Then demonstrate that you are capable of it.
The stuff about the Cult of Artemis at Brauron was really a subtopic of anthropology. You don't seem to have very much capacity for talking about that, either. That was an odd little tangent I had, but it felt like it might tie in at the time. It is a little bit odd that humans would have empathy for animals at all, much less sexual attraction toward them, but it makes a lot more sense if you take into account how harsh Ice Age winters would have been on nearly bald apes that were attempting to survive in the Holarctic region. One would have had a difficult time convincing them that they did not like sleeping under several layers of animal skins in the name of any philosophy whatsoever, for one thing. For another, associating the sight of an animal with warm, fuzzy feelings (oxytocin) would have served as a highly effective reminder to them that perhaps they should attempt to obtain one. In an age where we it is not necessary for us to survive an Ice Age winter, we are left with the oxytocin rush that we associate with the sight of a cute furry animal, and in our comfortable and privileged time, we would frankly rather save it and perhaps keep one of them as a pet. Therefore, I could argue that veganism might actually, quite ironically, be related to an Ice Age hunting and tracking strategy: getting warm and fuzzy feelings at the sight of fur actually would have been highly effective at goading our ancestors into realizing that they were actually highly tired of being extremely cold, and once they were buried under the skins of those animals, they would have felt a lot better.
You don't seem to care much for anthropological tangents, though. You probably think that "The Cult of Artemis at Brauron" is something I got off of a roleplaying game. That's not entirely your fault. Ancient Attican religious beliefs is a fairly specialized niche subject to be interested in. I can recite multiple lines of the Iliad in perfectly enunciated ancient Attican Greek (I actually do shift the vowels to get the accent right), so I am most likely a lot more interested in that than most.
You missed an opportunity to rebut
@Tailo's argument based on a utilitarian approach.
Under utilitarian ethics, it would only be necessary to avoid causing the animal unhappiness, and by extension, the humane slaughter of cattle only affects the cattle, who are most likely not capable of any sophisticated abstract understanding of their mortality, by sparing them of the unpleasantness of old age. Humane slaughter is probably substantially less stressful to them than getting their shots. In the long-run, the cattle would have had very well cared for lives. From their point-of-view, it's probably a good deal.
However,
@Tailo could counter-attack by pointing out that we could apply the same logic to killing humans humanely, at the prime of their lives.
On the other hand, you could beat that by accusing him of making a false equivalence between humans and cattle. Humans actually do comprehend their own mortality, and they care quite a lot about living for as long as they are capable of living. Cattle, as far as anyone can tell, are pretty short-sighted and narrow-minded: their valences tend to revolve around seeing how fat they can get. Assuming that the animals can fully understand their mortality, in any abstract sense, is giving them too much credit.
Of course, this would not stop
@Tailo from pointing out how convenient it is that you assume, without a whit of proof, that cattle are truly not capable of comprehending their mortality. Has anybody bothered to try teaching it to them?
You could go around and around on this track for weeks and get yourselves some pretty lively exercise out of it, just as long as neither of you took anything personally. Once personal frustration gets into the mix, it stops being philosophy and starts being a piss fight. You are presumably two grown men, though, and there is no reason why we ought to assume that it would come to that.
Either you understood that, or you did not.