Being no expert in the field at all, I’ll post links that seem to contradict each other. In some circles, people seem to agree that basically all bodily fluids are either blood or a filtered derivative of blood. Others say this is not the case…

https://youtube.com/watch?v=NcsGpDFKCgY

https://www.chefsresource.com/is-milk-filtered-blood/

And those that say eggs are chicken periods aren’t quite correct, but it definitely relates to their reproductive cycle…

https://chickenguides.com/eggs-are-chicken-periods/