Table 2.

Matrix correlations between PRRSV genetic similarity and similarity of PRRS clinical disease signs (52 farms, IL, USA; 1997–1998)

Clinical disease sign	Mantel test parameters
	na	rb	Pc
Abortion	42	0.18	0.24
Infertility in sows	42	0.01	0.13
Death in sows	42	0.69	0.02
Preweaning mortality	42	−0.05	0.37
Respiratory disease in:
Nursery pigs	48	0.17	0.19
Grow/finish pigs	54	−0.05	0.37
Longer time to market for grow/finish pigs	54	−0.07	0.28

^aValues indicate sizes of matrices, and vary due to missing data.

^bValues represent the standardized form of the Mantel test statistic proposed by Smouse et al. (1986).

^cProbabilities are one-tailed when relationships were in the predicted (positive) direction, and two-tailed otherwise.