"In animals that failed to ovulate on their first cycle, follicles began to recede but were not fully reabsorbed and could be distinguished from a second batch of follicles based on their echogenicity""...
https://www.unboundmedicine.com/med...ing_hormonal_behavioural_and_physical_traits_
https://www.unboundmedicine.com/med...ing_hormonal_behavioural_and_physical_traits_