The effect of feed supplementation with zinc chelate and zinc sulphate on selected humoral and cell-mediated immune parameters and cytokine concentration in broiler chickens

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

“…The use of this type of zinc compound as a feed additive makes it possible to administer smaller doses and to ensure proper assimilation of the zinc by the birds, leading to improved performance parameters. Nevertheless, an excessive supply of zinc glycine chelates together with phytase may stimulate cellular immune mechanisms by increasing the proliferation of T lymphocytes and immune reactivity [6]. Our previous work indicates that an excessive supply of zinc leads to increased concentrations of IL-2, TNF-α, and IL-10, which regulate homeostasis in the body and take part in the development of the local immune process within the intestines [6].…”

“…Nevertheless, an excessive supply of zinc glycine chelates together with phytase may stimulate cellular immune mechanisms by increasing the proliferation of T lymphocytes and immune reactivity [6]. Our previous work indicates that an excessive supply of zinc leads to increased concentrations of IL-2, TNF-α, and IL-10, which regulate homeostasis in the body and take part in the development of the local immune process within the intestines [6]. Our research has also shown that the use of zinc sulfate can lead to a local inflammatory response in the intestines, as evidenced by the high concentration of pro-inflammatory cytokines in the birds receiving zinc in this form [6].…”

“…Furthermore, feed supplementation with a zinc glycine chelate (Zn-Gly) together with phytase was shown to exert a similar effect on poultry, but on a smaller scale [6]. However, we could not rule out microdamage to the intestinal epithelium as a consequence of an excessive supply of these compounds.…”

“…In addition, endogenous losses of zinc are linked to disturbances in intestinal absorption and increased excretion of the element. Zinc deficiency in poultry manifests as impaired resistance and thus increased susceptibility to disease and can lead to debilitation and death [6]. Supplementation of poultry feed with various forms of zinc, usually inorganic forms such as sulfates and oxides, has been recommended [11].…”

“…Kidd et al [15,16] recommended the use of organic forms of zinc. Zinc chelates, including glycine chelates, have better bioavailability than inorganic forms of zinc [6]. In addition, Kidd et al [15,16] have suggested that dietary Zn from organic sources may be absorbed intact and function differently after absorption than Zn from inorganic sources.…”