Today is Day 18, and so, in preparation for the coming hatch, I had to “lockdown” the eggs in the incubator. In lockdown, or “confinement,” the humidity increased, the automatic turner is removed, and eggs placed in their final position for hatch.
Humidity throughout incubation varies by method. In all cases, humidity is lower during the first 18 days of incubation and increased for the three-day lockdown period preceding hatch, the extra moisture allowing the chick to move more easily within the egg. Conventionally, humidity is maintained at about 50% during incubation and raised to 75% for hatch. With the dry hatch method, humidity is maintained at 20-35% throughout incubation and raised to 55-65% or higher during lockdown. I am using the dry hatch method. My humidity was about 32% for the first 7 days. Upon weighing the eggs, I found that my weight loss was high and raised my humidity second and third weeks of incubation, theoretically anyway: My week 2 and 3 humidity varied widely with extremes of 21% and 48%, averaging 37%. For 11-15% total weight loss, my eggs should have lost 9.43-12.86% by Day 18; my eggs have lost an average of 16.79% with a high of 21.05% and a low of 10.53%. So, we’ll see if there is any relationship between percentage of weight lost and hatch. Anyhow, I am aiming for 60% during lockdown, knowing from experience that humidity will increase as chicks begin to hatch.
The automatic turner can crush hatching chicks and needs to be removed before any chance of hatch. However, after removing the turner, the eggs are sitting lower in the incubator and are in a cooler temperature zone. Therefore, you need to lift the eggs to the same level they experienced in the turner. This can be accomplished in several ways. The floor of the incubator can be raised or the eggs can be place in or propped up in egg cartons. If the floor is raised, generally eggs are laid on their side. During hatch, eggs can be kicked around, and if the pip is turned down towards the floor, the hatching chick can suffocate. If they are too bound by an egg carton, however, a chick pipping too low on the egg or on the wrong end can pip into the side of the carton and suffocate. So, of course, one looks for a medium which provides support and air around the egg. During my first hatch, I leaned eggs on cartons cut down to only the sides. However, it was not enough support, and the eggs were kicked around like soccer balls by the early hatchers! Some even were kicked into the half-shells of previously hatched eggs, creating a second layer covering their pip! To provide more support, I am using cartons with the bottoms and high middle sections cut out.
During my last hatch, I had my first pip on the afternoon of Day 19 and the first chick was out the morning of Day 20! But that was an Easter Egger, which are known for early hatching, and these are Ameraucanas, which are known for late hatching. So, we’ll see. Either way, won’t be long now!