Effect of Magnesium Administration Route on Plasma Minerals in Holstein Calves Receiving Either Adequate or Insufficient Magnesium in Their Diets

• Published in: Journal of dairy science Vol. 73; no. 2; pp. 470 - 473
• Main Authors: Bacon, J.A., Bell, M.C., Miller, J.K., Ramsey, Nancy, Mueller, F.J.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.02.1990; Am Dairy Sci Assoc; American Dairy Science Association
• Subjects: ADMINISTRACION; ADMINISTRATION; Administration, Oral; Administration, Rectal; Animals; BLOOD PLASMA; BOCA; BOUCHE; BREEDS; Calcium - blood; CALVES; Cattle; Cattle Diseases - drug therapy; Cattle Diseases - prevention & control; DIET; DIETA; HIPOMAGNESEMIA; HOLSTEIN-FRIESIAN; HYPOMAGNESAEMIA; hypomagnesemia; HYPOMAGNESIEMIE; INTESTIN; INTESTINES; INTESTINOS; MAGNESIO; MAGNESIUM; Magnesium - administration & dosage; Magnesium - blood; Magnesium Deficiency - complications; Magnesium Deficiency - drug therapy; Magnesium Deficiency - veterinary; Male; MOUTH; PLASMA SANGUIN; PLASMA SANGUINEO; Potassium - blood; RACE; RAZAS; REGIME ALIMENTAIRE; TERNERO; Tetany - etiology; Tetany - prevention & control; Tetany - veterinary; VEAU; hypomagnesemia; magnesium; calves
• ISSN: 0022-0302; 1525-3198
• DOI: 10.3168/jds.S0022-0302(90)78693-6

Rates of increase in plasma Mg following rectal or oral administration of solutions containing 30g MgCl2·6H2O were compared in 10 Holstein bull calves receiving wheat straw (.07% Mg) and concentrates (.04 or .24% Mg) fed separately for ad libitum consumption. Treatments were administered in a sequence, which involved each calf with all combinations of MgCl2·6H2O dosing routes and dietary Mg within a 6-wk period. Plasma Mg concentration averaged 1.95 mg/dl initially but fell below 1 mg/dl within 2 wk after supplemental Mg was omitted. Maximum increases in plasma Mg concentration following oral or rectal dosing were 16 or 47% when dietary Mg was adequate and 48 or 124% when Mg was deficient. Calves fed either diet responded maximally to rectal infusion within 10min, but plasma Mg of deficient calves increased throughout 160min after oral dosing. Plasma Mg of deficient calves responded quicker and reached higher concentrations after rectal infusion, but the response was sustained longer after oral administration.