title: 1 alpha-hydroxyvitamin D3 plus 25-hydroxyvitamin D3 reduces parturient paresis in dairy cows fed high dietary calcium.
abstract: The effectiveness of a combination of 1 alpha-hydroxyvitamin D3 and 25-hydroxyvitamin D3 for reducing incidence of parturient paresis in aged Holstein cows was tested. Intramuscular injection of .5 mg of 1 alpha-hydroxyvitamin D3 plus 4 mg of 25-hydroxyvitamin D3 increased plasma 1,25-dihydroxyvitamin D concentrations through parturition. Treatment with 1 alpha-hydroxyvitamin D3 plus 25-hydroxyvitamin D3 raised prepartum serum Ca approximately 2 mg/dl and prepartum serum P approximately 4 to 5 mg/dl higher than untreated controls. Both treated and control cows had approximately a 2-mg/dl decrease in serum Ca following parturition. The prepartum diet of alfalfa silage and hay was supplemented with a grain mixture supplying 100 g of Ca/d from ground limestone. Under these dietary conditions, incidence of parturient paresis was reduced from 33 to 8%. In a separate experiment, treatment with 1 alpha-hydroxyvitamin D3 plus 25-hydroxyvitamin D3 did not reduce incidence of parturient paresis when cows consumed mixed diets of different feed-stuff composition. Further experiments are required to determine specifically the factor or factors responsible for the difference in response to active vitamin D compound administration between the two experiments. Prepartum dietary Ca intake may be one such factor.
authors.affiliation: College of Agricultural and Life Sciences, University of Wisconsin, Madison 53706.
authors.forename: D W
authors.initials: DW
authors.lastname: Hodnett
authors.forename: N A
authors.initials: NA
authors.lastname: Jorgensen
authors.forename: H F
authors.initials: HF
authors.lastname: Deluca
mesh_terms: D000818:Animals; D002112:Calcifediol / Q000008:administration & dosage / Q000627:therapeutic use*; D002117:Calcitriol / Q000097:blood; D002118:Calcium / Q000008:administration & dosage / Q000097:blood; D002136:Calcium, Dietary / Q000008:administration & dosage* / Q000493:pharmacokinetics; D002417:Cattle; D002418:Cattle Diseases / Q000517:prevention & control*; D004338:Drug Combinations; D005260:Female; D006887:Hydroxycholecalciferols / Q000008:administration & dosage / Q000627:therapeutic use*; D007273:Injections, Intramuscular / Q000662:veterinary; D007408:Intestinal Absorption / Q000187:drug effects; D007743:Labor, Obstetric / Q000097:blood; D010319:Parturient Paresis / Q000517:prevention & control*; D010758:Phosphorus / Q000097:blood; D011247:Pregnancy
chemical_list: D002136:Calcium, Dietary; D004338:Drug Combinations; D006887:Hydroxycholecalciferols; D010758:Phosphorus; D002117:Calcitriol; D002112:Calcifediol; D002118:Calcium; C008088:alfacalcidol