Penned Like Animals
From the 1972 movie Prime Cut. According to my source:
The movie was considered highly risqué for its time based on its violence and particularly its graphic depiction of female slavery, including a scene depicting naked young women in pens being auctioned like beef cattle.
Elsewhere on Bondage Blog:
Being auctioned like cattle isn’t the worst part.
It’s the being branded after the sale.
One of the slae girls is supposedly Sissy Spacek.