Yep, semen collected using an AV (artificial vagina) is usually higher quality than that collected by electro-ejaculation, as well as being (arguably) better welfare for the bull. But, bulls have to be trained to mount the animal in the head bail (usually a steer, sometimes a spayed or infertile heifer). The electro-ejaculation is good for bulls who are too nervous/difficult to train to mount the teaser animal, or old or infirm bulls who cannot mount.
This is the AV - the small vial goes on one end to collect the semen, and a rubber lining goes inside the black casing. The rubber lining is filled with warm water (some bulls are particularly finicky about the temp they want their AV - you get used to each individual bull's needs over time). The little knob on the black outer casing can adjust the pressure inside the AV - again some bulls like it very tight and some prefer it a little looser. The AV is lubricated well and you are ready to collect.
Some bulls like to have a few false mounts before they get down to business; others do it straight away. Like I said, you get used to each bull's habits. Some collectors like to restrain the bull to make sure he has a couple of false mounts as it increases sperm count. Some collectors flush the bull's penis with water from a bucket/jug during these false mounts, to ensure clean semen.
As the bull mounts, the collector grabs the sheath of the bull and deviates the penis towards the AV; the bull thrusts into the AV (as opposed to putting the AV on the bull's penis). The warmth and pressure trigger the bull to ejaculate. In this pic there is a warming jacket on the AV around the collection vial, but we dont have that luxury and instead you hold the AV at that end with the vial in your hand to keep it warm.
I've collected bulls, rams and bucks and I gotta say I much prefer the small ruminants lol