Table 1.

Comparison of Neospora caninum ELISA results from serum (cow level, 1 sampling date) and bulk milk (herd level, 4 sampling dates) from 11 dairy farms

	Bulk Milk ELISA S/P Ratioa				Cow Level Serum ELISA Test Resultsb
Herd	May ’04	May ’05	June ’05	Sept ’05	Prevalence (%)	Number of positive cows	Total number of cows
1	0.04	0.25	0.64	0.15	1.3	1	77
2	0.34	0.82	0.62	0.25	5.7	2	35
3	0.85	0.28	0.31	0.40	1.5	1	66
4	0.61	0.28	0.33	0.41	5.6	4	72
5	0.50	0.47	0.64	0.41	9.8	4	41
6	0.65	0.21	0.14	0.50	15.4	4	26
7	0.43	0.70	0.65	0.67	17.5	7	40
8	0.67	0.54	0.34	0.78	17.9	7	39
9	0.42	0.64	0.64	0.99	27.4	23	84
10	0.55	0.69	0.60	1.00	30.6	22	72
11	0.14	1.01	0.75	1.09	17.9	12	67

^aSample-to-Positive Ratio — Bold printed numbers indicate a positive bulk milk result (S/P ≥ 0.60)

^bIndividual serum samples were collected on the same day as the bulk milk sample in September 2005. All numbers refer only to lactating cows contributing to the bulk tank on the sampling date