title: Effect of feeding 25-hydroxyvitamin D3 with a negative cation-anion difference diet on calcium and vitamin D status of periparturient cows and their calves.
abstract: Holstein cows (>1 gestation) were fed 1 of 3 diets during the last 13 d of gestation (ranged from 22 to 7 d). The control diet (16 cows) was formulated to provide 18,000 IU/d of vitamin D3 and had a dietary cation-anion difference (DCAD) of 165mEq/kg (DCAD=Na + K - Cl - S). The second diet (DCAD + D) provided the same amount of vitamin D3 but had a DCAD of -139mEq/kg (17 cows). The third diet (DCAD + 25D) had no supplemental vitamin D3 but provided 6mg/d of 25-(OH) vitamin D3 [25-(OH)D3] with a DCAD of -138mEq/kg (20 cows). Diets were fed until parturition and then all cows were fed a common lactation diet that contained vitamin D3. Negative DCAD diets reduced urine pH, with the greatest decrease occurring with the DCAD + D treatment. Urinary Ca excretion was greatest for cows fed DCAD + 25D followed by cows fed DCAD + D. Urinary pH was negatively correlated with urinary excretion of Ca for cows fed DCAD + D. No such correlation was observed with the DCAD + 25D treatment because substantial excretion of urinary Ca occurred at moderate urinary pH values for that treatment. Cows fed DCAD + 25D had greater serum concentrations of 25-(OH)D3 than other treatments from 5 d after supplementation started through 7 d in milk. Concentrations of 1,25-(OH)2D3 in serum were greatest in DCAD + 25D cows starting at 2 d before calving and continued through 7 d in milk. Serum Ca concentrations 5 d before calving were greatest for cows fed DCAD + 25D, but at other time points before and after parturition treatment did not affect serum Ca. Incidence of clinical hypocalcemia was not statistically different between treatments, but cows fed DCAD + 25 had the highest incidence rate (12.5, 0, and 20% for control, DCAD + D, and DCAD + 25D). Calves born from cows fed DCAD + 25D had greater concentrations of 25-(OH)D3 in serum at birth than calves from other treatments (before colostrum consumption), but concentrations were similar by 3 d of age. Concentrations of 25-(OH)D3 in colostrum and transition milk were increased by feeding DCAD + 25D, but by 28 d in milk treatment effects no longer existed. Overall, feeding 25-OH vitamin D with a negative DCAD diet increased vitamin D status of the cow and her newborn calf but had minimal effects on calcium status and did not have positive effects on the incidence of hypocalcemia.
authors.affiliation: Department of Animal Sciences, Ohio Agricultural Research and Development Center, The Ohio State University, Wooster 44691. Electronic address: Weiss.6@osu.edu.
authors.forename: W P
authors.initials: WP
authors.lastname: Weiss
authors.affiliation: DSM Nutritional Products Ltd., 4002 Basel, Switzerland.
authors.forename: E
authors.initials: E
authors.lastname: Azem
authors.affiliation: DSM Nutritional Products Ltd., 4002 Basel, Switzerland.
authors.forename: W
authors.initials: W
authors.lastname: Steinberg
authors.affiliation: Ruminant Diseases and Immunology Research Unit, National Animal Disease Center, USDA Agricultural Research Service, Ames, IA 50010.
authors.forename: T A
authors.initials: TA
authors.lastname: Reinhardt
mesh_terms: D000818:Animals; D000831:Animals, Newborn / Q000097:blood*; D000838:Anions / Q000008:administration & dosage; D002112:Calcifediol / Q000008:administration & dosage* / Q000032:analysis; D002118:Calcium / Q000097:blood* / Q000652:urine; D002136:Calcium, Dietary; D002412:Cations / Q000008:administration & dosage; D002417:Cattle / Q000097:blood*; D002418:Cattle Diseases / Q000097:blood; D003126:Colostrum / Q000737:chemistry; D004032:Diet / Q000662:veterinary*; D019587:Dietary Supplements; D005260:Female; D005865:Gestational Age; D006863:Hydrogen-Ion Concentration; D006996:Hypocalcemia / Q000097:blood / Q000662:veterinary; D007774:Lactation; D008892:Milk / Q000737:chemistry; D009752:Nutritional Status; D036801:Parturition; D014556:Urine / Q000737:chemistry; D014807:Vitamin D / Q000097:blood*
chemical_list: D000838:Anions; D002136:Calcium, Dietary; D002412:Cations; D014807:Vitamin D; D002112:Calcifediol; D002118:Calcium
keywords: dietary cation-anion difference; hypocalcemia; vitamin D