| a longitudinal study of gastrointestinal parasites in canadian dairy farms. the value of an indirect ostertagia ostertagi elisa as a monitoring tool. | the general objective of this study was to evaluate a crude ostertagia ostertagi antigen enzyme-linked immunosorbent assay (elisa) for monitoring gastrointestinal parasites in lactating dairy cattle. a longitudinal study of gastrointestinal parasites in lactating dairy cows was carried out in 38 herds in four provinces of canada (prince edward island, quebec, ontario and saskatchewan) from september 1999 to october 2000. bulk tank milk, cow milk, serum and fecal samples were collected monthly or ... | 2002 | 12127251 |