Here's why:
* Corpora lutea are normal structures in the ovaries of mammals. They form after ovulation, when the follicle that released the egg transforms into a yellow body.
* Pigs are mammals. Like all mammals, they undergo a menstrual cycle or an estrous cycle (depending on the species).
* The corpora lutea play a crucial role in reproduction. They produce progesterone, a hormone essential for maintaining pregnancy if fertilization occurs.
Therefore, it's completely normal to find corpora lutea on the ovaries of a pig.