Investigation of Anaplasma marginale Seroprevalence in a Traditionally Managed Large California Beef Herd

Table 2

Apparent seroprevalence and 95% CI for Anaplasma marginale at baseline and final sampling times and values for McNemar’s test comparing seroprevalence within groups at baseline and final sampling times for three cattle cohorts from a beef herd in California which were followed up for A. marginale seroconversion.

Age group	Baseline sample		Final sample
	AP (%)	95% CI	AP (%)	95% CI
Group 1 heifers	22.50	(9.56, 35.44)	67.50	(52.98, 82.02)
Group 2 heifers	42.42	(30.50, 54.35)	89.06	(81.42, 96.71)
Cows^‡	86.49	(75.47, 97.50)	91.89	(83.10, 100.00)

Within a column, values with different superscript letters are significantly different ().
McNemar’s test value < 0.001.
^†Two group 2 heifers were lost to follow-up between the initial and final sample days.
^‡McNemar’s test value .