Table 3.

Estimates of variance components and (±) standard errors for litter size and gestation length

Populationa	Modelb	${\mathit{\sigma }}_s^2$	${\mathit{\sigma }}_r^2$	${\mathit{\sigma }}_a^2$	${\mathit{\sigma }}_{a_{LW}}^2$	${\mathit{\sigma }}_{a_{LR}}^2$	${\mathit{\sigma }}_e^2$	h 2
Litter size
LW	GS	0.43 ± 0.13	1.70 ± 0.30	1.81 ± 0.36	–	–	8.26 ± 0.25	0.15 ± 0.03
LR	GS	0.02 ± 0.09	1.22 ± 0.28	1.30 ± 0.31	–	–	8.80 ± 0.27	0.12 ± 0.03
F1	GS	0.10 ± 0.10	1.38 ± 0.28	1.42 ± 0.34	–	–	8.54 ± 0.24	0.12 ± 0.03
F1	BS	0.11 ± 0.10	1.37 ± 0.29	–	0.74 ± 0.23	0.56 ± 0.245	8.52 ± 0.24	0.12 ± 0.03
Gestation length
LW	GS	0.21 ± 0.03	0.33 ± 0.05	0.68 ± 0.09	–	–	0.78 ± 0.02	0.34 ± 0.04
LR	GS	0.23 ± 0.03	0.26 ± 0.05	0.64 ± 0.09	–	–	0.82 ± 0.03	0.33 ± 0.04
F1	GS	0.16 ± 0.02	0.23 ± 0.06	0.81 ± 0.11	–	–	0.90 ± 0.03	0.39 ± 0.04
F1	BS	0.16 ± 0.02	0.17 ± 0.06	–	0.42 ± 0.08	0.40 ± 0.08	0.90 ± 0.03	0.40 ± 0.04

Variance components: service sire (${\mathit{\sigma }}_s^2$), permanent environment (${\mathit{\sigma }}_r^2$), additive (${\mathit{\sigma }}_a^2$), additive for the alleles of the F1 population inherited from the LW (${\mathit{\sigma }}_{a_{LW}}^2$) and LR (${\mathit{\sigma }}_{a_{LR}}^2$) populations, and error (${\mathit{\sigma }}_e^2$). h ²: heritability

^aLarge White (LW), Landrace (LR), two-way crossbred (F1)

^bTraditional genomic selection model (GS) and a model that accounts for breed-specific effects (BS)