Ti is the fixed effect of
the ith treatment; Gg is the fixed effect of the gth gene; SWm and SAm
are the effects of the slaughter weight and the slaughter age of the
mth animal included as covariates; Sim is the random effect of the biological
sample (Sim ~ Ν(0, σ2
S)); Am is the random effect of the animal
from where the samples were collected (Am ~ Ν(0, σ2
S)); TGgi is the random interaction
effect among the ith treatment in the expression of the gene g (TGgi ~ Ν(0, σ2
TG)), and egim is the random residual. Gene specific
residual variance (heterogeneous residual) was fitted to the gene by
treatment effect (egim ~ N(0, σ2
eig)).