Minecraft wiki entry for Breedable, associated text:  Age: Represents the age of the mob in ticks; when negative, the mob is a baby. When 0 or above, the mob is an adult. When above 0, represents the number of ticks before this mob can breed again.
 ForcedAge: A value of age assigned to this mob when it grows up. Incremented when a baby mob is fed.
 InLove: Number of ticks until the mob loses its breeding hearts and stops searching for a mate. 0 when not searching for a mate.
 LoveCause: The UUID of the entity that caused this animal to breed, stored as four integers.