Heterogeneity of variance components for preweaning growth in Romane sheep due to the number of lambs reared

Table 2 Assumptions of the different models

		Direct genetic			Maternal genetic			Maternal permanent			Litter		Residual
	α ₂	$σ_{d_{1}}^{2}$	$σ_{d_{2}}^{2}$	$ρ_{d_{1} d_{2}}^{}$	$σ_{m_{1}}^{2}$	$σ_{m_{2}}^{2}$	$ρ_{m_{1} m_{2}}^{}$	$σ_{p_{1}}^{2}$	$σ_{p_{2}}^{2}$	$ρ_{p_{1} p_{2}}^{}$	$σ_{l_{1}}^{2}$	$σ_{l_{2}}^{2}$	$σ_{e_{1}}^{2}$	$σ_{e_{2}}^{2}$
Mod(7)	= 1	✓	✓	✓	✓	✓	✓	✓	✓	✓	✓		✓	✓
Mod(6)	= 1	✓	✓	✓	✓		= 1	✓	✓	✓	✓		✓	✓
Mod(5)	= 1	✓		= 1	✓	✓	✓	✓	✓	✓	✓		✓	✓
Mod(4)	= 1	✓		= 1	✓		= 1	✓	✓	✓	✓		✓	✓
Mod(3)	= 1	✓		= 1	✓		= 1	✓		= 1	✓		✓	✓
Mod(2)	= 1	✓		= 1	✓		= 1	✓	✓	✓	✓		✓
Mod(1)	= 1	✓		= 1	✓		= 1	✓		= 1	✓		✓
Mod(Coef)	= 0.7	✓		= 1	✓		= 1	✓		= 1	✓		✓

✓ in two cells indicates that the two components are equal; = × indicates that the component is fixed to x. for litter size i; $σ_{e_{i}}^{2}$ is the residual variance; $σ_{d_{i}}^{2}$ and $ρ_{d_{1} d_{2}}^{}$ are the direct genetic variance and correlation; $σ_{m_{i}}^{2}$ and $ρ_{m_{1} m_{2}}^{}$ are the maternal genetic variance and correlation; $σ_{p_{i}}^{2}$ and $ρ_{p_{1} p_{2}}^{}$ are the maternal permanent variance and correlation; $σ_{l_{i}}^{2}$ is the litter variance

ISSN: 1297-9686