As a little project for myself, I decided to add a few light-colored eggs to my incubator simply to candle and photograph each day. Not only will this be fun, but it serves a purpose for me as well.
Brinsea recently brought attention to research pointing towards periods of cooling and air exchange – such as would naturally occur when a mother hen gets off the nest to eat and relieve herself – which increase hatch rates and vitality of chicks. With an automatic turner, there is rarely a reason to open the incubator, yet opening the incubator for candling or egg turning can actually be beneficial. Thus, it is recommended that styrofoam incubators are opened to allow a complete air exchange at least once a day. I can pursue my little project and provide an air exchange at the same time! Although the research points to benefits from ten minutes of cooling, my candling lasts only a minute or two.
There are dangers to candling. The oils and bacteria on your hands can clog and infect the pores in the egg’s shell. The jostling from being lifted, handled, and laid down can damage blood vessels and other delicate structures. Not only that, people sometimes drop eggs as they candle, even dropping them onto other eggs still sitting in the incubator. Candling is risky. In my hatch calendar and candling guide, I recommend candling on only days 7 and 14 for exactly this reason.
I added several light-colored eggs from my flock that I can live with losing so that I can indulge in a few photographs. This post includes the first four days of incubation, corresponding to my Basque Hen hatch, counting down in the right-hand column.
As a side-note, it seems that the same development seen here on the top of eggs held upright in the turner occurs on the side of eggs laid on their side for incubation. I noted this for the first time candling this evening. I flipped the eggs to their other side and will see tomorrow if the growth actually moves from what is now the bottom to the top side of the egg. Hmm. So much to learn!