Skeletal and tendon lesions of male broiler-breeders reared on elevated slats

Eighty 25-week-old male broiler-breeder chickens were placed in pens with elevated slats for 16 weeks. A similar group of birds was housed on floor pens for comparison. The coxofemoral, stifle, and tibiotarsal joints and their supporting tendons and ligaments were examined grossly. Rearing heavy broiler-breeders on elevated slats did not result in grossly apparent arthritis, tendonitis, or tendon failure. Body weights and shank lengths and diameters were not markedly different. Microscopically, the broiler-breeders reared on slats had a lymphocytic synovitis with synovial cell hyperplasia involving the gastrocnemius and digital flexor tendons. The incidence and severity of the lesion increased with time.