The 1900s-era black and white drawing was then compared to a modern concentrated animal-feeding operation, in which more than 75,000 birds were tightly crammed together. Ellen Silbergeld, a professor of health sciences at Johns Hopkins University, described the dim lighting and noted that the birds live among their feces.

In a Wednesday afternoon lecture, she discussed this and the myriad changes to the industrial production of food animals and how it is affecting public health.

"There is a crisis," she said, noting the rise of antimicrobial-resistant pathogens.

Animals are increasingly given food that contains FDA-approved antibiotics, which in turn increases bacteria's resistance to antibiotics in humans, Silbergeld said.

Source: TheDailyIowan