Broiler Chicken Carcass Composition and Meat Quality

At 56 days of age, blood was collected from the brachial vein of chickens by venipuncture using citrated syringes during a routine health inspection. At 93 days, chickens were weighed and killed by stunning and exsanguination, 12 h after feed was withheld. After the carcass composition traits were determined, meat quality traits were measured using methods previously described in detail [24 (link),46 (link),47 (link)]. The meat quality traits included subcutaneous fat thickness (SFT), AbFW, AbFP, DM_Br, DM_Th, IMF_Br, IMF_Th, pHu, DL, SF, and the color of muscle and skin, L*, a*, and b*. Samples from the breast muscle and abdominal fat tissues were snap-frozen in liquid nitrogen then held at −80°C until analysis of relative mRNA expression.