Ver artículo

In temperate climate regions, gastrointestinal nematodes are still widespread in adult dairy cows, but until now there exists no reliable diagnostic tool that can identify herds where the infection interferes with productivity. The objective of this study was to investigate the relationships between levels of antibodies against Ostertagia ostertagi in bulk tank milk and milk production. Bulk tank milk samples of 2553 dairy herds were obtained in spring and 2104 of these herds were sampled a second time in autumn. The antibody levels against O. ostertagi were determined with a milk ELISA and test results were expressed as an optical density ratio (ODR). The effect of bulk tank milk ODR on three different production parameters, kg milk, % and kg fat, % and kg protein was assessed by a multivariable linear regression model on the herds for which production data were available (n = 1063 and 867 in spring and autumn …