Incubation Duration

[Guest]

Can someone verify that 21 days for incubation for chicks equates to 21 full 24 hour periods (set at 10 a.m on Saturday then they start hatching at 10 a.m on Saturday 3 weeks from then)?  This is my understanding of 21 days (504 hours of incubation time).

Or is it 21 calendar days (i.e. set on a Saturday and they start hatching on the Friday preceeding that third Saturday)?

I have been a lot more diligent in my record keeping this year and only set eggs each Saturday morning of the week\'s collected eggs.  My settings have all started pipping the day before (on the 20th day in my understanding).

I run my incubators with a pair of digital thermometers in each one and they alternate between 99 and 100 degrees at varying times for each one (so my conclusion is that it is running at 99.5 average).

Do I just have the oven too hot?

[bantamhill]

I personally run my incubator a little hot because I think a quicker delveloping chick is stronger than a slow one. I have many eggs hatch on day 20 (especially bantams). I would simply set them a day latter if you are wanting them to hatch on a specific day. If you set on Saturday at 10am . . . the end of the 21st day is Friday at 10am.

Michael

[Guest]

If you set on Saturday at 10am . . . the end of the 21st day is Friday at 10am.

Michael

I must be reading the calendar wrong.  Starting with the time of setting (for example, Sat. at 10 am), the 24 hour period from then to the next day constitutes 1 day.  So, on Sunday the next day at 10 am is 1 day, 10 am on Monday is 2 days, and so on until the third Friday at 10 am makes my count 20 days.

[Guest]

I\'m on my first incubation now with the machine holding 99.5 rock solid. I put my eggs in 3/2 at 10 PM, so I\'m projecting 3/23 at 10 PM as the hatch time. That\'s 21 days. I\'m using the 24 hour method, but that\'s as a guide.

I\'ll post here if any birds hatch sooner than that, which I understand may be up to 24 full hours.

[jwoodhaven]

Most of our bantams are hatched at day 20 and the large fowl are hatched by the end of the day on the 21 day. We keep our temps at 100 to 101 and find that we have a better hatch with the slightly higher temp. We also have the humidity at 60 to 65% durning incubation and 70-75% durning hatching.

[John]

I must be reading the calendar wrong

I don\'t think so.
I set eggs on Sunday evenings around 6pm and expect them to hatch 21 days later on a Sunday.  Some will start hatching a day or more early and some may be up to a day late.  I adjust the thermostats so that the chicks hatch as close to 21 days as possible and not to the thermometer readings.  Those that hatch a day early are generally much better survivors than any that hatch a day late.  The eggs from some breeding pens will hatch much sooner or later than others.
Day old chicks are supposed to be less than 24 hours old when you put them in the mail.  When I mail them on Monday afternoons I say they where hatched at 6pm the day before (Sunday).  Remember we are dealing with the government here and they require the date and time of hatch to be written on the box.  You and I know that all 25 chicks didn\'t hatch at the same time, but I know that theoretically that is the time they should of hatched based on the date and time I sat the eggs.  

[Guest]

I run my incubator at an average of 99.5 (my digital thermometers only display in full degrees and alternate from 99 to 100).  The incubator keeps around 55% humidity.

I set each hatch at 10 am each Saturday morning.  On the 18th day (Wed morning), I move the setting from my incubator over to my hatcher which I run at the same temp (99.5) with around 65% humidity.  During the move, I candle the eggs and toss the clear ones.

For three hatches in a row now this year, I see two to three eggs with the first pip marks on the 20th day that morning.  By that evening (20.5 days), 50% of the setting has already hatched.  I pull those chicks and put them in one of my brooders, removing the empty shells to clean up a bit.  

By next morning (Saturday at the 21 day mark), another 40-45% of the setting has hatched, leaving only a few straggler eggs.  These get pulled and moved to the brooder like before, with cleanup of emptys.

The remaining eggs I leave in the hatcher for the rest of Saturday and Sunday.  Any that are going to hatch have done so by Sunday morning (day 22).  Sunday evening, I candle the remaining eggs and decide then whether to cook them for another night or not (I\'m an optimist...grin).  

On Monday, I shutdown the hatcher, cleanup all the debris, wash it all down, disinfect, etc. and let it dry until Wed to start the process over again.

This seems to be working extremely well.  

[John]

Sounds like you are doing things right.
I do wait a little longer before moving eggs from the incubators to the hatchers though.  Generally I do it on the 19th day and sometimes have waited until an egg or two start to pip before moving them.

It seems according to one study, http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12762394&dopt=Abstract, that eggs that are stored for shorter periods hatch sooner than those that are stored longer before incubation.

[John]

Here is a site, http://muextension.missouri.edu/xplor/agguides/poultry/g08353.htm that has a couple interesting bits of info.

The normal incubation time of most chickens is 21 days to 21 days, 6 hours. Table 3 shows normal incubation times for other birds. Incubation time may vary according to temperature of weather and incubator, size of egg, fertility of egg and vigor of the embryo, and a host of other factors.

A one-half-degree change in average incubation temperature will move the average hatch time by about 5.4 hours.

[bantamhill]

 
It is apparent to me that I have been hatching chicks on day 20 for about 20 hatching seasons! I have never counted hours before and it appears that I am going to have to admit that I was incorrect in my counting and eat some proverbial \"crow\"! I normally set on Sunday and expect the chicks to hatch on Saturday . . .

Seriously, I think that the chicks that hatch earlier are more vigourous and do better in the long run.

Michael

[Guest]

My hatchlings this year are all strong and very healthy.  No problems whatsoever in my opinion.  From the 4 hatches so far this year, all have started hatching on day 20 and finished up on day 21.  Only one chick so far has hatched on day 22.

I put in new motors and added automatic humidity kits (pan w/ humidity pads, float valve, and the feeder tank) into my incubator and hatcher.  The combination of the two fixed my humidity problems I had last year.  I can adjust the humidity to pretty much however I want it to be with the addition/removal of the number of pads and opening/closing of fresh air vents.

This not only has made for healthier, stronger chicks but increased my hatches.

I agree with you that hatching a day early makes for stronger chicks.