Assessment of Geometric Parameters of Tibiotarsal Bones in White Kołuda Geese Using Peripheral Quantitative Computed Tomography

The aim of the study was to evaluate geometrical parameters of tibiotarsal bones in geese depending on age, sex and place in the bone and conditions of breeding. The inner structure of tibiotarsal bones of White Kołuda® geese (W31) subjected to intensive breeding was analyzed using peripheral quantitative computed tomography (pQCT ). The analyzed bones were derived from birds representing five age groups: one-day-old as well as birds of 2, 4, 6 and 8 wk of age. Bones of 10 males and 10 females were isolated from each group. The analysis was conducted at two levels of the bone: the area of the proximal metaphysis and at half the length of the diaphysis. The proximal metaphysis was selected for the research as it had higher content of the cancellous bone than the distal metaphysis. It was known that the cancellous bone was characterized by a higher rate of metabolic changes. The following geometric parameters were determined: total bone area (TOT _A), trabecular area (TRAB _A), cortical area (CRT _A), cortical thickness (CRT _TH K_C), periosteal circumference (PERI C), endocortical circumference (ENDO _C) and Strength Strain Index (SSI ). It was found that 6 wk of life may be considered as critical in the postnatal development of geese. In the group of 6 wk males in the shafts of the tibial bones, there was a decrease in the values of the following parameters: TOT _A, TRAB _A, PERI _C, ENDO _C. Whereas in 8 wk, an attenuation of the values of all geometric parameters of tibiotarsal bones was observed in both sexes (with the exception of CRT _TH K_C), which may have a negative influence on bone resistance to fractures. In this period, a significant decrease in the values of geometric parameters of tibiotarsal bones could be observed, negatively affecting the resistance of the bone to fractures in 8 wk. The values of SSI parameter at the proximal metaphysis of the tibiotarsal bone decreased in both males and females in 8 wk. In turn, at mid-diaphysis, the SSI values decreased only in males in 8 wk. The achieved results and observations justify the use of optimal environmental and nutritional conditions in geese in order to improve the quality of their skeletal system and to minimize the risk of the occurrence of deformities and fractures of the pelvic limb during the breeding.