Effect of Zinc Level and Source (Zinc Oxide Vs. Zinc Glycine) on Bone Mechanical and Geometric Parameters, and Histomorphology in Male Ross 308 Broiler Chicken

ABSTRACT The aim of this study was to evaluate the effect of adding zinc (Zn) mineral supplements from organic (ZnGly) and inorganic (ZnO) sources to growing male Ross 308 chickens on the mechanical, geometric, and histomorphometrical parameters of long bones. A corn-soybean meal basal diet was supplemented with Zn at 50 or 100 mg·kg-1 of a premix, except the control group (0 suppl). The serum concentration of insulin-like growth factor 1 was higher in the ZnGly50 group compared with the control group. Positive influence of Zn on the femur is highlighted when considering the significant increase in parameters such as mean relative wall thickness, and maximum elastic and ultimate strengths after Zn administration. Zinc supplementation did not affect tibial parameters. The histomorphometric analysis showed a positive impact of Zn supplementation (irrespective of source and level) on femoral trabecular thickness. Rapid loss in actual bone volume in tibial metaphyseal trabeculae was observed with ZnGly at 50 mg·kg-1. In conclusion, this study showed that dietary Zn supplementation positively influences bone mechanical properties, confirming its beneficial effect on the development of the skeletal system and bone tissue of broilers tested for a nutritional-osteoporotic factor. Adverse health effects in trabecular bone as a result of the use of Zn at 50 mg·kg-1 of the premix show that supplementing Zn at the recommended dose (100 mg·kg-1) is essential.