CANDLING
Poultry
Candler
Approximately 6 hours prior to placing eggs in the setter they should be moved from the egg-cooler room to normal room temperature. Here, atmospheric air condenses over eggshell and form water droplets over eggshell, which is called as ‘Sweating’. It is advantageous to warm eggs before placing them in the incubator by avoiding creation of low temperature in the machine by placing cool eggs directly.
How to differentiate fertile and infertile eggs
- Fertile egg : ( In blastoderm) Central white clear with outer clear ring
- In fertile egg : ( In blasto disc) Asymmetrical Central outer clear ring is not clear.
Observations During Candling
First Candling Done on 7th day
Examine and determine normal embryo development at 6 or 7th day (preferable 7th day).
- Fertile egg: Red spider like radiating movement giving darker shadow.(mass inside & movement of embryos).
- Infertile egg: The eggs are clear in appearance
- Dead embryos: Mass inside but no embryo movement. (A small spot fixed in position)
Second Candling is done on 16th or 18th day of Incubation. (Preferable 18th day).
- Dead embryo: No blood vessels and no movement of embryo.
- Live embryo: Blood vessels and movement of embryo clear under candling.
Grading the Chicks:
No chick below the minimum standard must be allowed to go to a customer. Some standards for quality are, 1) No chick deformities 2) No unhealed navels 3) Above a minimum weight 4) Not dehydrated and 5) Stand up well.