Okay, I re-read (re-skimmed I must admit) Grandin's article, and besides speciesism, which she says she will not address, here's her only justification for why animals can be viewed as property ...
How can I justify eating meat when I say that animals deserve the same protections whether or not they are property or non-property? The cattle I have eaten would have never lived at all if we had not raised them. Another viewpoint from a reviewer is that this does not justify eating them because that perpetuates more cattle and more care. It is my opinion that having more cattle is justified provided we take care of their welfare.
I simply do not understand how one can think they are taking care of an animals welfare when they are killing them, often at a very young age. A cow can live 20+ years, but cows killed for beef might not make it to the age 2. That's only "looking out for its welfare" before you drastically shorten its life for your own desire.
She seems to think that humans were responsible for the very existence of the animal, that humans had the liberty to end the cows life at their whim. This next point is a bit off-topic, but I believe related. If we can kill and eat cows and consider them property because their very existence depended on humans, what does this mean for animals whose existence is natural?
How can a human regard a deer as property or a fish as property when they are not a direct result of animal husbandry? I believe the real answer is the one Grandin refuses to address: speciesism ...
spe·cies·ism
discrimination in favor of one species, usually the human species, over another, especially in the exploitation or mistreatment of animals by humans.
We do it because we can. And because it's been done, we regard it as right. Vegans and vegetarians are simply suggesting that a history of behavior is not in itself an indication of the morality of that behavior, especially once viable alternatives are available.
But we (vegans and vegetarians) are relatively early adopters of this practice, and society has only recently developed to a point that veganism is a viable alternative. Those currently eating meat should not consider themselves in any way inferior, nor should vegans or vegetarians consider themselves superior to those who continue to eat meat. Like many other areas in our lives, we come to realize better ways to live and live with others. Each person should (in most cases) be allowed to come to these realizations in their own time. Eat meat, until you stop wanting meat. If you never stop wanting meat, then eat it.
I tried to argue much earlier against the OP by pointing out that people are far more complex than they were trying to portray them, i.e. "vegans are better people". Some meat eaters may have personal characteristics that easily tip the balance and make them "better people" over those who simply don't eat meat. That viewpoint, someone called "sophistry".
Regardless of any specific habit we have, our goal should be to become better, kinder, more compassionate people to all the beings in the world. That is a difficult enough task as it is. How any person chooses to undertake that transformation (or whether they choose it at all) is up to them and will be unique to every individual. Just being on that path is sufficient. But we sure do like to argue about how we well we walk it.