On a more plausible view of animal deaths than the one I discussed in the previous post, animal deaths are bad, but not as bad as the deaths of humans. Perhaps the badness of death corresponds to the complexity of certain psychological characteristics, or the capacity for happiness or fulfillment. Different people might cash out the view in different ways, depending on other philosophical commitments. I imagine something of this is a relatively common view. However, I think the implications of it are often misunderstood.
One might think that if killing a chicken is significantly less bad than killing a person, it might be permissible to eat a chicken. But when we think about killing a person, we tend to consider it one of the worst possible things you could do to a person (short of making them wish they were dead.) So even if killing a chicken is 1/100th as bad as killing a person, it might still be a pretty bad thing to do. I'm not really sure how to measure these types of things, but imagine breaking your arm is 1/100th as bad as killing you. It still would take a lot to justify breaking your arm, and the mere pleasure of a single meal would not cut it. And if I were responsible for the deaths of 100 chickens over say, 5 years, through all my consumption of flesh and eggs, etc., I would be blameworthy for the equivalent of one fully thought-out human murder every 5 years, which is pretty condemnable.
I don't really ascribe to this view, because I think there's not a strict covariance between wrongness and badness. It might be less bad if a sullen and removed human dies rather than a wonderful philanthropist who thoroughly enjoys life, but it is just as wrong for me to kill either. Likewise, I must not kill a typically functioning person or a severely disabled one for identical moral reasons. This doesn't go to showing equal culpability, which is a much more complicated question, but it does suggest that killing an animal might be on a par with killing a human in terms of wrongness. Which is a statement many people find wildly implausible, but most people are speciesist, so this shouldn't be surprising.
But, as is becoming a theme, you need not agree with me fully to accept the imperative of veganism. You could accept the view I described at the beginning of this post, and hopefully realize that this view implies that you ought to remove yourself from the animal exploitation industry.
Another implication of this view is that it leaves open the possibility of sentient alien beings who have developed to an extent such that their deaths are much worse than ours. They might then come here, see us, and feel the right to use us as property, because their lives are so much more valuable (this has been a common argument against anthropocentrism.) If we find this implausible, and think that they would have decisive reasons to treat us with respect for our lives, then we must extend the same consideration to non-human animals.