Nano-selenium Supplementation Increases Selenoprotein (Sel) Gene Expression Profiles and Milk Selenium Concentration in Lactating Dairy Cows

Liqiang Han,Tengyun Gao,Kun Pang,Tong Fu,Clive J C Phillips

doi:10.1007/s12011-020-02139-2

Abstract

Supplementation with selenium is common for dairy cows, but the importance of selenium source is not clear. This study aimed to compare nano-selenium (Nano-Se) and sodium selenite supplements for dairy cows on lactation performance, milk Se levels and selenoprotein (Sel) gene expression. Twelve multiparous Holstein cows were randomly divided into two groups: a control group fed a basal diet plus 0.30 mg Se/kg of DM as sodium selenite or Nano-Se for 30 days. Dry matter intake, milk yield and composition were not affected by dietary Se source (P > 0.05); however, the milk total Se levels and milk glutathione peroxidase (GSH-Px) activities were higher with Nano-Se supplementation than sodium selenite (P < 0.05). At the end of the experiment, Nano-Se supplementation significantly increased plasma Se levels and GSH-Px activity, compared with the sodium selenite supplement. The mRNA expression levels of glutathione peroxidase 1, 2 and 4; thioredoxin reductase 2 and 3; and selenoproteins W, T, K and F were markedly upregulated (P < 0.05) in the mammary gland of the Nano-Se group. Thus, the source of selenium plays an important role in the antioxidant status and in particular the Sel gene expression in the mammary glands of dairy cows, both being stimulated by nano sources.

Highlights

Selenium (Se) is a trace element nutrient that acts as a cofactor of antioxidant enzymes and Liqiang Han and Kun Pang contributed to this work.Milk potentially makes an important contribution to a person’s daily intake of Se, as consumption of 100 g milk/day will provide at least 10% of the daily Se requirement for adults [7]
The aim of this work was to evaluate the effects of Nano-Se supplementation on lactation performance, milk Se concentration and mammary Sel expression in mid-lactation dairy cows in comparison with conventional sodium selenite
Our results showed that Nano-Se was more effective than inorganic Se at increasing the milk Se concentration

Summary

Introduction

Selenium (Se) is a trace element nutrient that acts as a cofactor of antioxidant enzymes (such as glutathione peroxidases) and Liqiang Han and Kun Pang contributed to this work.Milk potentially makes an important contribution to a person’s daily intake of Se, as consumption of 100 g milk/day will provide at least 10% of the daily Se requirement for adults [7]. Supplements of dietary Se to increase milk Se content have been developed in cows [8]. Nano-Se contains more active centres than conventional Se products, with higher biological activity and lower toxicity, and is more effective at increasing selenoprotein (Sel) expression [14,15,16]. It has been reported that Nano-Se supplementation had higher Se deposition efficiency than sodium selenite in laying hens [15]. Information on the effects of Nano-Se supplementation on bovine lactation performance and milk Se is limited. The aim of this work was to evaluate the effects of Nano-Se supplementation on lactation performance, milk Se concentration and mammary Sel expression in mid-lactation dairy cows in comparison with conventional sodium selenite

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