Neonatal testis transcriptome profiles differ among calves born to cows supplemented with different forms of dietary selenium throughout gestation

In many parts of the US, selenium (Se)-deficient soils dictate the necessity of supplementing this trace mineral directly to the diet of cattle, with the form of Se supplied known to affect tissue-level gene expression profiles and presumably function. Because a deficiency of Se will reduce fertility, including reduced biosynthesis of testosterone by the testis and an increased frequency of abnormalities in mature spermatozoa, we hypothesized that the form of Se supplemented to cows during gestation would affect the transcriptome of the neonatal bull calf testis. Microarray analysis using the Bovine gene 1.0 ST array (GeneChip; Affymetrix, Inc., Santa Clara, CA) was conducted to determine whether gestational form of supplemental Se affected gene expression profiles in the testis. GeneChip transcript annotations were last updated in January 2013 using the annotation update release 33 from the NetAffx annotation database. Twenty-four Angus cross cows were assigned randomly (n=8) to individual ad libitum intake of a common vitamin-mineral mix that contained 35 ppm of Se supplied as either inorganic (ISe, sodium selenite; Prince Se Concentrate, Prince Agri Products, Inc., Quincy, IL), organic (OSe, Sel-Plex; Alltech Inc., Nicholasville, KY), or a 50/50 mix of ISe/OSe (Mix) Se for 4 months prior to breeding and throughout gestation. Cows were managed under a fall-calving, forage-based, cow-calf production regimen at the University of Kentucky Princeton Research and Education Center. Testis tissue (ISe n=5; OSe n=4; Mix n=4) was collected within 2 days of birth, and RNA extracted for microarray analysis.