Transcriptomic analysis of thigh muscle of Lueyang black-bone chicken in free-range and caged feeding.

Lueyang black-bone chicken is free-range in hilly areas and has unique genetic characteristics and excellent muscle quality. However, the molecular mechanisms of breeding mode influence growth and meat quality in Lueyang black-bone chicken are still unclear. Here we analyzed the meat quality and transcriptome data of thigh muscle by comparing free-range and caged modes at the age of 60 and 120 days in Lueyang black-boned chicken. The results demonstrated that the free-range mode could improve the pH value, tenderness, and reducing the hardness of the thigh muscle. Intramuscular fat (IMF) content of the thigh muscle was markedly higher in the caged chickens compared with free-range animals at the age of 60 days. Functional pathway analysis illustrated that tight junction signaling was associated with the formation of slow-twitch fibers in free-range chickens at age of 120 days. All research data proved that the free-range mode could improve muscle quality by promoting the formation of slow-twitch fibers and IMF in thigh muscle in Lueyang black-bone chicken. Based on the animal benefit and healthy, the free-range feeding should be considered during the breeding process of broiler chicken. The results provide good knowledge of the functional molecular mechanisms associated with muscle quality in Lueyang black-bone chicken.