title: A longitudinal survey of anti-Ostertagia ostertagi antibody levels in individual and bulk tank milk in two dairy herds in Normandy.
abstract: The Ostertagia-specific antibody levels in milk were monitored in 2 dairy herds to investigate seasonal variations and the relationship between individual and bulk tank milk antibody levels. Bulk tank and individual milk samples from all lactating animals were collected over a 1-year period at weekly and monthly intervals, respectively. The Ostertagia-specific antibody levels were measured with an indirect ELISA and the test results were expressed as optical density ratios (ODR). A clear seasonal pattern that followed the expected intake of infectious larvae was observed in the individual and bulk tank milk antibody levels of both herds. Within each herd, there was a large variation in the individual ODRs. This variation remained large when the distribution of individual ODRs was plotted according to high and low bulk tank milk ODR categories. The results suggest that the effect of seasonal variations on cut-off levels that predict production responses after anthelmintic control, needs to be assessed.
authors.affiliation: Department of Virology, Parasitology and Immunology, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium. johannes.charlier@ugent.be
authors.forename: Johannes
authors.initials: J
authors.lastname: Charlier
authors.forename: Philippe
authors.initials: P
authors.lastname: Camuset
authors.forename: Edwin
authors.initials: E
authors.lastname: Claerebout
authors.forename: Bruno
authors.initials: B
authors.lastname: Courtay
authors.forename: Jozef
authors.initials: J
authors.lastname: Vercruysse
mesh_terms: D000818:Animals; D000909:Antibodies, Helminth / Q000276:immunology / Q000302:isolation & purification*; D002417:Cattle; D002418:Cattle Diseases / Q000175:diagnosis* / Q000453:epidemiology / Q000276:immunology*; D003612:Dairying; D005260:Female; D005602:France / Q000453:epidemiology; D007774:Lactation; D008137:Longitudinal Studies; D008892:Milk / Q000276:immunology*; D010028:Ostertagia / Q000276:immunology*; D010029:Ostertagiasis / Q000097:blood / Q000175:diagnosis / Q000276:immunology / Q000662:veterinary*; D012621:Seasons; D013997:Time Factors
chemical_list: D000909:Antibodies, Helminth