USE OF DEXA TO EVALUATE INFLUENCE OF DIETARY AND ENVIRONMENTAL MANAGEMENT IN Testudo hermanni

ABSTRACT: In chelonians differences in bone mineralization have been related with variation of diet and management (Fledelius et al., 2005; Liesegang et al., 2007; Liesegang et al., 2001). In order to assess bone mineral content and bone mineral density, the Dual-Energy X-ray Absorptiometry (DEXA) is the technique of choice in human and veterinary medicine (Lauten et al., 2001; Zotti et al., 2004). The aim of our study is to optimize DEXA technique to evaluate differences in mineralization in hatchling Hermann's tortoises, related with diet and management. For this purpose twenty-six recently hatched Hermann's tortoises were randomly divided in three groups. Group 1 was kept outside, hibernated for 6 months, and fed only on the natural enclosure vegetation of grasses. Group 2 and group 3 were raised under artificial conditions, with constant photoperiod and temperature. Group 2 was fed the same grasses of the first group. Group 3 diet was composed by plants of Cichorium spp. intended for human consumption. No mineral supplementation was offered. After 1 year DEXA was performed through a mouse densitometer (Lunar Piximus GE Healthcare). Bone mineral density (BMD, g/cm2) and bone mineral content (BMC, g) were determined of a total body region of interest (ROI), a ROI on the spine, and a ROI on the caudal skeleton. Statistical analysis was performed using One-Way ANOVA followed by Tukey HSD Test. Regression equations of data were estimated (Fig 1). Statistically significant differences between the total body ROI were found: BMD (0.0633 vs 0.1001 vs 0.1019g/cm2; P=0.0017); BMC (0.9522 vs 2.6607 vs 3.0678g; P=0.0039). These findings allowed us to evaluate how diet and husbandry influence mineralization of specific anatomic site.