Simple Summary: Poultry breeding programs are established to ameliorate the genetic potential of
domestic birds through a selection process and crossbreeding programs. In this context, crossbreeding
has been considered as an essential tool to produce favorable genotypes, which are affected by
different genetic resources and non-genetic factors. Thus, the aim was to evaluate the impact
of crossing white and brown quail lines on growth performance, carcass traits, and the relative
expression of growth-related genes. The crossbred WBQ quail line (male white  female brown)
exhibited a significantly greater dressing percentage and better feed conversion ratio (FCR), as well
as higher mRNA expression of growth hormone receptor (GHR) and insulin-like growth factor-1
(IGF-1) genes.