High rateof breech, Causes?

[GardenDmpls]

Just finished our third annual hatch in our high school animal science program. Upon doing an "eggtopsy" on the ones which didn't make it , one third of the eighteen eggs set in the incubator had chicks which died in the last few days before hatch because of mal-position. They all had their tails toward the air cell and five had not absorbed their yolk sack. The sixth had, and its egg had been rocking around until hatch day. My students want to know if we are doing something wrong. Is it a problem with the shipping, the incubator, the parent stock or is it just the breaks. Last year, we had a better hatch, but four were backwards and didn't make it out and another two were in poor position, but were helped and made it out ok. They were from the same hatchery as this year's eggs.

 

[GardenDmpls]

BUMP

 

[AmyLynn2374]

Just finished our third annual hatch in our high school animal science program. Upon doing an "eggtopsy" on the ones which didn't make it , one third of the eighteen eggs set in the incubator had chicks which died in the last few days before hatch because of mal-position. They all had their tails toward the air cell and five had not absorbed their yolk sack. The sixth had, and its egg had been rocking around until hatch day. My students want to know if we are doing something wrong. Is it a problem with the shipping, the incubator, the parent stock or is it just the breaks. Last year, we had a better hatch, but four were backwards and didn't make it out and another two were in poor position, but were helped and made it out ok. They were from the same hatchery as this year's eggs.

Common reasons of Malpositions are:
Eggs are set with small end up.
Advancing breeder hen age and shell quality problems.
Egg turning frequency and angle are not adequate.
Inadequate % humidity loss of eggs in the setter.
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.
Lower than recommended temperatures in the last stage of incubation.​

(From our assisted hatching thread.)

My first questions would be: Has the thermometers/hygrometers ever been checked for accuracy? What kind of incubator are you using, and is it still or forced air? What are your temps during incubation? What is your humidity during incubation first 17 days and what is your humidity for lockdown? Are the eggs being turned at least 3 times a day?

 

[GardenDmpls]

Thanks for your answer, and the questions too. The incubator we use is a Turn-X (forced air) with an automatic turner. There are two thermometers to monitor the humidity. We maintain a 99.5 degree temperature throughout and a humidity of between 58-65%, raising it to 80-82% the last three days. The eggs are candled on the 7th, 14th and 18th day (before removing the turner). The air cells are where they need to be. I suspect the thermometer might be a degree off, as all three hatches were on the 22nd and 1/2 day. (I set this last one on a Tuesday afternoon and the first hatched on a Wednesday morning, instead of Monday).

I am thinking that although I set them in the incubator with the large end up, during the turning (once an hour) they get to lying pretty flat. Also, some of the eggs I get are so rounded at both ends, it takes some thought to figure which end is bigger. I am thinking of trying to improvise some way to keep the air cell end higher up, perhaps add a metal or plastic ring that would fit under the eggs around the outside of the circular mesh they rest on. I can't get too experimental, as the students would be extremely disappointed if nothing hatched.

I pay for the eggs and get to take home the chicks at the end of the year. We have a very large coop and pen with plenty of room. We are currently letting our broody hen sit on a dozen eggs we got from a different source than the school eggs, as we've corrupted several of our neighbors (and brought some income to a out of work friend) into building their own coops and now they need chickens.

 

[AmyLynn2374]

Thanks for your answer, and the questions too. The incubator we use is a Turn-X (forced air) with an automatic turner. There are two thermometers to monitor the humidity. We maintain a 99.5 degree temperature throughout and a humidity of between 58-65%, raising it to 80-82% the last three days. The eggs are candled on the 7th, 14th and 18th day (before removing the turner). The air cells are where they need to be. I suspect the thermometer might be a degree off, as all three hatches were on the 22nd and 1/2 day. (I set this last one on a Tuesday afternoon and the first hatched on a Wednesday morning, instead of Monday).

I am thinking that although I set them in the incubator with the large end up, during the turning (once an hour) they get to lying pretty flat. Also, some of the eggs I get are so rounded at both ends, it takes some thought to figure which end is bigger. I am thinking of trying to improvise some way to keep the air cell end higher up, perhaps add a metal or plastic ring that would fit under the eggs around the outside of the circular mesh they rest on. I can't get too experimental, as the students would be extremely disappointed if nothing hatched.

I pay for the eggs and get to take home the chicks at the end of the year. We have a very large coop and pen with plenty of room. We are currently letting our broody hen sit on a dozen eggs we got from a different source than the school eggs, as we've corrupted several of our neighbors (and brought some income to a out of work friend) into building their own coops and now they need chickens.

The only thing that you are doing that I would do differently is the humidity. (I'm a low humidity incubation fan, anything over 45% makes me nervous). You said that your air cells were a good size, and that is good, but there are other issues excessive humidity can cause that could contribute to maleposition and size that would make it hard for the chick to turn. Many people, (I have used both) lay eggs on their side to hand turn them and have just as successful hatches as eggs that are upright during turning. My last hatch I hand turned with the eggs laying on their sides and had 33/36 hatch with only one that had problems at hatch (due to premature hatching.)

If it were me, I would try the low incubation humidity method (or at least a lower humidity than 58-65%, at least knock it down to 40-45%) and see if you fair better with a lower humidity. The method I use is in the link in my signature. I swear by it for the styro bators and I know it works well in the chineese plastic bators. I know a few people that use the Brinsea that fair well with humidity levels at 40-45% I only know one person that claims to have good hatches at a humidity levels as high as you are using. (Not saying there aren't more, just that I don't know any.)

That's my thought on it.

 

[lazy gardener]

Humidity too high can result in chicks growing too big, then they can't reposition. I also wonder if too much protein in the hen's diet can result in a chick that grows too big to be able to position correctly for hatch.

 

[GardenDmpls]

Thank you. I had read about a lower humidity to start, but was afraid to try it. Will file away the info for next year. Although I prop the eggs up slightly when I put them in the incubator, after the first turn, they lie flat. I wonder if that also prevents them from turning the right way.

 

[AmyLynn2374]

Thank you. I had read about a lower humidity to start, but was afraid to try it. Will file away the info for next year. Although I prop the eggs up slightly when I put them in the incubator, after the first turn, they lie flat. I wonder if that also prevents them from turning the right way.

I have awesome results with the lower humidity methods. A lot of people that have had dissapointing hatches have switched to the low humidity methods with great success. If the eggs are still being turned, laying down shouldn't be an issue. Unless, when they are getting displaced they aren't getting turned or turned the right amount, then flat is fine.