I finally figured out how to candle But now I'm not sure what I am looking at The black spot in the "yolk" means it's fertile, right? I have some that I cant find the black spot but have veins surrounding the shell, does that make sense? Are those fertile? It has been 7 1/2 days since they went in. Is it possible the ones that look blank could still be fertile? What about turkey and guinea eggs? Does it take them 7 to 8 days to show fertility as well. I know it's 3 weeks for chickens to hatch, 4 weeks for turkies, what about guineas? Questions, questions, questions, one of these days I will figure it out.
You should be looking for the veins running around the shell. Usually a black spot is an indication that the embryo has died when accompanied by a "ring" of blood around the middle or 1/2 of the egg. Those that are clear did not develop. Look very close though before you toss them. Somewhere there is an illustration of what to look for on the web. I'll check and be back......
When I candle the dark spot is the embryo with veins running from it... ... I don't know the answers to the other poultry questions..have never tried to incubate any of those... Clear eggs if shipped can mean the post office has scrambled them... or if your own chicken eggs they may not be fertile...to test fertility in your own chickens eggs you need to crack a few fresh ones open and look for the fertile white disc....
Guineas are 26-28 days. This is a quitter: http://lancaster.unl.edu/4h/Images/Embryology/images/Candling2002/April_8Quit.jpg This is a fertile egg: http://lancaster.unl.edu/4h/Images/Embryology/Photos/CandlingPhotos/CandlingDay7.jpg