Effect of Zinc Sulfate and Zinc Glycine Chelate on Concentrations of Acute Phase Proteins in Chicken Serum and Liver Tissue

The aim of the study was to determine how inorganic and organic forms of zinc affect the concentrations of C-reactive protein (CRP), serum amyloid A (SAA), alpha-1-acid glycoprotein (α-1-AGP), haptoglobin (Hp), and transferrin (TRF) in the blood and liver tissue of 450 1-day-old Ross 308 chicken. Four experimental groups received one the following: inorganic zinc (ZnSO₄), a zinc phytase enzyme supplement (ZnSO₄-F), organic zinc in combination with glycine (Zn-Gly), or organic zinc supplemented with phytase (Zn-Gly-F). The chicken serum and liver homogenates were assayed using an ELISA kit. The results of the study showed statistically significantly higher serum and liver concentration of SAA in the group of birds that received zinc sulfate in comparison to the group of birds receiving zinc in organic form. A statistically significantly higher serum concentration of CRP and α-1-AGP was also noted in the group receiving zinc sulfate as compared to the Zn-Gly group. Comparison of the serum concentration of TRF between the supplemented groups showed a statistically significant increase in this parameter in the Zn-Gly-F group as compared to the ZSO₄-F group. The increase in the serum concentration of Hp in all groups in comparison to the control may indicate stimulation of local immune mechanisms. The results of this study showed an increase in the concentrations of APPs such as AGP and TRF following the administration of zinc glycine chelates, which may demonstrate their effect on metabolic processes in the liver and on immunocompetent cells that regulate the intensity of the immune response.