Bad hatch rate: incubating in the summer heat? Or humidity is wrong?

[suburbanfarm]

Room humidity isn't going to be the same humdity in the incubator. You need to know the humidity in the incubator.

If you take the same air and heat it up, the relative humidty is different. Looking at the chart, say your room temp is 70 F and RH is 75% the dew point is 61. Now find dew point of 61 at 100 F, the relative humidity is ~28%.

The rooms humidity and temperature does play a role in the incubators humidity because that is what is being pulled into the incubator through the vent. That is why some people can "dry incubate" and some can not. If your rooms RH is fluctuating badly then the incubators RH will fluctuate too such as with an air conditioner.

If you want to really know what humidity to run in your incubator, then weighing the eggs is the key. You can get a gram scale at walmart or harbor fright.

Thanks, yes measuring in incubator via hygrometer that I've calibrated. Was just mentioning humidity in the house is quite high as context. Thanks for the chart, so much to learn when incubating!

Last time I drew air cell progress and it seemed to follow nicely along the diagrams I'd seen. But I would be interested in weighing eggs, it seems possibly more precise.

I already have a scale that's very accurate for making diy capsules of herbs etc. I would like to learn more about the weighing strategy. I already number eggs etc.

 

[suburbanfarm]

Where these your eggs or did you buy them? If you bought them were they shipped? Shipping can adversely affect the hatchability of the eggs even those that make it to lockdown.

The age of the birds can also affect the hatchability of the eggs. I just hatched some of our pullet's eggs and 2 out of the 5 didn't make it. They were fine at lockdown, but there's quite a process for the chick to transition to breathing for itself and some just don't make it. My other girls are much older, between 5-7 years of age and I ended up with 14 chicks out of 21 eggs set (3 of them weren't fertile).

I dry incubated because my eggs were all very fresh. If the eggs were older and had already started to lose moisture I would have raised the humidity to around 35%.

Definitely calibrate your thermometer as temperature is the critical component. Slightly too low and the eggs struggle to lose sufficient moisture.

Your lockdown humidity was fine in my opinion.

Thanks. Eggs purchased locally. So I don't know the details on age of eggs, age of the girls laying, how long they were sitting out before they were collected, what temperature they were stored at, etc etc.

Our aim is to have our own supply of eggs for the incubator, but our girls aren't laying yet. The people we're buying eggs off are all lovely people, but there's just so many variables were can't control.

We started with quite a big batch. I'd say about one-fifth not fertile, one-fifth early quitter, one-fifth late quitter, one-fifth fail to hatch, and one fifth hatch.

It's been super hot weather here and I'm told that generally the serious breeders simply don't hatch in this weather (Australia). So I'm not really sure if I'm doing something wrong, or if this is just the tough nature of hot weather....

Definitely looking forward to calibrating my thermometers so that I can be totally sure on that. But incubator and multiple thermometers were all saying same thing so I thought it was ok.

I was incubating at 37.8, but just realising maybe I should be dropping to 37.5 for lockdown.

 

[JaeG]

Thanks. Eggs purchased locally. So I don't know the details on age of eggs, age of the girls laying, how long they were sitting out before they were collected, what temperature they were stored at, etc etc.

Our aim is to have our own supply of eggs for the incubator, but our girls aren't laying yet. The people we're buying eggs off are all lovely people, but there's just so many variables were can't control.

We started with quite a big batch. I'd say about one-fifth not fertile, one-fifth early quitter, one-fifth late quitter, one-fifth fail to hatch, and one fifth hatch.

It's been super hot weather here and I'm told that generally the serious breeders simply don't hatch in this weather (Australia). So I'm not really sure if I'm doing something wrong, or if this is just the tough nature of hot weather....

Definitely looking forward to calibrating my thermometers so that I can be totally sure on that. But incubator and multiple thermometers were all saying same thing so I thought it was ok.

I was incubating at 37.8, but just realising maybe I should be dropping to 37.5 for lockdown.

I'm wondering if the very hot weather was affecting the hens as well - perhaps they weren't producing top quality eggs due to a bit of heat stress. It is hard to know from that perspective for sure.

It does take a few tries to get a feel for your incubator and what works in your climate too. Hopefully your next hatch will be more successful and I hope your girls start giving you some eggs soon. I'm in New Zealand and I'm waiting impatiently for my Araucana to start laying. We hatched them in September so hopefully in the next month or so I'll see some pretty blue eggs.

With weighing the eggs you can work out the average weight (weigh all of them together then divide by how many eggs) and track them that way. I make a simple line graph with days along the bottom and the weight range I'll need up the side. Plot the first weigh-in on day zero.

Eggs need to lose 12-16% of their start weight by day 18 so pick which percentage you want to go with (less for older eggs, more for fresh eggs, in the middle if you have a few of each) to work out how many grams they need to lose (there are handy percentage calculators online if you aren't mathematically inclined). Take that number away from the start weight, then plot that on day 18 of your graph. Draw a straight line from the point on day zero to the point on day 18. Then on any day you can reweigh them and see if they are near that line or whether you need to adjust your humidity.

It sounds more complicated than it is.

By using the average it doesn't matter if you have to remove eggs due to them not being fertile or quitting.

Hope the heat eases up for you soon. We've been getting the large highs coming down from Aussie here, but then we've had a few Antarctic blasts of cold weather so it's been a very strange summer, especially for those down south with record breaking temperatures one day then snow on the mountains the next! Crazy!

 

[suburbanfarm]

I'm wondering if the very hot weather was affecting the hens as well - perhaps they weren't producing top quality eggs due to a bit of heat stress. It is hard to know from that perspective for sure.

It does take a few tries to get a feel for your incubator and what works in your climate too. Hopefully your next hatch will be more successful and I hope your girls start giving you some eggs soon. I'm in New Zealand and I'm waiting impatiently for my Araucana to start laying. We hatched them in September so hopefully in the next month or so I'll see some pretty blue eggs.

With weighing the eggs you can work out the average weight (weigh all of them together then divide by how many eggs) and track them that way. I make a simple line graph with days along the bottom and the weight range I'll need up the side. Plot the first weigh-in on day zero.

Eggs need to lose 12-16% of their start weight by day 18 so pick which percentage you want to go with (less for older eggs, more for fresh eggs, in the middle if you have a few of each) to work out how many grams they need to lose (there are handy percentage calculators online if you aren't mathematically inclined). Take that number away from the start weight, then plot that on day 18 of your graph. Draw a straight line from the point on day zero to the point on day 18. Then on any day you can reweigh them and see if they are near that line or whether you need to adjust your humidity.

It sounds more complicated than it is.

By using the average it doesn't matter if you have to remove eggs due to them not being fertile or quitting.

Hope the heat eases up for you soon. We've been getting the large highs coming down from Aussie here, but then we've had a few Antarctic blasts of cold weather so it's been a very strange summer, especially for those down south with record breaking temperatures one day then snow on the mountains the next! Crazy!

That's great, I'll try that.

So I'll just do each breed separately then, hey?