The claim is that artificial insemination isn't bestiality because milk cows don't struggle during the process, or that yes, it is bestiality, but it's ok in this context.
There's really only one way to get it. Use your imagination. Holding a "receptacle" doesn't help If someone told you the story about how they were holding a paper towel so their dog didn't get on your carpet, would it be any different? You not being sexually aroused doesn't help. Forcible insertion with an object for your own enjoyment in any other context isn't ethical. Why does it matter here? You're still abusing an animal to its own detriment.
That doesn't matter. Not going to get graphic here, but it didn't matter in the case involved in this wikipedia article, for instance. Regardless of what you want to label it, we would consider it unethical.
Why, following the above-mentioned case, did the law that made it a felony include the text "Nothing in this section prohibits accepted animal husbandry practices"? It's not like laws about driving stolen cars need to mention "by the way, just so you know, stolen-car laws don't apply to legally acquired vehicles". If this is so distant in practice, why is there such an overlap that this clause is needed to clarify any confusion?
It's still wrong because breeding cows to be slaughtered is harmful to animals, other people, and the environment. So you can kick these terms around all day, whether you want to call it bestiality or not, but what you call it doesn't change the core issue.