The objective of this study was to evaluate the ability of 2 bulk tank milk tests to correctly classify dairy goat and dairy sheep farms as containing lactating animals infected with Mycobacterium avium ssp. paratuberculosis. Twenty-nine dairy goat herds and 21 dairy sheep flocks in Ontario, Canada were visited in 2011 to collect blood and fecal samples from 20 randomly selected animals and a bulk tank milk sample. The fecal samples underwent fecal culture (Bactec MGIT) and fecal PCR testing (Tetracore), the serum was tested using the Parachek ELISA and the bulk tank milk was tested using PCR (IS900 PCR) and the IDEXX ELISA utilizing the enhanced hyper-ELISA protocol (conjugate incubation time and color development phase were doubled). Sensitivity (Se) and specificity (Sp) for both tests were estimated using the individual animal tests, interpreted at the herd-level, as the reference test. A herd or flock was classified as positive if one or more of the 20 animals tested positive on the specific test (Table 1). No goat herds tested positive on the bulk tank milk PCR test (Se 0%; Sp 100%) while 8/29 (27.6%) herds tested positive on the hyper-ELISA. Of the dairy sheep flocks tested, 3/19 (15.8%) were positive using the PCR-based testing (Se 25%; Sp 100%) while 8/21 (38.1%) were positive using the hyper-ELISA test. The hyper-ELISA yielded higher Se in dairy sheep than in dairy goats (Table 1). In summary, the hyper-ELISA test demonstrated higher Se and Sp than the PCR test. However, further analysis, using a larger sample size, is needed to determine if randomly sampling 20 animals may give more accurate herd-level status. Table 1. Sensitivity and specificity estimates of a bulk tank milk hyper-ELISA test for paratuberculosis in 29 dairy goat herds and 21 sheep flocks in Ontario, Canada

	Reference Test	Sensitivity (95% CI)	Specificity (95% CI)
Dairy Goats	Fecal culture	34.8%	100%
		(16.4–57.3)	(64.9–100)
	Fecal PCR	33.3%	100%
		(15.3–56.8)	(63.2–100)
	Serum ELISA	43.8%	92.3%
		(24.2–67.1)	(65.2–99.1)
Dairy Sheep	Fecal culture	50.0%	77.8%
		(21.1–78.9)	(40.0–97.2)
	Fecal PCR	46.7%	83.3%
		(21.3–73.4)	(35.9–99.6)
	Serum ELISA	87.5%	92.3%
		(47.4–99.7)	(64.0–99.8)