Backyard Poultry Forum

i'm sure a lot of you have seen something similar in text books
but we're just posting this to show you an actuall egg,,not a drawing
goose egg clearly shows what we consider to be ideal development
day 28 was marked in the morning and is mid way down the egg
the photo was taken at dinner time and the next morning this guy was ready to go to the brooder
if the air sack gets any bigger than this hatch rate suffers, and of those you do get to pip some may need some knid of assistance( mainly keeping the membrain wet so that the young bird doesnt get stuck and can move inside the egg)
we aim for the same development with our duck eggs
this year i sacrificed some duck eggs,a previous season had shown us what was too much air sac development, i wanted to know just how little development you could get away with and still get a reasonable hatch rate, line 26, which is the first line to the right of where the gossling is pipping is about as wet as you could expect to get away with,,if the development is any less than this, the hatch rate is poor, most of the duckling with less development than at line 26 pipped but did not hatch
the very first ring is 7 days from hatching,,from day one through to 21 the air sac development is very slow.
from what i've noted, even running the bator at 90% humidity you can't slow down the development of the air sac of a healthy chick in the last few days.
when we first started incubating we plotted wieght loss graphs and tried to follow those, unfortunately this method doesnt seem to work to well as the eggs end up being to dry. this method of visually tracking the air sac would be our recomended way of doing it
good luck and happy hatching

here he is the next day in the brooder

and here is a couple of days old

I was reading about a gosling- but seeing a chicken- took me a moment to work out the gosling was in the marked egg starting to hatch. It can be very useful to mark the eggs- especially for someone starting out and wanting to monitor things more closely.

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Taylorducks
Breeder of Indian Runners

well we're not exactly starting out....lol...but we do monitor things very closely
we'll track atleast 2 eggs in every setting..
air sac development is also a good way of picking those that may have stopped developing (died) a keen eye will spot the blood vessels in the egg break down over a day or two. but if you havent spotted the break doen of the blood viens then the air sac shows you, if you've got some that are developing at a similar rate and a couple that appear to have stopped and havent done a thing for a day, inside the last 7 days, chances are the chick has died

knew we had a better photo hiding somewhere.
same egg, pic taken a few hours before the one above, pencil is pionting to where gossling has just started pipping

That is excellent info. Great thread!!

I'd love to have two incubators so I could run them at different humidity levels and swap eggs between them according to whether they need speeding up or slowing down re. air cell development. As it is I just have one but I set eggs from the one duck only so I know they all have the same porosity and can be treated the same. With my first hatch I had eggs from three different ducks and they differed hugely in shell porosity and therefore air cell size. Had almost zero hatch from ones with small air cells (1 out of 10 and it had help too).

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Cheerio, Rach
Blue Swedish Ducks

Hi I am a first time incubator. I have duck eggs. I had humidity set at 55-65% and am worried air sac is too small at day 17. I have since lowered humidity by taking water out of well and added a silica pack. This is day 21 each picture is different egg please tell me if they look ok and if there is anything more I can do to help if not.

Someone more experienced may comment on the air sac development, but not sure lowering the humidity is the way to go.

Scroll down this thread on humidity to see RnBs Waterfowl's humidity settings viewtopic.php?f=16&t=8009924&p=550155&hilit=duck+eggs+humidity#p550155

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John

They look ok for day 21. Still a week to go. The air sac development does accelerate towards the end. I'd leave humidity at around 55 for now. I don't think you're too far off track, if at all.

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Cheerio, Rach
Blue Swedish Ducks