BlacksheepCardigans
Songster
Quote:
That's, unfortunately, the way most people think of eggs - as eggs. Not chicks. Think of an egg in lockdown as a chick in a box. It's respiring just as much, and consuming just as much oxygen, as it will in a couple hours when it hatches. They don't hatch and then start breathing; they were "breathing" all along. They were just doing it by absorbing oxygen through the shell. So they need lots of fresh air throughout the entire last few days of incubation.
The big commercial incubators pipe in air, always. The eggs and chicks don't rely on what's already in there. I don't know how the hatchery of your youth had their incubators set, but the big ones now will strictly control the CO2 level and they want it at .03% - which is the same as fresh air - at all times. Their alarms go off and dampers open when it gets much above that. There are a very few of them that allow CO2 to rise for one very brief period during hatching to force all the chicks to pip at once, but most keep it at fresh air during the whole hatch.
Because there's no such thing as a $6 CO2 monitor, and because people think of eggs as objects that turn into chicks rather than as live chicks in boxes, they get focused on humidity as the magic thing that gives you good hatches when in fact ventilation is much more important. Think about what a commercial egg goes through - on day 18 they go down conveyor belts, they're sorted, they get holes poked in them (so they're actually pre-pipped, out in room air with no extra humidity) and then they get put in a hatcher and are expected to hatch over 90%. It's not that humidity is meaningless - very obviously it's not. But it doesn't trump everything. And if you're losing a ton of pipped eggs it's not that your humidity was 60% and it should have been 65%, or that it was 72% and should have been 65%. It's much more likely to be poor air circulation.
That's, unfortunately, the way most people think of eggs - as eggs. Not chicks. Think of an egg in lockdown as a chick in a box. It's respiring just as much, and consuming just as much oxygen, as it will in a couple hours when it hatches. They don't hatch and then start breathing; they were "breathing" all along. They were just doing it by absorbing oxygen through the shell. So they need lots of fresh air throughout the entire last few days of incubation.
The big commercial incubators pipe in air, always. The eggs and chicks don't rely on what's already in there. I don't know how the hatchery of your youth had their incubators set, but the big ones now will strictly control the CO2 level and they want it at .03% - which is the same as fresh air - at all times. Their alarms go off and dampers open when it gets much above that. There are a very few of them that allow CO2 to rise for one very brief period during hatching to force all the chicks to pip at once, but most keep it at fresh air during the whole hatch.
Because there's no such thing as a $6 CO2 monitor, and because people think of eggs as objects that turn into chicks rather than as live chicks in boxes, they get focused on humidity as the magic thing that gives you good hatches when in fact ventilation is much more important. Think about what a commercial egg goes through - on day 18 they go down conveyor belts, they're sorted, they get holes poked in them (so they're actually pre-pipped, out in room air with no extra humidity) and then they get put in a hatcher and are expected to hatch over 90%. It's not that humidity is meaningless - very obviously it's not. But it doesn't trump everything. And if you're losing a ton of pipped eggs it's not that your humidity was 60% and it should have been 65%, or that it was 72% and should have been 65%. It's much more likely to be poor air circulation.
