Osseous development and tibial dyschondroplasia in five lines of turkeys.

Tibiotarsi and femurs from five genetic lines of turkeys from 8 to 39 weeks of age were examined to define the characteristics of normal bones. Bone lengths and body weights are presented. Tibial dyschondroplasia (TD) frequently was detected on gross examination and by high-detail radiography. The incidence of TD peaked at 12 weeks of age, when 79% of the toms were affected. This incidence rate dropped until the age of closure of the proximal tibial physis (22 to 24 weeks in toms) but remained 5 to 15%. Deformities of the tibiotarsi were frequently associated with TD in older toms. The incidence of TD and tibiotarsal deformities was highest in toms of the heaviest line.