title: Anti-Neospora caninum antibodies in milk in relation to production losses in dairy cattle.
abstract: A comprehensive field study was carried out with the following objectives: (a) to assess the usefulness of individual and bulk tank milk analysis for determining Neospora caninum serostatus in individual cows and herds, and (b) to study the associations between N. caninum infection status (based on milk testing), and several productive and reproductive parameters in the animals. Antibodies were detected with a commercially available ELISA test (Bio K 192/5). Analysis of paired serum and milk samples from 1134 lactating cows on 38 farms revealed that 97.6% of the ELISA results were coincident, irrespective of whether serum or milk samples were used. Moreover, multiple linear regression analysis revealed that 86.0% of the variations in ELISA values in milk were due to variations in the serum. The measurement of antibodies in bulk tank milk was a good estimator of the herd level status of N. caninum infection, and enabled detection of infection in 94.7% herds with ≥10.0% seropositive cows and/or in all herds with >4% highly seropositive cows. The odds ratio for abortion in seropositive animals was 9.1 times higher than in seronegative animals. The infection serostatus was also a significant risk factor, as the odds ratio for abortion was even higher (12.0 times) in cows categorized as highly seropositive. ELISA values for the bulk milk from 387 randomly selected herds were negatively associated with average milk production. Moreover, milk production losses mainly occurred on farms categorized as highly positive (i.e. herds with ≥20.0% seropositive cows).
authors.affiliation: Laboratorio de Parasitología, Centro de Investigaciones Agrarias de Mabegondo, Instituto Galego de Calidade Alimentaria-Xunta de Galicia, Carretera AC-542 de Betanzos a Mesón do Vento, Km 7,5, CP 15318, Abegondo (A Coruña), Spain. marta.gonzalez.warleta@xunta.es
authors.forename: Marta
authors.initials: M
authors.lastname: González-Warleta
authors.forename: José Antonio
authors.initials: JA
authors.lastname: Castro-Hermida
authors.forename: Carmen
authors.initials: C
authors.lastname: Carro-Corral
authors.forename: Mercedes
authors.initials: M
authors.lastname: Mezo
mesh_terms: D000034:Abortion, Veterinary / Q000453:epidemiology / Q000469:parasitology; D000818:Animals; D000913:Antibodies, Protozoan / Q000032:analysis*; D002417:Cattle; D002418:Cattle Diseases / Q000097:blood / Q000175:diagnosis / Q000453:epidemiology* / Q000469:parasitology*; D003048:Coccidiosis / Q000175:diagnosis / Q000662:veterinary*; D004797:Enzyme-Linked Immunosorbent Assay / Q000662:veterinary; D016014:Linear Models; D008892:Milk / Q000469:parasitology*; D018688:Neospora / Q000276:immunology / Q000302:isolation & purification*; D012307:Risk Factors; D013030:Spain / Q000453:epidemiology
chemical_list: D000913:Antibodies, Protozoan