Fasciola hepatica and Ostertagia ostertagi in Norwegian cattle : diagnostic tests and farmers’ management

• Main Author: Opsal, Tonje
• Format: Dissertation
• Language: English
• Subjects: Diagnostic tests; Fasciola hepatica; Ostertagia ostertagi; Pasture management; Pasture parasites

Infections caused by pasture parasites (PP) impact animal health and welfare, and cause some of the most important production-limiting diseases in grazing cattle worldwide. This thesis will focus on the brown stomach worm Ostertagia ostertagi and the common liver fluke Fasciola hepatica, as they are considered among the PP of highest importance in Norway. Climate changes and the emergence of anthelmintic resistance (AR) can intensify the future challenges posed by PP. This has led to a global call for coordinated efforts to improve parasite control. However, no research on PP in Norwegian cattle has been conducted since the 1980s. Knowledge of the farmers’ current management and perception of PP, in addition to improved opportunities for diagnostics, can contribute to a more efficient and sustainable control of PP. The main aim of this thesis was to investigate the perceptions and management strategies of PP at the farm level among Norwegian cattle farmers, and to evaluate the performance of different diagnostic tests for F. hepatica and O. ostertagi in Norwegian cattle units. These aims were assessed using a questionnaire survey, a cross-sectional field study and a diagnostic test evaluation.