Organic zinc with moderate chelation strength enhances zinc absorption in the small intestine and expression of related transporters in the duodenum of broilers

Yun Hu; Chuanlong Wang; Wei Wu; Yicheng Qu; Weiyun Zhang; Ding Li; Ling Zhu; Feiyu Gao; Bingxin Wu; Liyang Zhang; Xiaoyan Cui; Tingting Li; Yanqiang Geng; Xugang Luo

doi:10.3389/fphys.2022.952941

Organic zinc with moderate chelation strength enhances zinc absorption in the small intestine and expression of related transporters in the duodenum of broilers

Front Physiol. 2022 Jul 22:13:952941. doi: 10.3389/fphys.2022.952941. eCollection 2022.

Authors

Yun Hu¹, Chuanlong Wang², Wei Wu¹, Yicheng Qu², Weiyun Zhang¹, Ding Li¹, Ling Zhu¹, Feiyu Gao¹, Bingxin Wu¹, Liyang Zhang², Xiaoyan Cui¹, Tingting Li¹, Yanqiang Geng¹, Xugang Luo¹

Affiliations

¹ Poultry Mineral Nutrition Laboratory, College of Animal Science and Technology, Yangzhou University, Yangzhou, China.
² Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, China.

Abstract

Our previous study demonstrated that the absorption of zinc (Zn) from the organic Zn proteinate with moderate chelation strength was significantly higher than that of Zn from the inorganic Zn sulfate in the in situ ligated duodenal segment of broilers, but the underlying mechanisms are unknown. The present study aimed to determine the effect of organic Zn with moderate chelation strength and inorganic Zn on the Zn absorption in the small intestine and the expression of related transporters in the duodenum of broilers. The Zn-deficient broilers (13 days old) were fed with the Zn-unsupplemented basal diets (control) containing 25.72 and 25.64 mg Zn/kg by analysis or the basal diets supplemented with 60 mg Zn/kg as the Zn sulfate or the Zn proteinate with moderate chelation strength (Zn-Prot M) for 26 days. The results showed that the plasma Zn contents from the hepatic portal vein of broilers at 28 days and 39 days of age were increased (p < 0.05) by Zn addition and greater (p < 0.05) in the Zn-Prot M than in the Zn sulfate. On d 28, Zn addition upregulated (p < 0.05) mRNA expression of zinc transporter 1 (ZnT1), Zrt-irt-like protein 5 (ZIP5), y + L-type amino transporter 2 (y + LAT2) and b^0,+-type amino acid transporter (rBAT), zinc transporter 4 (ZnT4) protein expression, and zinc transporter 9 (ZnT9) mRNA and protein expression in the duodenum. Moreover, ZnT9 mRNA expression, ZnT4, ZIP5, and rBAT protein expression, zinc transporter 7 (ZnT7), and y + LAT2 mRNA and protein expression in the duodenum of broilers on 28 days were higher (p < 0.05) in the Zn-Prot M than in the Zn sulfate. On d 39, supplemental Zn increased (p < 0.05) peptide-transporter 1 (PepT1) mRNA expression and y + LAT2 protein expression, while the mRNA expression of ZnT7 and Zrt-irt-like protein 3 (ZIP3) were higher (p < 0.05) for the Zn-Prot M than for the Zn sulfate in the duodenum. It was concluded that the Zn-Prot M enhanced the Zn absorption in the small intestine partially via upregulating the expression of ZnT4, ZnT7, ZnT9, ZIP3, ZIP5, y + LAT2, and rBAT in the duodenum of broilers.

Keywords: amino acid transporter; broiler; duodenum; the organic zinc with moderate chelation strength; zinc absorption; zinc transporter.