Cow hoof shaving/popping. There are a few channels, but my favorite is "Nate the Hoof Guy," he's from Wisconsin and he just travels around to different games as a cow vet and helps trim their hooves. Sometimes it can get disgusting, but it's also fascinating to watch, and he's really gentle and loving with all the animals.
This was a guilty pleasure of mine as well for a long time but it started making my feed too fucking weird to the point where I was nervous about even loading YouTube in front of other people.