Selenium supplementation can protect from enhanced risk of keel bone damage in laying hens exposed to cadmium

Abstract

The aim of this study was to investigate whether selenium (Se) supplementation can provide protection from an enhanced risk of keel bone damage (KBD) in laying hens due to the cadmium (Cd) toxicity associated with sub-chronic exposure. In this trial, based on the model of laying hens fed a diet supplemented with Se, Cd or Se + Cd in combination, the keel bone fractures and deviations, the bone mineral density (BMD), the serum biomarkers and the levels of twenty-eight elements were investigated. Consumption of feed added 150 mg kg⁻¹ CdCl₂ had a significant adverse effect on the keel bone, as determined by an increase in the percentage of keel bone damage, and a decrease in the BMD and the serum osteocalcin (OC). Supplementation with Cd led to disorders of mineral element metabolisms, including reduced concentrations of Si, K, Ca, Cr, Mn, Cu, Zn and Mo, and increased concentrations of Cd, and Pb (P < 0.05). Supplementation with 2 mg kg⁻¹ Na₂SeO₃ reduced keel bone damage, as well as the concentrations of toxic microelements Al and Pb. Se supplementation during 13 weeks of exposure to Cd partially prevented Cd-induced increase rates of the keel bone fracture and decrease concentrations of OC. Moreover, the Se + Cd co-treatment alleviated the degree of changes in K, Ca, Cr, Cu, Zn, Cd and Pb concentrations which in contrast were induced by Cd (P < 0.05). These results support the conclusion that enhanced Se supplementation during sub-chronic Cd exposure can, at least partially, reduce keel bone damage. This protective effect may result from maintenance of homeostasis of the elements in bones of laying hens.