Under which ethical framework is it possible to justify industrial slaughtering of animals?

When you say "some people have different values" you probably mean "some people have simply not thought it through". I really don't think there's an ethical framework that favours industrial meat production. But please surprise me.

Now, most people have inconsistent ethics. Which I think is a different thing. I think most people that engage with the industrial meat complex simply ignore the ethical implications, that's actually quite easy to do and even more so when most people are just inconsistent when it comes to ethics. Sometimes people are utilitarians, other times they behave like deontologists and other times they will apply ethics of care.

I believe we are constantly building our own personal ethical frameworks. And that's kind of what you're alluding to, but I also think it's important to acknowledge that consistency is important, and I believe if we really tried to accomplish that most people would be faced with a very harsh reality. It's a struggle but we should be more honest with ourselves and the rest.

That's an interesting point. Some people might really need to supplement their diets with certain animal products, though as far as I know, a vegetarian diet or a diet that includes very little meat consumption is more than enough for most people in terms of health requirements.

Yet that's not really the case, we eat a lot of meat. And red meat as well which really is not necessary in our diets. I believe trying to argue from a naturalist perspective is rather dishonest in that it's by no means the real reason why people consume meat. People consume meat the way they do because it's a cultural expectation as well as a highly pleasurable act for most.

So really, to me, the dilemma has much more to do with how much pleasure are we willing to give up as a society and I really don't think that goes very far. I mean, this debate has also ramifications when it comes to the climate; how much are we willing to give up in comfort and pleasure to curtail the ecological disaster we are causing? The answer: not much really.

In my opinion these are really failings of our political systems, so in other words, the system that's supposed to help us make decisions for our society as a whole. I'm pretty sure most people would agree that maybe in a reasonable amount of time we'd like to see changes to our diets, it's an interesting discussion to have and there could be long term plans to achieve it that could be very much realistic... but our political system simply does not allow the for the discussion to be had in the first place.

Just to clarify because it’s not obvious in your comment (but not alluded to either): it is very much possible to opt out of animal cruelty for food and eat a vegan diet while being healthy.