| prevalence of cryptosporidium muris-like oocysts among cattle populations of the united states: preliminary report. | as part of a national survey for bovine, cryptosporidium muris oocysts, fecal smears in the form of up to 144, 3- to 5-mm dots per glass slide were prepared from pen samples at dairies and feedlots in the eastern and western united states. acid-fast staining was followed by light microscopic evaluation at x100. samples from 150 dairies numbered 48,810 and those from 30 feedlots, 47,064. positive samples were found at 102 (68%) dairies and 24 (80%) feedlots. overall, prevalence of positive sample ... | 1991 | 1818141 |