title: Short communication: serum and tissue concentrations of vitamin D metabolites in beef heifers after buccal dosing of 25-hydroxyvitamin D3.
abstract: Sixteen crossbred (British x Continental; average un-shrunk body weight = 507.9 kg; SD = 45.6 kg) beef heifers fed a steam-flaked corn-based finishing diet with melengestrol acetate (0.4 mg/heifer daily) included to suppress estrus were used in a completely random design to evaluate the efficacy of buccal administration of 0, 10, 100, or 1000 mg of 25-hydroxyvitamin D3, (25-OH D3). Serum Ca, P, Mg, 25-OH D3, 1,25-dihydroxyvitamin D [1,25-(OH)2 D3], albumin, and protein were measured 24 h before dosing (-24 h), at dosing (0 h), and 6 and 24 h after dosing, after which the cattle were slaughtered at a commercial facility. Samples of kidneys, liver, longissimus lumborum, and triceps brachii were collected and evaluated for concentrations of 1,25-(OH)2 D3. With -24 and 0 h as baseline covariates, a significant time x treatment interaction was observed for serum 25-OH D3 and Ca concentrations, but not for serum 1,25-(OH)2 D3. Supplemental 25-OH D3 doses of 100 and 1000 mg significantly increased serum 25-OH D3 at 24 h after dosing, 1,25-(OH)2 D3 at 6 and 24 h after dosing, and serum Ca at 24 h after dosing. Similarly, buccal dosing of 1000 mg of supplemental 25-OH D3 significantly increased (approximately 2- to 3-fold) concentrations of 1,25-(OH)2 D3 in the kidney, liver, and longissimus lumborum relative to the other 3 treatments but not in triceps brachii. Serum albumin, protein, P, and Mg were not affected by treatment. Based on these results, buccal administration of 100 and 1000 mg 25-OH D3 increased vitamin D3 metabolites in serum and tissues, and it should be an effective method of delivering the vitamin.
authors.affiliation: Department of Animal and Food Sciences, Box 42141, Texas Tech University, Lubbock, 79409-2141, USA.
authors.forename: J D
authors.initials: JD
authors.lastname: Rivera
authors.forename: S E
authors.initials: SE
authors.lastname: Bachman
authors.forename: M E
authors.initials: ME
authors.lastname: Hubbert
authors.forename: M E
authors.initials: ME
authors.lastname: Branine
authors.forename: R L
authors.initials: RL
authors.lastname: Horst
authors.forename: S N
authors.initials: SN
authors.lastname: Williams
authors.forename: M L
authors.initials: ML
authors.lastname: Galyean
mesh_terms: D000278:Administration, Buccal; D000821:Animal Feed; D000818:Animals; D002417:Cattle / Q000097:blood / Q000378:metabolism*; D002762:Cholecalciferol / Q000008:administration & dosage / Q000378:metabolism / Q000493:pharmacokinetics; D004305:Dose-Response Relationship, Drug; D005260:Female; D007668:Kidney / Q000378:metabolism; D008099:Liver / Q000378:metabolism; D008460:Meat / Q000592:standards; D018482:Muscle, Skeletal / Q000378:metabolism; D011897:Random Allocation; D014807:Vitamin D / Q000008:administration & dosage* / Q000031:analogs & derivatives* / Q000097:blood / Q000378:metabolism* / Q000493:pharmacokinetics
chemical_list: D014807:Vitamin D; D002762:Cholecalciferol; C104450:25-hydroxyvitamin D