Gene Effects on Body Weight, Carcass Yield, and Meat Quality of Thai Indigenous Chicken.

The selection of rapidly growing animals in breeding programs has had inadvertent detrimental effects on meat quality. Thus, the aim of the present study was to investigate the relationship between body weight (BW) and meat quality traits, and the effects of genes encoding insulin-like growth factor I (), insulin-like growth factor II (), melanocortin-4 receptor (), and calpain 1 () on BW, carcass yield, and meat quality of the Thai indigenous chicken, Leung Hang Khao. Five hundred and ten chickens were used for genotyping. PCR-restriction fragment length polymorphism and PCR-single strand conformation polymorphism were used to determine the genotypes of , and . BWs were collected from 0-16 weeks of age. The chickens were sacrificed at 16 weeks and individual carcass yields and meat qualities (drip loss, cooking loss, and shear force) were recorded. The correlations between BW and meat qualities were determined. Significant correlation between BW and cooking loss and shear force of breast meat and between BW and drip loss of thigh meat were detected (<0.05); however, the magnitude of the association was low (-0.1-0.1). was eliminated from the association analysis because genotype was lost and the frequency of occurrence of the genotype was low (0.04). Significant associations between , and BW, and and meat quality were detected, while non-significant association between and BW was observed. The results indicated a low, negative relationship between BW and meat quality, and that the and could be used as genetic markers in Leung Hang Khao chickens to improve growth and meat quality through breeding.