Table 6.

Estimated variance components (±SE) for both direct effect and indirect effects using Model 5 ¹

Parameter	Neck BMS	Body BMS 5	Tail BMS	Total BMS
$${\widehat{\mathit{\sigma }}}_{{\mathit{A}}_{\mathit{D}}}^2$$	0.26 ± 0.11	0.37 ± 0.14	0.34 ± 0.13	2.95 ± 0.90
$${\widehat{\mathit{\sigma }}}_{{\mathit{A}}_{\mathit{D},\mathit{S}}}$$	0.12 ± 0.04	0.27 ± 0.05	0.21 ± 0.04	1.97 ± 0.30
$${\widehat{\mathit{\sigma }}}_{{\mathit{A}}_{\mathit{S}}}^2$$	0.18 ± 0.04	0.27 ± 0.06	0.14 ± 0.04	1.6 ± 0.32
$${}^2{\widehat{\mathit{\sigma }}}_{{\mathit{A}}_{\mathit{T}}}^2$$	1.65 ± 0.25	2.56 ± 0.56	2.19 ± 0.30	19.13 ± 2.40
$${\widehat{\mathit{r}}}_{{\mathit{A}}_{\mathit{DS}}}$$	0.55 ± 0.22	0.67 ± 0.21	0.99 ± 0.23	0.90 ± 0.15
$${}^3{\widehat{\mathit{\rho }}}_{\mathit{s}}$$	0.09 ± 0.05	-0.04 ± 0.04	-0.09 ± 0.03	-0.02 ± 0.04
$${\widehat{\mathit{\sigma }}}_{{\mathit{e}}_{\mathit{m}}}^2$$	1.40 ± 0.12	3.15 ± 0.21	2.80 ± 0.18	14.8 ± 1.01
$${\widehat{\mathit{\sigma }}}_{{\mathit{e}}_{\mathit{f}}}^2$$	3.07 ± 0.20	3.90 ± 0.25	6.10 ± 0.32	24.77 ± 1.54
$${}^4{\widehat{\mathit{\sigma }}}_{\mathit{P}}^2$$	3.54 ± 0.11	4.95 ± 0.14	5.31 ± 0.16	31.09 ± 1.00
$${}^5{\widehat{\mathit{h}}}_{\mathit{D}}^2$$	0.07 ± 0.10	0.07 ± 0.03	0.06 ± 0.02	0.10 ± 0.03
$${}^6{\widehat{\mathit{T}}}^2$$	0.47 ± 0.08	0.52 ± 0.21	0.41 ± 0.06	0.61 ± 0.08

¹Model 5 was y = Xb + Z _D a _D  + Z _S a _S  + Vg * s + e; ²from Equation 2 using a pen size of 3.18; ${}^3{\mathit{\rho }}_{\mathit{s}}=\frac{{\widehat{\mathit{\sigma }}}_{\mathit{g}*\mathit{s}}^2}{{\widehat{\mathit{\sigma }}}_{\mathit{g}*\mathit{s}}^2+0.5\left({\widehat{\mathit{\sigma }}}_{{\mathit{e}}_{{}_{\mathit{m}}}}^2+{\widehat{\mathit{\sigma }}}_{{\mathit{e}}_{\mathit{f}}}^2\right)}$ is the non-genetic correlation between phenotypes of cage mates of the same sex; ⁴ for BMS, phenotypic variance was estimated from a separate analysis using the model y = Xb + e, this was done because our objective was to present a single number for phenotypic variance and heritability, covering both sexes since a single genetic variance was fitted covering both sexes; however, since our aim was to estimate the other model terms with the best fitting model, a separate analysis for phenotypic variance was performed; the standard errors of heritability estimates were calculated from the full model, averaging the residual variances for both sexes; ⁵although Model 4 was slightly better, we presented estimates obtained with Model 5 for reasons of consistency; ${}^5{\widehat{\mathit{h}}}_{\mathit{D}}^2={\mathit{\sigma }}_{{\mathit{A}}_{\mathit{D}}}^2/{\mathit{\sigma }}_{\mathit{P}}^2$. ${}^6{\widehat{\mathit{T}}}^2={\mathit{\sigma }}_{{\mathit{A}}_{\mathit{T}}}^2/{\mathit{\sigma }}_{\mathit{P}}^2$.