2.4. Muscle distribution measurements

Six adult turkeys per strain, three males and three females, were dissected to obtain muscle masses. All dissected turkeys were a subset of those used in the growth portion of the study except the three domestic females. Muscles were dissected out at their origin and insertion points and weighed, with the tendons and aponeuroses included. Muscles were grouped by anatomical location, rather than function, to determine how regional mass distribution might affect the CoM position. The regions included the forelimb (mm. biceps brachii, scapulotriceps, humerotriceps, and coracotriceps), the trunk (mm. latissimus dorsi caudalis, supracoracoideus, and pectoralis), the proximal hind limb (mm. flexor cruris lateralis, iliofibularis, iliotibialis lateralis, and cranialis, femorotibialis, and iliofemoralis), and the distal hind limb (mm. peroneus, gastrocnemius lateralis and medialis, and tibialis cranialis). Because of the interest in regional mass, we selected some of the most massive muscles from each body region, as well as muscles from each group that performed a range of functions (flexion, extension, adduction, abduction). Therefore, relatively small muscles, such as the digital flexors, were not included. The sums of the muscle masses in each body region were divided by the total body mass to obtain a muscle mass to body mass ratio. The muscle group masses were also divided by the tibiotarsus length³ to address skeletal dimensional changes between strains.