| Summary Information |
| Type of
technique |
Health
& Management / Bird
Husbandry and Management / Incubation of Birds /
Techniques: |
| Synonyms and
Keywords |
See also: Candling |
| Description |
Egg flotation is a technique used in
monitoring the development of chicks within eggs.
- A mild disinfection solution (e.g. 10% povidone iodine) safe for use with eggs
should be used, at 43°C (110°F).
- The egg should be placed gently into the liquid and watched.
- A fresh egg will sink (total density is higher than water).
- An egg which is some way through incubation will float (total density is lower
than water), with the blunt end, containing the air cell, uppermost.
- An egg which is decomposing and contains much gas will float very high (as much
as half out of the water), on its side.
- Movement may be detected in a floating egg after approximately two thirds of the
total incubation time (e.g. by 21-22 days of incubation in crane eggs; B115.4.w1).
- The egg should be removed from the disinfectant after a maximum of one minute and
returned to incubation.
|
| Appropriate Use (?) |
- Mainly used with eggs in which a thick shell and/or shell pigmentation makes
candling difficult, or in situations where a suitable light source for candling is not
available.
- May also be used as an adjunct to candling.
|
| Notes |
- If no movement is seen on the first flotation, the procedure may be
repeated one or two days later.
- Eggs which fail to pip when expected may be floated to determine if the
chick is still alive.
|
| Complications / Limitations / Risk |
- Flotation in cool water may cause the contents of the egg to contract and
draw bacteria into the egg.
- Flotation for too long risks asphyxia and overheating of the embryo.
|
| Equipment / Chemicals required and Suppliers |
Water, disinfectant, method
of heating water/keeping it warm, thermometer to monitor water temperature, suitable
container. |
| Expertise level / Ease of Use |
Not difficult to perform,
but experience makes interpretation easier. |
| Cost / Availability |
Inexpensive. |
| Legal and Ethical Considerations |
Flotation for too long may
result in asphyxia and overheating of the embryo. |
| Author |
Debra Bourne |
| Referee |
|
| References |
B106, B115.4.w1, V.w5 |
