Table 4.

Genetic parameters of temperament estimates¹

Effect2	PS3		EV		TS
	All	Subset	All	Subset	All	Subset
${\text{σ}}_a^2$	0.240	0.313	0.305	0.266	0.238	0.263
${\text{σ}}_c^2$	0.321	0.288	0.301	0.352	0.260	0.272
${\text{σ}}_p^2$	0.945	0.958	1.01	1.017	0.710	0.748
$h^2$	0.26 ± 0.03	0.33 ± 0.05	0.30 ± 0.03	0.26 ± 0.04	0.34 ± 0.03	0.35 ± 0.05
$c^2$	0.35 ± 0.03	0.30 ± 0.04	0.30 ± 0.03	0.35 ± 0.03	0.37 ± 0.03	0.36 ± 0.05

¹All: parameters were estimated from repeated records analyses using all data. Subset: For comparison to random regression results, parameters were estimated from repeated record analyses that included only the data for each trait used in the quadratic random regression analyses (animals with less than three records were not included).

² ${\text{σ}}_a^2$, ${\text{σ}}_c^2$, ${\text{σ}}_p^2$, $h^2$ and $c^2$ represent estimates of additive genetic variance, permanent environmental variance, phenotypic variance, narrow sense heritability, and permanent environmental effects as a proportion of the phenotypic variance, respectively.

³PS = pen score, a subjective measure of temperament, in which reactions of an individual calf to a constant experienced evaluator within a pen of three to five calves are scored on a scale of 1 to 5 (1 = calm, 5 = excitable). EV = exit velocity, an objective measure of temperament, defined as the rate (m/s) in which a calf travels 1.83 m upon immediately exiting a squeeze chute. TS = temperament score, numerical average of pen score and exit velocity.