From a Marxist standpoint, it is impossible to discount the consumer capitalist enterprise in which animals are commoditized (trapped, mutilated, and killed). Animals, once they become part of the assembly line, cease to be chickens, cows, or pigs, but just another commodity. Categorizing them as "food products" allows them to be exploited as a "resource."
For Ms. Davis, this inquiry culminated in her brilliant work, "The Holocaust and the Henmaid's Tale: A Case for Comparing Atrocities." Here, she draws parallels between the Holocaust and the institutionalized abuse on factory farms. It's similar to the Isaac Bashevis Singer story, "The Letter Writer," where he offers anecdotes about the Chicago stockyards: "In relation to [animals], all people are Nazis; for the animals, it is an eternal Treblinka."
Theory, critique, and analysis are important, but Ms. Davis and UPC hardly exist in a vacuum. Since 1999, UPC has hosted 12 annual conferences on farmed animal advocacy issues. UPC's Forum on Direct Action for Animals, June 26 to 27, 1999, introduced US activists "to the strategy developed by Australian activist Patty Mark, of Open Rescues, in which undercover investigators admit to rescuing animals and documenting the conditions of their abuse." In 2012, 2013, and 2014, UPC hosted conferences in Berkeley, California, on the topic of "Conscious Eating: What is Truly Sustainable?"