If the air sac is too large the humidity must be increased. Here's a very good article on humidity during incubation that explains it better than I can:

http://www.brinsea.com/customerservice/humidity.html

Good luck with your hatch!

Quote:

Originally Posted by pinky67 

Hi all! HELP! Need some advice! Incubating shipped silkie eggs...day 11. Nice veining and movement in all. Almost all have large saddle or partial saddle air cells. I have kept them upright and only started turning at day 7. I think the humidity was high the first week 60-65 (didn't have a hygrometer just followed Brinseas directions) Have a hygro now and have been running about 40 for the past few days. My question is should I increase or decrease the humidity because of the already large air cells? Or will it make no difference? Thanks so much for any input!!!

There is a massive thread on shipped eggs and their issues http://www.backyardchickens.com/t/704328/diary-notes-air-cell-detatched-shipped-eggs

My advice is to pose questions there. The experts lurk there and are more likely to see your questions. Good luck

Saddle shaped air cells are very common with shipped eggs and do appear larger in most cases.... they can hatch fine but you will want to mark that air cell with a pencil line and keep a close eye on it during lockdown....http://www.backyardchickens.com/a/hatching-eggs-101  this is a paste from the article and also refer to these page if necessary Guide to ASSISTED Hatching ~ Mushy Chick Disease

PIPPED the WRONG END

The normal hatching position is where the spine of the embryo runs parallel to the long axis of the egg and the beak is positioned underneath the right wing. The tip of the beak is directed towards the air cell in the blunt pole of the egg. When the beak is under the right wing, the wing holds the shell membrane away from the face of the embryo and thus gives the beak more freedom of movement. In addition, the wing helps stretch the inner shell membrane and helps the piercing of this membrane by the beak. In this way, the embryo gains access to the air cell of the egg and begins to ventilate its lungs.

Common reasons for increased incidences of Malpositions are:

Eggs are set with small end up. As part of a monitoring program, check eggs in the egg room or in the setters to ensure that eggs have been set correctly.

Advancing breeder hen age and shell quality problems.

Egg turning frequency and angle are not adequate. Proper frequency of turning through a 45 degree angle assists the embryo to position for hatch. The standard turning rate in the setter is 1 per hour.

Inadequate percent humidity loss of eggs in the setter. Acceptable weight loss of eggs from setting to transfer is 11-14%.

Inadequate air cell development, improper temperature and humidity regulation, and insufficient ventilation in the incubator or hatcher.

Imbalanced feeds, elevated levels of mycotoxins, and vitamin and mineral deficiencies.

Exposure to lower than recommended temperatures in the last stage of incubation.

Normal hatching position and the six recognised malpositions:
http://www.thepoultrysite.com/articles/1608/investigating-hatchery-practice-examining-the-hatch-debris

SHIPPED EGGS and SADDLE SHAPED AIR CELLS ~

(when one or both sides have a large "dip" in the air cell.)

Look at this position..... I alot of times with saddle shaped cells the chick doesnt position correct for hatching and alot of times the feet are in a bad place like stuck behind the head and actually smoosh the chick so they cant move, it can also force the yolk sack and everthing more north in the shell....

Look at the pics and note the top of the egg and how far down this air cell goes, alot of times they CAN do the internal pip but cannot hit that outer membrane/shell. This is why I mark the air cells and keep a close watch on them at hatch and if they seem "later" that the rest by about 6-12 hrs I will begin an assist by candle and tapping to make sure I have that internal pip, HOWEVER in this case you cant see the internal pip too well because of the angle, so I always tap to see if I hear them. and if I do hear a chirp then I follow the Assist steps... If not I check again in another 6 hours....and repeat...

When to assist?

Assisting a chick should be your LAST RESORT

PLEASE READ the following ARTICLE

BEFORE you try to assist a chick!

Step By Step Guide

to Assisted Hatching:

http://www.backyardchickens.com/a/step-by-step-guide-to-assisted-hatching

I think thats a good plan!

I have a sneaking suspicion that your air cells are just abnormal looking, not overly large. Shipped eggs frequently have wonky air cells but are still usually hatchable under the right conditions. I am a little concerned though that you did not have your eggs turning for the first 6 days, that could cause a problem. In the future it's best to leave the eggs sit upright (fat end up) for 24 hours and then set them (upright) in turners. You can then leave them incubating in the autoturners like normal. If you were doing them by hand (not autoturners) you could set them upright in an eggcarton and then put something under the side of the carton to "turn" them (so your eggs are tilted to one side). Do this a few times a day alternating sides.

60-65 % humidity is high so I'm glad you got it lowered. I would not go over 40 unless you truly are having huge air cells (not just misshapen). If it were me I would be dry hatching somewhere in the 25-30% humidity range and then increasing to 65% at lockdown

Good luck with your hatch! Silkies are ADORABLE!!!!

Trish