I've never heard she is an animal rights supporter. From what I know of her work, she supports studying animal behavior so animal agriculture can work with the animals in a more efficient manner.
Less stress on the animals means more, and better quality milk and meat.
Meat quality suffers dramatically when hogs and cattle are stressed right before slaughter in slaughter facilities. There is equipment and pen designs that can lessen that stress, and put higher quality meat in the meat case.
Pork for instance, will get an unnatural red color, or be soft and mushy (as opposed to its normal pink color) if the animals are overly stressed.
And also how the animals are loaded and trucked to slaughter is very important.
I'm all for that.
If Ms Grandin has gone beyond that, that's new to me.
PETA was attempting to shove her on Agri for a six-figure salary as a “consultant” which is more than any rabbi, mashgiach, shochet, or treiber makes.
If Agri wanted to hire her on their own, that’s their business, but not as a result of threats, shakedowns and a smear campaign from PETA.