Feed efficiency is an important trait in the swine industry, but it is difficult to measure individually for genetic improvement. A total of 184 commercial pigs (50% Duroc, 25% Large White, and 25% Landrace) were collected for blood and genotyped. The average daily gain, daily feed intake (DFI), feed conversion ratio (FCR), gain per feed (G/F) and residual feed intake (RFI) were used in the analysis. The PCR-RFLP was used for the genotyping of candidate gene markers. The associations of gene polymorphism (cholecystokinin type A receptor (CCKAR), melanocortin 4 receptor (MC4R), leptin gene (LEP), porcine cathepsin with feed efficiency and growth traits in commercial pigs were investigated. The AA genotype of MC4R was significantly associated with the DFI at P=0.01. The polymorphism in porcine cathepsin D (CTSD) and cathepsin Z (CTSZ) were significantly associated with FCR, G/F, and RFI at P<0.05. The low FCR was associated with GG genotype in CTSZ and CTSD.
