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This Article Full Text (PDF) All Versions of this Article: jas.2008-1417v1 87/5/1739    most recent Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Lum, G. E. Articles by Williams, C. C. Search for Related Content PubMed PubMed Citation Articles by Lum, G. E. Articles by Williams, C. C.

The influence of dietary selenium on common indicators of selenium status and liver glutathione peroxidase-1 mRNA

School of Animal Sciences, Louisiana State University Agricultural Center, Baton Rouge, Louisiana 70803

JRowntree{at}agcenter.lsu.edu

Abstract

The objective of this research was to determine the influence of dietary Se on various indicators of Se status and relative liver glutathione peroxidase 1 (GPx-1) mRNA levels in growing Holstein bull calves. Calves (n = 14, 7/diet) were started 28 d after birth on either a Se adequate (SeA) or Se deficient diet (SeD) and maintained on the diet until 180 d of age. Blood samples were taken from each calf for determination of erythrocyte GPx-1 and plasma GPx-3 activities and plasma Se concentration on d 28 of age, every 28 d thereafter, and at 180 d of age. To assess liver Se and GPx-1 mRNA, 3 calves were first euthanized at d 21 of age for baseline (BSL) measurements, and 4 calves from each treatment were euthanized at trial conclusion. Feed intake and ADG were not affected (P = 0.62) by dietary Se levels. However, liver Se concentration was higher (P < 0.05) for BSL calves and SeA calves than SeD calves, but no difference (P = 0.68) was observed between BSL calves and SeA calves. Plasma Se was higher for SeA calves (P < 0.01) than for SeD calves by d 56 of age. The GPx-1 activity was greater in SeA calves (P < 0.01) by d 84 of age, whereas GPx-3 activity was greater in SeA calves, but not until d 180 of age (P < 0.01). There was a 50% decrease in GPx-1 mRNA for the SeD calves (P < 0.05) compared with SeA calves. Thus, relative GPx-1 mRNA transcript level is reflective of Se status in the bovine. Furthermore, 152 d on a semi-purified, Se-deficient diet is adequate to create a Se deficiency in growing Holstein bull calves started on a Se-deficient diet at 28 d of age.

Key Words: calf • glutathione peroxidase • mRNA • selenium