The influence of dietary selenium on common indicators of selenium status and liver glutathione peroxidase-1 messenger ribonucleic acid.
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) messenger RNA (mRNA) levels in growing Holstein bull calves. Calves (n = 14, 7/diet) were started 28 d after birth on 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 killed at d 21 of age for baseline (BSL) measurements, and 4 calves from each treatment were killed at trial conclusion. Feed intake and ADG were not affected (P = 0.62) by dietary Se concentrations. However, liver Se concentration was greater (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 greater 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, SeD diet is adequate to create a Se deficiency in growing Holstein bull calves started on a SeD diet at 28 d of age.
Lum
G E
GE
School of Animal Sciences, Louisiana State University Agricultural Center, Baton Rouge 70803, USA.
Rowntree
J E
JE
Bondioli
K R
KR
Southern
L L
LL
Williams
C C
CC
D000818:Animals; D000831:Animals, Newborn; D002417:Cattle / Q000378:metabolism*; D004032:Diet; D019587:Dietary Supplements; D005979:Glutathione Peroxidase / Q000378:metabolism*; D008099:Liver / Q000737:chemistry* / Q000201:enzymology*; D008297:Male; D012333:RNA, Messenger / Q000378:metabolism*; D011897:Random Allocation; D012643:Selenium / Q000032:analysis / Q000172:deficiency* / Q000378:metabolism*; D013997:Time Factors; D000094765:Glutathione Peroxidase GPX1
D012333:RNA, Messenger; D005979:Glutathione Peroxidase; D012643:Selenium; D000094765:Glutathione Peroxidase GPX1