Feeding Preferences, Carcass Characteristics, and Plasma and Pectoral Muscle Biochemical Indicators in Racer and...

Racer pigeons are renowned for their exceptional flying abilities, and Shiqi pigeons are meat pigeons prized for their tender and nutritious meat. This study investigated the physiological and metabolic differences between the two breeds under distinct breeding objectives by examining their feeding habits, carcass performance, meat quality, and intestinal development, thereby providing insights for pigeon breeding programs. Six racer and six Shiqi pigeons, each aged 28 d, were selected. They were fed a basal diet until 35 d of age, after which they were slaughtered for testing. Racer pigeons had substantially lower daily feed and pellet intake than Shiqi pigeons. There was no difference in the proportion of the major grains consumed. Slaughter traits, including live, carcass, semi-eviscerated weights, and weights of the spleen, gizzard, and bursa of Fabricius were substantially lower in racer pigeons. Racer pigeons had substantially higher pectoral muscle redness and yellowness at 45-min post-slaughter but lower pH values at 45 min and 24 h. Racer pigeons had substantially higher plasma GSH-Px activity and glucose concentrations. Racer pigeons had a higher pectoral muscle triglyceride (TG) content, greater duodenal weight and length, higher duodenal villus-to-lumen ratio, and elevated catalase (CAT) activity. However, they had a lower pectoral muscle GLU content and reduced jejunal weight and length. Compact racer pigeons are physiologically adapted for flight and are characterized by a strong antioxidant capacity and a well-developed duodenum. In contrast, the larger Shiqi pigeon, with a more developed jejunum and heavier pectoral muscles, was optimized for digestion and meat yield. These distinct profiles highlight the strong influence of genetic selection; the identified metrics offer valuable insights into targeted breed development.