Stuck soft-shelled egg Cornish Rock

[Allears]

What additives in the goslings feed are you afraid of?
If they're words difficult to pronounce, they're likely stabilized vitamins, minerals and amino acids.

Cornish Rocks are the result of a mating between a Cornish rooster and a Plymouth hen. Their genetics have been selected for rapid growth of the offspring which are only intended for meat since they usually develop health issues before they get on in age.
Corn is a good source of energy, which is why it is one of the main ingredients in most feeds. That said, it is a terrible source of essential amino acids, and most vitamins and minerals.
Feeding only corn basically starves them nutritionally over time.

These are my opinions. I know that people do grow them out and keep them for laying but often their quality of life isn't great.

I appreciate the input, thank you. If I see that they are struggling, or suffering at all, I will have them put to sleep.