Table 4. Variance components and heritability estimates from five models for backfat thickness and carcass weight traits

Model		Variance components		Heritabilities
		Backfat thickness (mm)	Carcass weight (kg)	Backfat thickness (mm)	Carcass weight (kg)
1 (NULL)	Vg	13.5 ± 1.3	31.4 ± 3.6	0.44 ± 0.03	0.31 ± 0.03
	Ve	17.1 ± 0.8	69.2 ± 2.7
2 (PC_F)	Vg	12.1 ± 1.3	24.9 ± 3.7	0.41 ± 0.03	0.26 ± 0.03
	Ve	17.5 ± 0.8	71.3 ± 2.8
3 (GBC_F)	Vg	13.7 ± 1.3	26.0 ± 3.4	0.44 ± 0.03	0.27 ± 0.03
	Ve	17.1 ± 0.8	70.6 ± 2.7
4 (PC_R)	Vg	13.2 ± 1.3	28.1 ± 3.6	0.41 ± 0.04	0.23 ± 0.04
	Vpc	1.6 ± 1.7	23.7 ± 15.1	0.05 ± 0.05	0.19 ± 0.1
	Ve	17.2 ± 0.8	69.9 ± 2.7
5 (GBC_R)	Vg	13.5 ± 1.3	27.1 ± 3.5	0.44 ± 0.03	0.23 ± 0.04
	Vgbc	0.2 ± 0.3	22.3 ± 14.3	0	0.19 ± 0.1
	Ve	17.1 ± 0.8	70.2 ± 2.8

Variance components are the genetic additive variance (V_g) and the error variance (V_e). In addition, the Model 4 (PC_R) and the Model 5 (GBC_R) estimates additional genetic variance components (V_pc and V_gbc).
PC, principal components; GBC, genomic breed composition.