Well it's good to see so much support, but I have to say that this value being placed upon "intelligence" makes me uncomfortable. Even the "less than intelligent" do not deserve what these animals are forced to endure. Do you apply this thinking to human beings as well?
I also hope that we will not suddenly venture down the dark road of utilitarianism and suddenly claim that these animal's rights should be taken away only if they're being tested on in a laboratory.
Well, people have different thresholds for stuff. While I respect and understand others' thresholds, mine might differ. Personally, I do value intelligence as a criterion. I think a line must be drawn somewhere. If we were to consider 100% of the animal kingdom forbidden territory for killing them and eating them, we'd probably starve at least temporarily, since it would be difficult to replace animal protein in industrial scale to feed the huge human population in this planet. Even if we were able to replace it with 100% vegetable products, the process of planting/harvesting vegetables also kills animals, such as worms and field mice. So, I think we can't be entirely radical about it and go for some sort of blanket prohibition of any harm done to animals. Nature does have a food chain and animals themselves kill other animals in order to eat.
Most people except the most pathological sociopaths, callous murderers, extremists such as ISIS, or evil dictators, believe that killing a human being is wrong. Most people think that killing most animals (at least for food; some would include hunting or fishing for sport) is not wrong. In between, people will have a spectrum of opinions. Mine happens to draw the line at high intelligence. While I have no problem with killing and eating a chicken, I'd be quite upset at, for example, hunting an orangutan for sport.
Now, am I implying that the less intelligent human beings should be less protected than the more intelligent ones? Not at all. Even retarded human beings have a sense of self and are clearly sentient creatures (except for the very severely retarded, severely brain-damaged, vegetative ones), so, no, I'm not advocating for any kind of eugenics or attribution of higher grade rights for more intelligent humans as compared to mentally retarded ones.
What I'm saying is that humans of all levels of intelligence AND some of the highly intelligent animal species (dolphins, certain species of whales, great apes and other primates, pigs, elephants, and maybe a few others - dogs might be a borderline case, and some studies even quote others like crows, squirrels, and even octopuses as very sentient although I'm not sure I'd go that far), should enjoy rights and protections beyond simply banning cruelty.
So, beating and torturing a dog is a felony in the United States based on cruelty laws, but raising pigs in extremely cruel conditions and butchering them in graphic ways is considered to be perfectly normal, in spite of the fact that pigs are demonstrably much more intelligent than dogs (for example, they can play videogames, understand mirrors, know about what being killed means - and get very distressed while anticipating it, are able to differentiate other pigs individually, etc., way beyond what dogs can do). I think this makes no sense (that is, severely restrict any cruelty against dogs while allowing pigs to be treated in all sorts of despicable manners). I'd go with intelligence first, as a criterion. I'd want all senseless cruelty against animals (any animals) to be be banned and a felony, but I'd only grant personhood and the additional rights that would come with it, to the highly intelligent species, because I think granting personhood to ALL species would be a gross exaggeration. I mean, I don't think that cooking shrimp is a horrible example of animal cruelty and I don't think I'm eating people when I eat shrimp.
Now, do I eat pork? Oh well, I do. I know I'm being contradictory, but I'm just a flawed human being and sometimes I'm not 100% coherent, go figure. But I do have a little pang of guilt when I think about it. I think I *shouldn't* eat pork, but I haven't been able to walk that step, yet. It probably has to do with how used we all are to the idea that pigs are livestock. Cows, however, I consider to be quite stupid, and the same applies to chicken and fish. I have no pangs of guilt when I eat beef, chicken, or fish.
That's my personal opinion and I hope the above is helpful in clarifying it, and I'm ready to respect other people's opinions. I draw the line not as high as those who think only humans should be granted personhood, but not as low as those who want to include all animals.