Microstructure and mineral content of femora in male turkeys with and without fractures.

Microscopic and radiographic observations, as well as ash, calcium, phosphorus, copper, manganese, and zinc concentrations, were evaluated from femora of 32- to 35-wk-old male turkeys from two different farms (A and B). Turkeys from Farm A were divided into birds with femoral fracture (AF) and without femoral fracture (ANF). Turkeys from Farm B did not have femoral fractures (BNF). In the mid-diaphyseal cortex of turkeys without femoral fractures, collagen fibers were evenly distributed parallel to the transverse plane of bone surface. In contrast, collagen fibers were disorganized and the cortex was osteoporotic in turkeys with femoral fractures. Each turkey with femoral fractures also had callus on the mediocaudal region of the femoral middiaphysis. The periosteal callus was interrupted at the insertion of the puboischiofemoralis muscle. Muscle attachment to the bone might have interfered with the formation of periosteal callus. The concentration of calcium was lower in the cortex of turkeys in group AF compared to turkeys in groups ANF and BNF. The focal nature of the callus, along with the low levels of calcium, is indicative of a local repair response with alteration in cortical structure and altered concentrations of minerals in the cortex. These changes in the bone and the routine handling of the birds might have predisposed the turkeys to complete fractures of the femur.