Table 1.

Descriptive statistics and the estimated heritability (h²) and repeatability (r) of the three semen quality traits

Trait (unit)	N a	Mean (SD)	Min	Max	h2 ± SE b	r ± SE b
Ejaculate volume	332,531	6.76 (2.97)	1	25	0.13 ± 0.02	0.28 ± 0.01
Sperm concentration	330,270	12.67 (4.61)	1	30	0.11 ± 0.02	0.32 ± 0.01
Sperm motility	330,199	0.67 (0.16)	0.1	0.98	0.08 ± 0.02	0.28 ± 0.01

^a Number of records

^b $h^2=\frac{{\mathrm{\sigma }}_{\mathrm{a}}^2}{{\mathrm{\sigma }}_{\mathrm{a}}^2+{\mathrm{\sigma }}_{\mathrm{pe}}^2+{\mathrm{\sigma }}_{\mathrm{e}}^2}$, and $r=\frac{{\mathrm{\sigma }}_{\mathrm{a}}^2+{\mathrm{\sigma }}_{\mathrm{pe}}^2}{{\mathrm{\sigma }}_{\mathrm{a}}^2+{\mathrm{\sigma }}_{\mathrm{pe}}^2+{\mathrm{\sigma }}_{\mathrm{e}}^2}$; where ${\mathrm{\sigma }}_{\mathrm{a}}^2$ is additive genetic variance, ${\mathrm{\sigma }}_{\mathrm{pe}}^2$ is permanent environment variance, and ${\mathrm{\sigma }}_{\mathrm{e}}^2$ is residual variance