Citation
Unknown. 1926. “A typical swine herd with with roundworm (Ascaris suum) resulting from indiscriminate breeding and little attention to sanitation. Note improved farrowing shelter in the background. Photograph used as Figure 2 in U.S. Department of Agriculture Technical Bulletin 374, 1933..” Special Collections, USDA National Agricultural Library. Accessed March 28, 2024, https://www.nal.usda.gov/exhibits/speccoll/items/show/8068.