Table 1.

Parameter estimates obtained using the animal model (AM) and the reaction norm animal model (RNAM)

Parameter	Model
	AM	RNAM
${\sigma }_{a0}^2$	0.014	0.016
${\sigma }_{a1}^2$	–	0.038
${\sigma }_{a0,a1}$	–	− 0.011
${\sigma }_{pe0}^2$	0.028	0.034
${\sigma }_{pe1}^2$	–	0.104
${\sigma }_{pe0,pe1}$	–	− 0.031
${\sigma }_{\mathrm{e}}^2$	0.123	0.120
Genetic correlation	–	− 0.460 ± 0.210

${\sigma }_{a0}^2=$ additive genetic variance for level, ${\sigma }_{a1}^2=$ additive genetic variance for slope, ${\sigma }_{a0,a1}=$ additive genetic covariance between level and slope, ${\sigma }_{pe0}^2=$ permanent environmental variance for level, ${\sigma }_{pe1}^2=$ permanent environmental variance for slope, ${\sigma }_{pe0,pe1}=$ permanent environmental covariance between level and slope, ${\sigma }_{\mathrm{e}}^2=$ residual variance