Molecular detection of Cooperia oncophora and Ostertagia ostertagi in cattle: Comparison of sample processing and detection on ddPCR and qPCR platforms.

Faecal samples were obtained from 77 first season grazers from 20 Norwegian dairy herds in autumn 2020 for analysis of Cooperia oncophora and Ostertagia ostertagi infection. Strongylid eggs per gram of faeces (EPG) were determined for each sample and the samples underwent larval culture. DNA was extracted from the faeces at different stages of the culture preparation: from faecal slurry (FS), direct extraction before culture (DBC), and direct extraction after culture (DAC).

Estimation of diagnostic sensitivity and specificity of abattoir registrations and bulk tank milk ELISA as herd-level tests for Fasciola hepatica using Bayesian latent class modelling.

The common liver fluke, Fasciola hepatica, is a trematode parasite found worldwide, typically with a focal distribution due to its requirement for suitable climatic and environmental conditions to complete its lifecycle. Bovine fasciolosis causes suboptimal production and economic losses, including liver condemnation at slaughter. The lack of reliable diagnostic methods is a disadvantage to the increasing demand for surveillance and control.

Comparison of diagnostic methods for assessment of Ostertagia ostertagi exposure in Norwegian dairy herds.

Background: The gastrointestinal nematode (GIN) Ostertagia ostertagi can cause severe disease in first season grazers (FSG) and impaired performance due to subclinical infections in adult cows. Diagnostic methods to assess exposure include faecal egg count and detection of specific antibodies using antibody-ELISAs resulting in an optical density ratio (ODR). Using the ELISA test on bulk tank milk (BTM) allows for a herd level diagnosis.

Gastrointestinal nematodes and Fasciola hepatica in Norwegian cattle herds: a questionnaire to investigate farmers' perceptions and control strategies.

Background: Pasture management influences the prevalence and impact of the pasture parasites (PP) in cattle herds, which cause production-limiting disease worldwide. Evaluating farmer management strategies is vital when considering sustainable PP control practices. The aim of this questionnaire-based study was to describe the pasture management and control strategies regarding PP in Norwegian beef cattle (BC) and dairy cattle (DC) production systems with a focus on gastrointestinal nematodes (GIN) and Fasciola hepatica.