I did check with my book on vitamin deficiencies in eggs and embryos, and most of the time they do not make it past day 20 in the incubation. This mean they should not make it to term in the first place.
Vitamin A + E deficiencies can make it to term, but do not cause deformities. They are linked to respiratory and circulatory problems.
Vitamin D deficiencies can also make it to term, but you end up with soft rubber type bones and not deformities.
The hole vitamin B group (including niacin) deficiencies are related to bone deformities and neurological issues, and do result in death before day 20.
Freak deformities to one leg, one wing or neck can happen due to wrong position inside of the egg, or lack of egg turning. They are very rare and should never happen to two eggs in the same hatch.
See that put it back to genetics.
Lets see what happens to the rest of the eggs. If you end up with another one than that is enough proof to the genetic question.
Vitamin A + E deficiencies can make it to term, but do not cause deformities. They are linked to respiratory and circulatory problems.
Vitamin D deficiencies can also make it to term, but you end up with soft rubber type bones and not deformities.
The hole vitamin B group (including niacin) deficiencies are related to bone deformities and neurological issues, and do result in death before day 20.
Freak deformities to one leg, one wing or neck can happen due to wrong position inside of the egg, or lack of egg turning. They are very rare and should never happen to two eggs in the same hatch.
See that put it back to genetics.
Lets see what happens to the rest of the eggs. If you end up with another one than that is enough proof to the genetic question.