Dose–responses of zinc as zinc–methionine supplements on antioxidant status, hematological parameters, immune response and the expression of IL-4 and IL-6 genes of ewes in the hot season

Abstract

This study was implemented to evaluate the effects of different zinc doses as Zinc-Met supplement (Zinpro^®) on the antioxidant status, blood immune cells, antibody titers, and the expression of IL-4 and IL-6 genes of ewes in the hot season. In a completely randomized design, 24 ewes were assigned to treatments as follow: 0, 15, 30 and 45 mg/kg zinc as Zinc-Met supplementation for 40 days in region with 40 °C and vaccinated against food-and-mouth disease as an immune challenge at day 30, and then blood samples were collected on day 40. Ewes were fed a basal diet containing 29.9 mg zinc/kg. The highest activity of the antioxidant enzyme and the lowest lipid peroxidation values were found in ewes receiving 30 and 45 mg/kg zinc following a linear trend. The highest lymphocytes count and antibody titers were found in ewes received 30 mg zinc/kg. There were no significant differences among treatments for the relative expression of genes. In overall, zinc supplementation non-significantly up-regulate interleukin-4 and down-regulate interleukin-6. It was concluded that zinc supplementation as Zinc-Met could enhance the antioxidant status and immune response of ewes under heat stress; supplementation of diet with 30 mg zinc/kg (300 mg/kg Zinpro^®) appeared to be the most effective dose.

Keywords:

• Antibody titer
• blood cells
• cytokine
• foot-and-mouth disease
• heat stress

Acknowledgments

The authors thank the Deputy of Research in Islamic Azad University, Science and Research Branch for their help in approving and preparing laboratory materials and equipment. Also authors thank the Nuclear Science and Technology Research Institute and Dr. Parvin Shawrang for their cooperation and generous assistance in carrying out this research project. This paper was elicited from PhD thesis (Matin Jamei), Science and Research Branch, IAU.

Authors’ contributions

AAS: Supervision, Reviewing and Editing, JM: Investigation, Data curation, Writing, MC: Visualization, Validation. All authors know and agree with the final version of the manuscript.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability Statement

The data presented in this study are available upon request from the corresponding author.

Additional information

Funding

The author(s) reported there is no funding associated with the work featured in this article.