Table 2.

Variance components^a using a multi-trait model and a single-trait model

Parameterb	IFL	CR	AIS	NRR56	ICF	DO
${\sigma }_{a_0}^2$	56.6	1.851 E-03	0.018	1.352 E-03
${\sigma }_{a_1}^2$	325.8	2.921 E-03	0.101	1.120 E-03	120.5	539.7
${\sigma }_{a_2}^2$	282.3	1.937 E-03	0.100	1.292 E-03	69.1	380.0
${\sigma }_{a_3}^2$	238.0	2.821 E-03	0.101	2.697 E-03	59.5	396.6
${\sigma }_{e_0}^2$	4326.4	0.178	1.392	0.162
${\sigma }_{e_1}^2$	9398.3	0.204	3.390	0.210	1059.5	10,520.4
${\sigma }_{e_2}^2$	9073.3	0.187	3.642	0.217	818.8	9862.0
${\sigma }_{e_3}^2$	8944.9	0.189	3.642	0.221	798.6	9660.6
${\widehat{h}}_0^2$	0.013(0.003)	0.010(0.002)	0.013(0.002)	0.008(0.002)
${\widehat{h}}_1^2$	0.034(0.005)	0.014(0.003)	0.029(0.005)	0.005(0.002)	0.102(0.008)	0.049(0.006)
${\widehat{h}}_2^2$	0.030(0.005)	0.010(0.003)	0.027(0.005)	0.006(0.003)	0.078(0.009)	0.037(0.006)
${\widehat{h}}_3^2$	0.026(0.006)	0.015(0.005)	0.027(0.006)	0.012(0.005)	0.069(0.011)	0.039(0.007)
${\sigma }_{a_{123}}^2$	257.8	2.314 E-03	0.095	1.215 E-03	86.5	433.8
${\sigma }_{{\mathit{pe}}_{123}}^2$	804.5	5.285 E-03	0.317	5.664 E-03	41.3	1173.8
${\sigma }_{e_{123}}^2$	8438.8	0.191	3.214	0.210	911.3	9034.1
${\widehat{h}}^2$ 123	0.027(0.004)	0.012(0.002)	0.026(0.003)	0.006(0.001)	0.083(0.006)	0.041(0.005)

^a ${\sigma }_{a_i}^2\left(i=0,1,2,3\right)$ = additive genetic variance of ith parity using multi-trait models (model 1); ${\sigma }_{e_i}^2\left(i=0,1,2,3\right)$ = residual variance of ith parity using multi-trait models (model 1); ${\widehat{h}}_i^2$ = estimated heritability of ith parity using multi-trait models (model 1); ${\sigma }_{a_{123}}^2$ = additive genetic variance of a cow trait over parities using single-trait models (model 4); ${\sigma }_{\mathit{pe}123}^2$ = permanent environmental variance of a cow trait over parities using single-trait models; ${\sigma }_{e_{123}}^2$ = residual variance of a cow trait over parities using single-trait models (model 4); ${\widehat{h}}_{123}^2$ = estimated heritability of acow trait over parities using single-trait models

^b IFL interval from first to last insemination, CR conception rate at first insemination, AIS number of inseminations per conception, NRR56 non-return rate at 56 days after first insemination, ICF interval from calving to first insemination, DO days open