zootube365 seems to be the most popular
animal sex (dog fuck, bestiality porn, horse sex) video site.
And it uses HTTP .flv streams for the animal porn/sex videos so it is very easy to
record videos streams from zootube365.com.
By the way I use
Replay Media Catcher 4 for downloading/capturing sex videos from adult video sharing web-sites. And in some cases I just record sex videos from screen with
Replay Video Capture. But you can use any
streaming video recorder that you like instead.