The hatchery is a vital link in a breeding operation. As ours is still developing, my aim is to make it a suitable, simple, effective and reassuring tool, delivering good hatchability as well as healthy, vigorous chicks. The impact of incubation on chicks is too often underestimated: many rearing problems stem from egg management that is not sufficiently mastered.

After studying the various points to master in a hatchery, one of them had always been my weak spot: egg storage. After reading and studying a number of documents, I managed to build a synthesis that forms my basis for reflection. These elements may help to understand the different parameters to take into account and, I hope, to change a few unnoticed bad habits.

After collection, sorting and disinfection of the eggs comes the storage period preceding incubation. This period is decisive for a successful incubation: the longer it is, the more certain parameters must be controlled.

Pre-warming on arrival

There is an embryonic stage which, at the start of incubation, promotes the regeneration of cells that died during storage. To reach it, it is advised to pre-warm the eggs on arrival at the hatchery for 6 hours at 37.7-37.8 °C (on eggs laid the same day and/or the day before) before storage. This method reportedly improves hatchability by up to +4% for eggs stored 4 to 13 days.

Storage temperature

Temperature is a key element. Physiological zero (the temperature above which embryonic development occurs) lies between 20 and 29 °C (specialists disagree). Storage between 27 and 35 °C causes malformations. The recommended temperature can be split by storage duration:

  • < 2 days: 19 °C
  • 3 to 7 days: 16 °C
  • 8 to 21 days: 12 °C
  • > 21 days: 10 °C

Where there is only one storage area for all the eggs, with a certain spread of duration, the most commonly used temperature is 15 °C.

Humidity

Humidity is a basic parameter to respect: for a short duration the level should be 75% (1-2 days) and up to 90% for storage over 6 days.

Turning

Turning the eggs is an overrated factor. Under good storage conditions it has been found to have no effect, except over long periods (over 21 days) and/or with old breeders. A "classic" hatchery uses a fairly short storage time (5 days) and turning is very rarely set up; for longer durations it is often used by default.

Delay to hatching

Storage delays embryonic development at the start of incubation. Each day of storage causes a 45-50 minute delay to the final hatch; for 14 days of storage that is 12.2 hours of accumulated delay. A hatch is always more efficient with a short hatch window (the gap between the first and last chick). Pre-warming helps prepare incubation and thus allows old eggs to partly catch up their expected delay.

Two pre-warming methods

The simplest and most used consists of placing the eggs at 25-27 °C and 50-55% humidity for 12 hours; as hatcheries are mostly air-conditioned to 25 °C, the eggs are often placed in the corridors — the storage room can also be temperature-controlled, and some pre-warm directly in suitable incubators.

The second solution is to raise the eggs gradually to incubation temperature, from 19 °C up to 37.8 °C, which requires a programmed temperature ramp.

Examples of results obtained

  • storage over 4 days: > 93% hatchability
  • storage over 13 days: > 78% hatchability

For an amateur breeder, it is very difficult to master some of these parameters, but it raises awareness of notions that should help improve a way of working.

Further reading: Our hatchability rates measured by breed · Selection work: creating a variety · Raising your chicks

Cyril Névot — Elsanor farm