AUSTRALIAN POULTRY FORUM™

Can I please ask at what day do I candle egg to check for fertility is it at 5 days or longer and do I do it more than once

Conny,

It generally depend on the egg colour, type of candler and experience.

In realtion to egg colour you see the blood vessels at about 7 days, darker eggs around 10 days. The stonger the canling device the easier and more successful the candling. after a few goes you will very quickly know which are clear (unfertile) or full (fertile) eggs.

I also candle when I put the eggs into the hatching tray at day 18. I guess it confirms the chicks have made it to that stage of incubation.

Rhode Red

So if I play it safe and do them at 10 days then again at 18 days I should know for sure

Yes, to be safe try day 10 for the first candling.

Rhode Red

I wont hurt to give it a go at 5 days. Put the eggs you think are infertile together in the incubator and do them again after a few more days to see if you were accurate. You will soon work out when you can do them accurately.
With white eggs I have a pretty good idea about fertility at 3 days, but wait a week before I throw them out just to be sure.

I just didn't want to open the incubator too many times because they say it is bad for the eggs?

I'm impatient and candle regularly.

Opening the incubator is only bad for humidity and that is only critical at hatching.
Clucky chooks get off the nest every day for longer than it takes to candle eggs in the incubator. With most incubators the temp recovers very quickly once you close the door, but humidity takes a lot longer to recover.

I also incubate many species from Quail to Pheasants and my hatch dates have been known to be wrong due to the different incubation times. I even candle the eggs when I think they are due to hatch and dont move them to the hatching tray until I see the first break into the aircell. Once that happens it is generally a day until the first pips and another day until the first hatches. I have only had one ever hatch before I moved them to the hatching tray and it was fine.

Thanks goodoo you make some good points that I didn't think of

All the info you have been given is correct, with experience you will learn to identify the markers of afertile egg and an infertile one.
The candling device can be a simple globe in a box with a hole in the top to concentrate the light beam, a small strong torch held in one hand and the egg in the other hand sitting on the top of the gripped thumb and forefinger or a commercial candler (torch for the specific use) that allows you to candle eggs in the tray by placing the beam against the thick end of the egg.The process with any set up is best done in dim light or the dark at night to give you the best view of results.
A clear egg of any colour will allow free penetration of light.
A fertile egg will have a shadow in it, with experience you will soon learn even at what stage of developement the chick/duckling etc is at or has died at.
I usually do mine at 7 to 10 days to remove infertile eggs that can give off gases that can be detrimental to remaining eggs, it also frees up space for the next set if you are setting continuosly.I set on Fri night so the chicks hatch on the week-end and I can move and settle them into a brooder.
At a few days you will just see a dark spot near the air sac (the forming heart) an 5 to 7 days you will see a spider web effect stretching out from the heart( blood vessels) at 10 days you wu=ill see a definite shadow covering about 1/3 of the eggs contents(developing chick), once the egg is filled with shadow except for the air sac the chick is fully developed and ready to hatch(18 days), move to the hatching tray and do not turn any more allowing the chick the long hard job of chipping it's way out.
As you have been told opening the incubator is no real threat, I ope mine twice daily to turn the eggs.I top up the humidity tray with war/hot water and in summer or dry times spray the eggs after turning or candling with warm water to boost humidity quickly and to provide the extra needed at hatching. This is particularly important with duck/geese eggs.
Good luck.

Thanks very much Oaklands