aDepartment of Cattle and Sheep Diseases, Swedish University of Agricultural Sciences, 5-750 07, Uppsala, Sweden bUnit of Epidemiology, Swedish University of Agricultural Sciences, 5-750 07, Uppsala, Sweden cAssociation for Livestock Breeding and Production in Dala-Gävleborg, Hamre 618, S-776 00, Hedemora, Sweden dDivision of Epizootiology, National Veterinary Institute S-750 07, Uppsala, Sweden eDepartment of Virology, National Veterinary Institute, 5-750 07, Uppsala, Sweden
Bulk tank milk samples, collected twice with a 1 year interval, from 213 Swedish dairy herds with no vaccination programme against bovine virus diarrhoea virus (BVDV), were tested for antibodies to BVDV using an indirect enzyme-linked immunosorbent assay. The herds were classified into four different BVDV groupings based on changes in the estimated prevalence of BVDV antibody-positive cows in the herds. The estimated mean prevalences of BVDV antibody-positive cows were maintained as > 80% in 58 (27.2%) and as < 10% in 84 (39.4%) of the herds. A recent introduction of the infection was deemed to have occurred in seven (3.3%) of the herds studied. The BVDV groups were compared with regard to parameters related to disease and fertility at herd level. Relationships were assessed using logistic and ordinary linear regression analyses. The risks for clinical mastitis, retained placenta and oestrus-stimulating treatments were higher and the calving intervals were longer in BVDV infected herds, i.e. those herds with an increasing or maintained high prevalence of BVDV antibody-positive cows.
This article was published in Preventive Veterinary Medicine, 23, R. Niskanena, U. Emanuelsonb, J. Sundbergc, B. Larssond and S. Aleniuse, Effects of infection with bovine virus diarrhoea virus on health and reproductive performance in 213 dairy herds in one county in Sweden, 229-237, Copyright Elsevier 1995.