**4.2 Thyrotropin releasing hormone receptor gene (***TRHR***)**

All the four *TRHR* polymorphisms studied existed in one LD block. Significant associations of porcine *TRHR* gene with head weight, carcass length, and electric conductivity, pH value, water holding capacity, intramuscular water and fat content of loin muscle were observed. QTLs of carcass length (Wimmers et al., 2002; Murani et al., 2006) and intramuscular fat content (de Koning et al., 1999) have been reported previously. Individuals with the haplotypes originating from the Pietrain had smaller head weight, longer carcass length and lower conductivity of loin muscle. However, no significant difference among the haplotypes was observed after bonferroni corrections.
