Egg Turning Frequency and Duration During Incubation

During incubation of chicken eggs, turning is done at least ______ times in a day up to ______ days for optimum hatchability:

Correct Answer: 8 times, 18 days

For optimum hatchability, eggs should be turned at least 8 times per day during the first 18 days of incubation. Turning is stopped during the last 3 days (days 19–21) when the chick is preparing to hatch.

Why 8 Times Per Day?

• Each turn is at 45° vice-versa (alternating directions).
• Minimum of 8 turns = one turn every 3 hours approximately.
• Modern commercial incubators may turn eggs automatically every hour.

Why Turning Stops After Day 18?

• After transfer to the hatcher tray, eggs are placed horizontally.
• The chick needs to orient its head toward the air cell (broad end) for internal pipping.
• Turning during this phase disturbs the chick and can cause malposition → dead-in-shell.

Critical Incubation Parameters Summary

• Temperature (Days 1–18): 37.5–37.6°C | (Days 19–21): 37.2°C
• Humidity (Days 1–18): 60% R.H. | (Days 19–21): 70% R.H.
• O₂: 21% | CO₂: max 0.5%
• Turning: 8 times/day, days 1–18 only