Estimation of genetic variance for macro- and micro-environmental sensitivity using double hierarchical generalized linear models

Table 8 Estimated genetic parameters for macro- and micro-environmental sensitivity of milk yield in dairy cattle

Parameter	Macro–micro		Macro		Micro		Simple
Parameter	Estimate	SE	Estimate	SE	Estimate	SE	Estimate	SE
$σ A int 2$	420 800	27960	420 400	28 004	416 800	27 696	416 000	27 692
$σ A sl 2$	11 096	2288	11 116	2320
$σ A v 2$	0.043	0.008			0.042	0.008
$ρ A int, A sl$	0.808	0.062	0.812	0.063
$ρ A int, A v$	0.627	0.073			0.608	0.0751
$ρ A sl, A v$	0.765	0.098
APHL	193 704		194 179		193 692		202 832
AIC	193 722		194 191		193 704		202 840

$σ A int 2$ = additive genetic variance of breeding value for intercept; $σ A sl 2$ = additive genetic variance of breeding value for slope (= macro-environmental sensitivity); $σ A v 2$ = additive genetic variance in environmental variance (= micro-environmental sensitivity); $ρ A int, A v$ = genetic correlation between breeding value for intercept and environmental variance; $ρ A int, A sl$ = genetic correlation between breeding values of intercept and slope of reaction norm; $ρ A sl, A v$ = genetic correlation between breeding values of slope and environmental variance; APHL = adjusted profile h-likelihood; AIC = Akaike’s information criterion; “Macro–micro” = model accounting for both macro- and micro-environmental sensitivities; “Macro” = model with only macro-environmental sensitivity; “Micro” = model with only micro-environmental sensitivity; “Simple” = model without macro- and micro environmental sensitivities and only a genetic effect for the phenotype; SE = approximate standard error obtained with ASReml.

ISSN: 1297-9686