industry, hatchability is one of the most important indicators of success in the broiler meat supply chain. Hatchability refers to the percentage of eggs that successfully hatch into chicks. Under ideal conditions, this rate can reach 85–90%, but in some farms, it drops to below 75%. Such a decrease results in significant economic losses and reduced productivity.

1. Quality of Hatching Eggs
Age of the breeder flock: Very young or very old flocks have lower fertility rates.

Breeder flock nutrition management: Deficiencies in vitamins (A, D, E), amino acids, and minerals (such as selenium and zinc) directly affect egg quality.

Respiratory and viral diseases such as infectious bronchitis or Newcastle disease can reduce egg fertility.

2. Conditions for Handling and Storage of Eggs
Storage temperature of hatching eggs: Eggs should be stored at a temperature of approximately 16–18°C and humidity of 75–80%. Any fluctuations negatively affect embryo viability.

Storage duration: Storing eggs for more than 7 days before incubation reduces the hatch rate.

Transportation conditions: Excessive vibration and temperature shocks during transport from the farm to the incubator cause embryo mortality.

3. Improper Incubator Settings
Incorrect temperature and humidity: A deviation of even 0.5°C from 37.5°C can increase embryonic mortality.

Insufficient or irregular egg turning: Mechanical turning of eggs during the first 18 days is crucial.

Inadequate ventilation: Increased CO₂ or decreased oxygen levels in the setter and hatcher reduce hatchability.

4. Pathogenic Factors in Incubation
Bacterial contamination of eggs (such as Salmonella, E. coli, Pseudomonas): can cause early embryonic death or defective chicks.

Insufficient disinfection of incubation rooms and equipment is a common cause of egg contamination during the setter and hatcher phases.

5. Human Error in Incubation Management
Lack of calibration of thermostats and hygrometers causes incorrect readings.

Incorrect timing of transferring eggs from the setter to the hatcher: transferring too early or too late reduces the hatch rate.

Poor process data monitoring: Failure to record and analyze data leads to repeated management errors.

6. Genetics and Breed
Genetic differences between breeds such as Ross, Cobb, or Hubbard cause variations in fertility and hatchability rates.

Reverse heterosis in some genetic lines can lead to reduced hatchability efficiency.

Proposed Strategies for Improving Hatchability Rate:
Strict control of nutrition, health, and hygiene of the breeder flock

Continuous monitoring of the quality of hatching eggs on the farm and in storage

Continuous training of hatchery staff in handling, setting, hatching, and disinfection procedures

Use of modern equipment with precise sensors

Analysis of incubation data to optimize settings

Conclusion:
A low hatch rate not only means a reduction in day-old chicks but also indicates a disruption in one of the stages of the production chain. Analyzing the causes and addressing weaknesses in nutrition, transportation, incubation, and hygiene can restore hatchability to acceptable levels and ensure the profitability of the industry.

Suggested References for Further Reading:
“Poultry Production” by Leslie E. Card and H.H. Mitchell

“Hatchery Management Guide” – Aviagen Ross 308 Manual

Articles published in Poultry Science Journal

Guidelines from hatchery companies such as Pas Reform, Petersime, and Cobb-Vantress