Short communication: serum and tissue concentrations of vitamin D metabolites in beef heifers after buccal dosing of 25-hydroxyvitamin D3

• Published in: Journal of dairy science Vol. 88; no. 4; p. 1364
• Main Authors: Rivera, J D, Bachman, S E, Hubbert, M E, Branine, M E, Horst, R L, Williams, S N, Galyean, M L
• Format: Journal Article
• Language: English
• Published: United States 01-04-2005
• Subjects: Administration, Buccal; Animal Feed; Animals; Cattle - blood; Cattle - metabolism; Cholecalciferol - administration & dosage; Cholecalciferol - metabolism; Cholecalciferol - pharmacokinetics; Dose-Response Relationship, Drug; Female; Kidney - metabolism; Liver - metabolism; Meat - standards; Muscle, Skeletal - metabolism; Random Allocation; Vitamin D - administration & dosage; Vitamin D - analogs & derivatives; Vitamin D - blood; Vitamin D - metabolism; Vitamin D - pharmacokinetics
• ISSN: 0022-0302
• DOI: 10.3168/jds.S0022-0302(05)72803-4

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.