Table 1.

Observed number of animals in each herd, which tested negative or nonnegative for Leptospira interrogans serovar Hardjo using Ceditest serum ELISA test, and the bulk milk PP from each herd using Ceditest milk ELISA test. Serum PP cutoff criteria were as per test manufacturer guidelines: 0 ≤ negative < 20, 20 ≤ inconclusive ≤ 45, and positive > 45. Due to the very small number of animals testing inconclusive (3% of total), this category was combined with the positive category

Farm	Bulk milk PP	No. negative cows	No. inconclusive/positive cows
1	14.28	200	2
2	17.78	51	0
3	20.35	125	1
4	34.12	47	1
5	45.50	52	1
6	73.99	64	5
7	80.68	107	9
8	109.60	19	27
9	115.08	21	56
10	121.36	35	32
11	122.83	28	55
12	144.27	5	36
	Total	754	225