The expression "felt [or feel or be treated] like a piece of meat" is fairly common today in the approximate sense of "felt dehumanized and objectified, particularly as an object of sexual interest" (my definition).
I was somewhat surprised to discover that the expression is not terribly old. I had expected to find that it had emerged in print from tough-guy noir fiction of the 1930s and 1940s. But the earliest relevant matches for "like a piece of meat" that an Elephind search returns are from the 1970s. From Lynne Margolis, "Dorm Life Evolves into Zoo Story," in the [University Park, Pennsylvania] Daily Collegian (September 16, 1976):
Let's face it, the average dorm resident is not 21, and therefore cannot get into bars to find any action. One has the alternative of walking ll the way to a frat house and hoping to get in (for less than the promise of his first-born son). Then, depending on sex, one is treated like a nobody in a room full of strangers, or like a piece of meat.
From Stacy Smith, "TV Q and A," in the San Bernardino [California] Sun (May 29, 1978):
Q. Anson William once commented on a TV talk show he hates going to Hollywood parties. Why? — F.B., Pensacola, Fla.
A: "It's mostly the parties set up by studios and public relations people that I hate going to," Anson clarifies. "I feel like a piece of meat in those situations. I feel cheapened and I feel mad because I'm thought of as a commodity. Maybe it's the truth, but I don't want to be reminded of it."
And from Kurt Cobb, "Harris Condemns Power Draft Gives Gov't," in the Stanford [California] Daily (March 9, 1979):
He [David Harris] also said that plans which call for the option of service outside of the military cannot be classified as "service" at all. "Service is an act done by willing people of their own free will. ... Coercion has nothing to do with service," he said. "You're going to be a piece of meat to them and they're going to treat you like a piece of meat."
An interesting (but not entirely on-point) example of the simile applied to a person's experience appears in "Eichmann Examination No Over," in the Canberra [Australia] Times (July 21, 1961):
JERUSALEM, Thursday (A.A.P.).—The Israeli Attorney General, Mr. Hausner, ended his cross-examination of Adolf Eichmann after a 10-day battle of question and answer.
The cross-examination lasted 50 hours.
It provoked angry outbursts both from Eichmann, who said at one stage he was being grilled like a piece of meat, and from the prosecutor himself.
Eichmann's assertion. of course, was expressed in German and presumably involves no awareness of the sense of "like a piece of meat"—or of the double meaning of "grilling"—in idiomatic English.
Another widely reported instance of the expression appeared in remarks by Rodney King, in "Rodney King Gets Award of $3.8 Million," in the Los Angeles [California] Times (April 20, 1994):
During the trial, King had graphically described the pain and humiliation he felt on the night he was beaten by Los Angeles police officers in the San Fernando Valley, telling jurors: "I felt like I had been raped. ... I felt like a cow that was waiting to be slaughtered, just like a piece of meat.
Here the first image is of sexual violence and then of an animal being readied for slaughter.
The central emotion expressed in these examples is not shame but anger, repulsion, or revulsion—and recognizing the key elements of the reaction, I think, is crucial to correctly understanding the sense of the expression itself. A person who feels treated like a piece of meat may feel a degree of shame at having been subjected to dehumanizing treatment—paradoxical though that feeling may be—but the person is likely to have an even stronger emotional reaction of anger and disgust at the aggressors' predatory and disrespectful behavior, along with a lucid sense that the treatment to which the person was subjected was unjust. This at any rate is the complex of feelings that I think many people in the United States would associate with the expression "I feel like a piece of meat."