Bovine viral diarrhoea virus seroprevalence and vaccination usage in dairy and beef herds in the Republic of Ireland

Table 4 Bovine viral diarrhoea (BVD) herd status for 111 herds in Ireland during 2009 (based on a comparison of bulk milk and pooled serum BVDV antibody results) in non-vaccinated herds

BVD herd status based on bulk milk analysis (PP ≥ 2.5)	BVD herd status
	(PP 2.12)		(PP 7.58)
	Negative	Positive	Negative	Positive
Negative	1	4	2	3
Positive	0	60	0	60
% agreement in classification	93.8%		95.4%
(κ-value)	(0.32)		(0.55)

The pooled serum results are separately presented at two different cut-off percentage positivity (PP) values (2.12 and 7.58). The level of agreement in BVD herd status, for non-vaccinated herds at each of the two cut-offs is presented, using kappa statistics.

ISSN: 2046-0481