@article{KuhlAurichWulfetal.2012,
  author    = {Kuhl, Juliane and Aurich, J{\"o}rg E. and Wulf, Manuela and Hurtienne, A. and Schweigert, Florian J. and Aurich, Christine},
  title     = {Effects of oral supplementation with beta-carotene on concentrations of beta-carotene, vitamin A and alpha-tocopherol in plasma, colostrum and milk of mares and plasma of their foals and on fertility in mares},
  series = {Journal of animal physiology and animal nutrition},
  volume    = {96},
  journal   = {Journal of animal physiology and animal nutrition},
  number    = {3},
  publisher = {Wiley-Blackwell},
  address   = {Malden},
  issn      = {0931-2439},
  doi       = {10.1111/j.1439-0396.2011.01150.x},
  pages     = {376 -- 384},
  year      = {2012},
  abstract  = {In this study, effects of oral beta-carotene supplementation to mares (beta-carotene group: 1000 mg/day, n = 15; control group: n = 15) from 2 weeks before foaling until 6 weeks thereafter on concentrations of beta-carotene, vitamin A and a-tocopherol in plasma, colostrum and milk and plasma of their foals were determined. In addition, effects on fertility were studied. Beta-carotene concentrations increased in plasma and colostrum of beta-carotene-supplemented mares compared to control mares (p < 0.05). In mares of both groups, beta-carotene concentrations were higher in colostrum than in milk (p < 0.05). In foals, beta-carotene concentrations increased with colostrum uptake and were higher in foals born to supplemented mares (p < 0.05; control group: 0.0003 +/- 0.0002 mu g/ml on day 0, 0.008 +/- 0.0023 mu g/ml on day 1; beta-carotene group: 0.0005 +/- 0.0003 mu g/ml on day 0, 0.048 +/- 0.018 mu g/ml on day 1). Concentrations of vitamin A and a-tocopherol were higher in colostrum than in milk (p < 0.05) but did not differ between groups. Concentration of a-tocopherol in plasma of mares decreased over time and in foals, increased markedly within 4 days after birth. All but one mare (control group) showed oestrus within 2 weeks post-partum. Occurrence of oestrus did not differ between groups. More mares of the control group (7/7 vs. 5/12 in the beta-carotene group) became pregnant after being bred in first post-partum oestrus (p < 0.05). In conclusion, beta-carotene supplementation to mares increased beta-carotene concentrations in plasma, colostrum and milk of mares and plasma of their foals but had no positive effects on fertility.},
  language  = {en}
}
@article{MuellerRailaAltenkampetal.2012,
  author    = {Mueller, K. and Raila, Jens and Altenkamp, Rainer and Schmidt, D. and Dietrich, R. and Hurtienne, Andrea and Wink, M. and Krone, O. and Brunnberg, Leo and Schweigert, Florian J.},
  title     = {Concentrations of retinol, 3,4-didehydroretinol, and retinyl esters in plasma of free-ranging birds of prey},
  series = {Journal of animal physiology and animal nutrition},
  volume    = {96},
  journal   = {Journal of animal physiology and animal nutrition},
  number    = {6},
  publisher = {Wiley-Blackwell},
  address   = {Hoboken},
  issn      = {0931-2439},
  doi       = {10.1111/j.1439-0396.2011.01219.x},
  pages     = {1044 -- 1053},
  year      = {2012},
  abstract  = {This study investigated vitamin A compounds in the plasma of healthy free-ranging Central European raptors with different feeding strategies. Plasma samples of nestlings of white-tailed sea eagle [white-tailed sea eagle (WTSE), Haliaeetus albicilla) (n = 32), osprey (Pandion haliaetus) (n = 39), northern goshawk (Accipiter gentilis) (n = 25), common buzzard (Buteo buteo) (n = 31), and honey buzzard (Pernis apivorus) (n = 18) and adults of WTSE (n = 10), osprey (n = 31), and northern goshawk (n = 45) were investigated with reversed-phase-high-performance liquid chromatography (RP-HPLC). In WTSE, northern goshawks and common buzzards retinol were the main plasma component of vitamin A, whilst in ospreys and honey buzzards, 3,4-didehydroretinol predominated. The median of the retinol plasma concentration in the nestlings group ranged from 0.12 to 3.80 mu M and in the adult group from 0.15 to 6.13 mu M. Median plasma concentrations of 3,4-didehydroretinol in nestlings ranged from 0.06 to 3.55 mu M. In adults, northern goshawks had the lowest plasma concentration of 3,4-didehydroretinol followed by WTSE and ospreys. The plasma of all investigated species contained retinyl esters (palmitate, oleate, and stearate). The results show considerable species-specific differences in the vitamin A plasma concentrations that might be caused by different nutrition strategies.},
  language  = {en}
}