I have seen several cows with these (fistulas) and actually, they don't mind at all. The animals with them also play a huge role in helping sick cows get better - explains the reason behind doing this.
The Jersey in the video was probably simply sick of being locked up without feed in front of her. Who knows how many takes they had to do to get that short video? The only cruel thing IMO is that she was separated in this video from any other cows and just wanted to get back to them - cows need their herd.
Cows are really hardy animals and can't be compared to people. For example, most bovine surgeries are done standing, they may use a sedative and will use something to block the surgical site, but the cow is awake. And they don't mind at all! They will happily just stand there eating or chewing their cud through out the whole thing - at least all the surgeries I've seen!
