| ostertagia ostertagi antibodies in milk samples: relationships with herd management and milk production parameters in two mediterranean production systems of spain. | the present study analyzed ostertagia ostertagi antibodies by indirect elisa in milk samples in two cattle systems in mediterranean spain to indirectly monitor gastrointestinal nematode (gi) parasitism effects on production. individual samples from 10 animals and the corresponding milk herd samples were collected from 133 herds in girona (intensive management) and 123 herds in minorca (extensive management). both locations showed high and significant positive relationships between average optica ... | 2009 | 19464718 |