The Last Savage (1978)
The horrors chronicled in Addio Ultimo Uomo (The Last Savage) include: vivid castration sequences - both male and female, animal snuff (including a dog being killed, skinned and roasted over an open fire), way out there rituals, African mud hut sex, self mutilation and body scarification which is compared to the craze for plastic surgery in the Western world and there is a lot of footage of a very dead, very rotten and very pungent man being prepared for burial.
