Table 1. Sperm motility traits and principle components generated from the sets of differences in values between dyed und undyed sperm samples for each trait.

Trait (difference between scores of undyed and dyed samples)	PC1	PC2
VAP: average path velocity	0.94	0.28
VCL: curvilinear velocity	0.57	0.80
VSL: straight-line velocity	0.98	0.04
STR: straightness	0.50	−0.73
LIN: linearity	0.85	−0.52
ALH: amplitude of lateral head displacement	0.12	0.87
BCF: beat cross frequency*	−0.89	0.07
Eigenvalue	3.93	2.29
Cumulative per cent of variance explained	56.15	88.87

Shown are trait loadings, eigenvalues and cumulative per cent of variance in composite trait variables of the first two principle components.

^*BCF was square root transformed prior to analyses.