Figure 1

Proportion of Giardia duodenalis positive fecal samples from central and western United States, classified by pen order and concentration of cysts. Entry pens are where cattle first enter the feedlot from pasture, middle pens are where feedlot diets transition from high roughage to high concentrates, and exit pens are where cattle are fed high concentrate rations immediately prior to harvest. Negative fecal samples are not shown.