Project description:Selenium (Se) is an essential nutrient for beef cattle health and commercial production. The molecular mechanisms responsible for the physiological responses of the animal to dietary Se supplementation, however, have not been evaluated. Furthermore, the potential effect of two chemical forms (organic vs. inorganic) of Se on gene expression by Se-sufficient cattle has not been evaluated. Microarray analysis using the GeneChip Bovine Genome Array (Affymetrix, Inc., Santa Clara, CA) was conducted to determine if dietary Se supplementation in organic vs. inorganic form (OSe vs. ISe) differentially affects the liver gene expression profile in growing beef heifers.
Project description:Selenium (Se) is an essential nutrient for beef cattle health and commercial production. The molecular mechanisms responsible for physiological responses of the animal to dietary Se supplementation, however, have not been evaluated. Furthermore, the potential effect of two chemical forms (organic vs. inorganic) of Se on gene expression by Se-sufficient cattle has not been evaluated. Microarray analysis using the GeneChip Bovine Genome Array (Affymetrix, Inc., Santa Clara, CA) was conducted to determine if dietary Se supplementation in organic vs. inorganic form (OSe vs. ISe) differentially affects the liver gene expression profile in growing beef heifers. Sodium selenite (Prince Se Concentrate; Prince Agri Products, Inc., Quincy, IL) was used as the source of ISe form. Se-enriched yeast (Sel-Plex; Alltech, Inc., Nicholasville, KY) was used as the source of OSe form. Thirty Angus heifers (BW 393 ± 9 kg) were randomly assigned to 3 dietary treatments (n = 10): Control (Ctrl) group received no dietary Se supplementation; ISe treatment group daily received dietary supplementation of Se at 3 mg/animal from ISe source; OSe treatment group daily received dietary supplementation of Se at 3 mg/animal from OSe source. Six animals were randomly selected from each of 3 treatment groups for RNA extraction and microarray analysis.
Project description: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.
Project description: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.
Project description:The potential for dietary supplementation with n-3 polyunsaturated fatty acids (n-3 PUFA) to improve reproductive efficiency in cattle has received much interest. The mechanisms by which n-3 PUFA may affect physiological and biochemical processes in key reproductive tissues are likely to be mediated by significant alterations in gene expression. We used microarrays to assess endometrial gene expression on day 17 of the estrous cycle in n-3 PUFA compared with control fed heifers. Beef heifers were supplemented with a rumen protected source of either a saturated fatty acid (CON; palmitic acid) or high n-3 PUFA (n-3 PUFA; 275 g) diet per animal per day for 45 days and global gene expression was determined in uterine endometrial tissue using an Affymetrix® oligonucleotide bovine array.