The Correlation between Polydactyly Phenotype and Product Quality of Beijing Fatty Chickens

[ Objective] This study aimed to investigate differences in product quality among Beijing fatty chickens with different polydactyly phenotypes. Based on the comparative analysis of production performance, egg quality and muscle quality characteristics, the correlation between polydactyly phenotype and product quali- ty of Beijing fatty chickens was analyzed, aiming at providing the reference for development and utilization of product quality and breeding of Beijing fatty chickens. [ Method] Egg laying/meat dual-purpose type Beijing fatty chickens were selected and divided into three groups （bilateral four-toed, unilateral five-toed and bilat- eral five-toed） with four replications, 60 chickens per replications, 240 chickens per group. The production performance （weight, laying rate and egg weight）, egg quality （Haugh unit） and muscle quality （pH, water-holding capacity, Warner-Bratzler shear force, TPA, nucleotide metabolites） characteristics of Beijing fatty chickens were determined. [ Result] The weight of 120-d-old and 240-d-old bilateral five-toed Beijing fatty chickens was slightly higher than that of bilateral fourtoed and unilateral five-toed Beijing fatty chickens, with no significant difference （P 〉0.05） ; egg weight of 160-d-old bilateral five-toed Beijing fatty chickens was significantly higher than that of bilateral four-toed and unilateral five-toed individuals （ P 〈 0.05 ）. Water-holding capacity of leg muscles of bilateral five-toed Bei- jing fatty chickens was significantly superior to that of unilateral five-toed and bilateral four-toed individuals （P 〈0.05 ）. The hardness, gumminess and chewiness of leg muscles of bilateral five-toed Beijing fatty chickens were significantly lower than that of unilateral five-toed and bilateral four-toed individuals （ P 〈 0.05 ）, but the coherence and elasticity were remarkably higher compared with unilateral five-toed and bilateral four-toed individuals （ P 〈 0.05 ）. Warner-Bratzler shear force of leg muscles of bilateral five-toed Beijing fatty chickens was significantly higher than that of other individuals （ P 〈 0.05 ）. There was no significant difference in flavor substances among Beijing fatty chickens with different polydactyly phenotypes （P 〉0.05）. [ Conclusion] At early stage, the weight and egg weight of fivetoed Beijing fatty chickens were slightly superior to that of four-toed individuals. In addition, Beijing fatty chickens with different polydactyly phenotypes displayed excellent muscle quality. Overall, leg muscle quality of Beijing fatty chickens exhibited a greater correlation with polydactyly phenotype than chest muscle quality.