Perhaps it should have been ungulate sex?

Main Entry: ungulate
Function: noun
Etymology: New Latin Ungulata, from Late Latin, neuter plural of ungulatus
: a hoofed typically herbivorous quadruped mammal (as a ruminant, swine, camel, hippopotamus, horse, tapir, rhinoceros, elephant, or hyrax) of a polyphyletic group formerly considered a major mammalian taxon (Ungulata)