Association between herd exposure to BVDV-infection and bulk milk somatic cell count of Flemish dairy farms

Jozef Laureynsa,∗, Sofie Piepersa, Stefaan Ribbensb, Steven Sarrazina, Sarne De Vlieghera, Jean-Marie Van Crombruggec, Jeroen Dewulfa

  • a Department of Reproduction, Obstetrics, and Herd Health, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, B-9820 Merelbeke, Belgium
    b Flemish Animal Health Service (DGZ), Deinse Horsweg 1, B-9031 Drongen, Belgium
    c Flanders Milk Control Centre (MCC), Hagenbroeksesteenweg 167, B-2500 Lier, Belgium

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The purpose of this study was to investigate the statistical association between herd bovine viral diarrhoea (BVD) status based on bulk milk antibody detection and monthly
bulk milk somatic cell count (BMSCC) as a reflection of the udder health. A distinction was made between vaccinating and non-vaccinating herds via a questionnaire concerning
BVD-vaccination. No significant difference in BMSCC was found between vaccinating (228,300 cells/ml; SD 180,019) and non-vaccinating (237,070 cells/ml; SD 77,900) herds.
Non-vaccinating herds (n = 243) were selected, and the relationship between a single BVDVantibody titre and the BMSCC of each herd over a 12-month observation period evaluated.

For this purpose, the non-vaccinating herds were divided into five groups depending on bulk milk BVDV-antibody titres. Overall, no significant relationship between the antibody
titre and the BMSCC was found. Still, when comparing the category with the lowest S/P ratio (essentially BVDV-naïve herds; BMSCC = 211,390 cells/ml) with the combined four
other categories (BMSCC = 242,790 cells/ml), a significant difference in BMSSC was observed (P = 0.01).