title: Organic and inorganic selenium: II. Transfer efficiency from ewes to lambs.
abstract: Adequate Se transfer from ewes to lambs is important to prevent Se-deficiency diseases. To evaluate how different chemical forms of Se administered at comparative dosages to mature ewes affect Se status of their lambs, 240 ewes were divided into 8 treatment groups (n = 30 each) and drenched weekly (at an amount equal to their summed daily intake) with no-Se (controls); at recommended amounts (4.9 mg of Se/wk) with inorganic Na-selenite, inorganic Na-selenate, or organic Se-yeast; or at supranutritional amounts (14.7 and 24.5 mg of Se/wk) with Na-selenite or Se-yeast for 1 yr. Weekly drenching of Se was effective at increasing (P < 0.002) Se concentrations in ewe colostrum and milk at 30 d of lactation and in improving (P < 0.001) the Se status of lambs (whole-blood and serum-Se concentrations at birth, and skeletal-muscle Se concentrations at 14 d of age). Selenium concentrations in lacteal secretions were greater in ewes drenched with Se-yeast (colostrum: 374, 436, and 982 ng/mL at 4.9, 14.7, and 24.5 mg of Se/wk, respectively; milk: 26, 39, 64 ng/mL) compared with ewes drenched with Na-selenite (colostrum: 204, 334, 428 ng/mL; milk: 16, 21, 24 ng/mL), and were also greater (P < 0.001) in their lambs. Selenium concentrations continued to increase (P < 0.001) in lamb whole blood (558 and 695 ng/mL at 14.7 and 24.5 mg of Se/wk, respectively), serum (126, 183 ng/mL), and skeletal muscle (991, 1,696 ng/mL) with supranutritional concentrations of Se-yeast, whereas Se concentrations did not differ in whole blood (304, 332 ng/mL), serum (77, 85 ng/mL), or skeletal muscle (442, 482 ng/mg) of lambs from ewes drenched with 14.7 or 24.5 mg of Se/wk of Na-selenite. We conclude that weekly oral drenching of ewes during gestation and lactation with organic Se-yeast results in a more efficient transfer of Se (over a wide range of supplementation rates) from ewe to lamb than does inorganic Na-selenite.
authors.affiliation: Department of Animal Sciences, College of Agriculture, College of Veterinary Medicine, Oregon State University, Corvallis 97331, USA.
authors.forename: W C
authors.initials: WC
authors.lastname: Stewart
authors.forename: G
authors.initials: G
authors.lastname: Bobe
authors.forename: W R
authors.initials: WR
authors.lastname: Vorachek
authors.forename: G J
authors.initials: GJ
authors.lastname: Pirelli
authors.forename: W D
authors.initials: WD
authors.lastname: Mosher
authors.forename: T
authors.initials: T
authors.lastname: Nichols
authors.forename: R J
authors.initials: RJ
authors.lastname: Van Saun
authors.forename: N E
authors.initials: NE
authors.lastname: Forsberg
authors.forename: J A
authors.initials: JA
authors.lastname: Hall
mesh_terms: D000818:Animals; D000831:Animals, Newborn / Q000378:metabolism*; D003126:Colostrum / Q000737:chemistry; D005260:Female; D007774:Lactation; D016018:Least-Squares Analysis; D008892:Milk / Q000737:chemistry; D018482:Muscle, Skeletal / Q000378:metabolism*; D011247:Pregnancy; D011446:Prospective Studies; D011897:Random Allocation; D064586:Selenic Acid; D018036:Selenium Compounds / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*; D012756:Sheep / Q000378:metabolism*; D018038:Sodium Selenite / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*
chemical_list: D018036:Selenium Compounds; D018038:Sodium Selenite; D064586:Selenic Acid