Hepatic transcriptome profiles differ among maturing beef heifers supplemented with different forms of dietary selenium

Little is known regarding the relationship between Selenium (Se) concentrations in the liver and liver gene expression. Because most cow-calf operations in Se-poor soils provide enough Se in mineral mixes to avoid deficiency, the aim of this study was to determine the effects of 4 Se form supplementation strategies (none or inorganic, organic, or 1:1 inorganic:organic mix) on liver gene expression profiles using a Se-adequate model. Microarray analysis was conducted using the custom WT Btau 4.0 Array (version 1; GeneChip, Affymetrix, Inc., Santa Clara, CA, USA) to determine if dietary Se supplementation form differentially affects the hepatic gene expression profiles of maturing beef heifers. Sodium selenite was used as the source of inorganic Se and Se-enriched yeast was the source of organic selenium. Thirty-six Angus heifers (BW 400 ± 9.0 kg) were ranked on the Se concentration of their biopsied (day -14) liver sample and randomly assigned to one of four dietary Se treatments: Control (Ctrl) group received no exogenous dietary Se supplementation; inorganic (ISe) treatment group received daily dietary Se supplementation at 3 mg/ animal of the ISe form; organic (OSe) treatment group received daily dietary Se supplementation of 3 mg/ animal of OSe form; and the mix (1:1 ISe:OSe) received daily dietary Se supplementation of 3 mg/ animal of 50:50 mix of ISe and OSe forms. RNA was extracted from biopsied liver samples taken 168 days after initiation of Se supplementation and microarray analyses were conducted.