Hatching Eggs of Different Breeds at Same Time

[SmithsCoop41]

You are right, they are all chicken eggs and it isn't necessarily the breed so much as the size of the egg. The breed notorious for early hatching is the Serama because they are so tiny at about 16 grams. Sebrights and silkies could be early as well. One reason is that when setting, the smaller the egg, the sooner the intside comes up to temperature. Sometimes, depending on the location of the egg in the incubator it can affect timing. If a small egg is in a hotter part of the incubator, it will be earlier. Even forced air incubators can have hotter and cooler spots. The best thing to do is change the location of all eggs in the incubator every few days.

What I really want you to do is stop stressing about the humidity. Let's simplify things for you. A mother hen, usually has good success rates. She doesn't own a hygrometer and she can't control changes in ambient humidity. If she is witnessing a thunderstorm, she is exposed to 90+% humidity. If it is arid, she could have ambient humidity around 20%. So how does she do it? First, except for frequent turning, she sits tight containing the humidity from all moisture loss. She also achieves an average humidity over the course of incubation. You should be aiming for the same thing.
You don't have to toss out an incubator that seems to have unsteady humidity as long as temperature control is good, even as a backup an incubator is a valuable thing to have on hand.
Until I finally got some extremely accurate hygrometers, I didn't even check humidity. Much more important than humidity at any one point during incubation is the egg weight loss throughout incubation. That is all that really matters. During the first 18 days of incubating chicken eggs, you are trying to achieve 11-13% weight loss. So regardless of egg size, breed or even species, you want to stay around 0.03% weight loss per day. I'm not sure if I did the math correctly but I think that comes out to about a 1.25 gram weight loss per day with a 40 gram egg - which is about what you have I imagine. What I did for many years was to use a pocket gram scale and weigh before setting and at weekly intervals with some water in the incubator. At week one, If they haven't lost enough weight, let it dry out. If they lost too much, add water and surface area. Surface area affects humidity, not volume.
If you have a larger scale, you can weigh a whole carton or flat of eggs and calculate the weight loss of the lot. However, some of the larger kitchen scales are notoriously inaccurate. Weigh the same egg 3 times in a row, if the scale shows the same reading each time, you are good to go.
This is a much more accurate way to increase success rate than constantly measuring humidity.
Then all you have to do at lockdown is to raise the humidity as much as you can unless you have condensation on the window, in which case you can lower it.
When hatching is imminent, a mother hen sits tight and doesn't move to retain humidity.

Lock down day is a made up number. You don't even have to worry about turning the last week so theoretically you can lock down any day the last week. That is because the first 10 days is the most critical for turning and you should turn as much as possible then. By the end of 2 weeks, the extra embryonic membranes (allantois, chorion and amniotic) which feed the embryo are well formed.

Thank u so much for all the information.

 

[SmithsCoop41]

You are right, they are all chicken eggs and it isn't necessarily the breed so much as the size of the egg. The breed notorious for early hatching is the Serama because they are so tiny at about 16 grams. Sebrights and silkies could be early as well. One reason is that when setting, the smaller the egg, the sooner the intside comes up to temperature. Sometimes, depending on the location of the egg in the incubator it can affect timing. If a small egg is in a hotter part of the incubator, it will be earlier. Even forced air incubators can have hotter and cooler spots. The best thing to do is change the location of all eggs in the incubator every few days.

What I really want you to do is stop stressing about the humidity. Let's simplify things for you. A mother hen, usually has good success rates. She doesn't own a hygrometer and she can't control changes in ambient humidity. If she is witnessing a thunderstorm, she is exposed to 90+% humidity. If it is arid, she could have ambient humidity around 20%. So how does she do it? First, except for frequent turning, she sits tight containing the humidity from all moisture loss. She also achieves an average humidity over the course of incubation. You should be aiming for the same thing.
You don't have to toss out an incubator that seems to have unsteady humidity as long as temperature control is good, even as a backup an incubator is a valuable thing to have on hand.
Until I finally got some extremely accurate hygrometers, I didn't even check humidity. Much more important than humidity at any one point during incubation is the egg weight loss throughout incubation. That is all that really matters. During the first 18 days of incubating chicken eggs, you are trying to achieve 11-13% weight loss. So regardless of egg size, breed or even species, you want to stay around 0.03% weight loss per day. I'm not sure if I did the math correctly but I think that comes out to about a 1.25 gram weight loss per day with a 40 gram egg - which is about what you have I imagine. What I did for many years was to use a pocket gram scale and weigh before setting and at weekly intervals with some water in the incubator. At week one, If they haven't lost enough weight, let it dry out. If they lost too much, add water and surface area. Surface area affects humidity, not volume.
If you have a larger scale, you can weigh a whole carton or flat of eggs and calculate the weight loss of the lot. However, some of the larger kitchen scales are notoriously inaccurate. Weigh the same egg 3 times in a row, if the scale shows the same reading each time, you are good to go.
This is a much more accurate way to increase success rate than constantly measuring humidity.
Then all you have to do at lockdown is to raise the humidity as much as you can unless you have condensation on the window, in which case you can lower it.
When hatching is imminent, a mother hen sits tight and doesn't move to retain humidity.

Lock down day is a made up number. You don't even have to worry about turning the last week so theoretically you can lock down any day the last week. That is because the first 10 days is the most critical for turning and you should turn as much as possible then. By the end of 2 weeks, the extra embryonic membranes (allantois, chorion and amniotic) which feed the embryo are well formed.

Thank you for all of the information. I appreciate it. I'm so anxious to see what all the babies are going to look like! I know they will be mixes, but that's okay too.