Ahh..just realized that we were talking past eachother. I've never seen a spey surgery done!!
I'm just referring to spey blades to cut testicles...
I've done my share of cutting. We don't treat it as a major surgery at all. Slice a piece of the scrotum off the bottom. Pull one testicles out at a time. Pull, pinch, and strip the membraines back. Squirt disinfectant into the wound..... send them on their way.
The rancher we go to roundup at, tends to try and band the calves...but most years that's not always possible. It is usually the calves that drop early, and are significantly bigger that have to be cut. They are too big for the small bands, and too small for the full size bands. We had "midsized" bands and tools, and they did not work either.
I think I've probably cut 30 or so calves in the past few years helping out....and I was only one of 5 or 6 cutting.
We do try to band rather than cut. But some years the roundup does not happen until the some of calves are too big to band, but still way to small for the adult bands.
Surprisingly..... they did not give me much in the way of "training".... watch two, then do a few with them watching giving instructions. Then have me show others.
There were vets present......they did no cutting. But were taking photos!
I have looked at some with "humps!!" The protrusion it affords might make it easier to grab the right blade in an admitted "stressful situation!!"
Speying is a stressful time!!

Maybe someone who actually performs this "operation" could chime in!!
That's a major surgery and not done with a pocket knife, in fact is never really done with cattle.
It is not as stressful as you would think. But I've been kicked, knocked back, and generally roughed up when the person holding the calf does not do their job. I've been kicked square in the nuts while attempting the cut, which kinda seems fitting.
I've not cut my self badly ever, but have poked my hand a bit. I have used clip point, drop point, warncliff, spear, and spey blades. I've also used a scalpel, which was less effective for me. (The blade was too small to do the cut of the scrotum in one clean cut.
I've also found the calves seem to react to the cutting and nut removal less than to the branding.
We also inject and tag the ears at the same time.