title: Transient lowering of plasma vitamin B12 concentrations in Ouessant sheep fed on a potassium-rich ration.
abstract: The hypothesis tested was that a high intake of potassium (K) interferes with cobalt (Co)-vitamin B12 metabolism in ruminants. Ouessant sheep were fed either a low- (8 g K/kg dry matter) or high-K diet (43 g K/kg dry matter) with an adequate amount of Co (124 micrograms Co/kg dry matter). Plasma vitamin B12 concentrations were measured. Sheep fed a low-K diet, but containing only 70 micrograms Co/kg dry matter, served as positive controls. Feeding the low-Co ration produced a significant decrease in plasma vitamin B12 concentrations. The high- versus low-K ration induced a significant decrease in plasma vitamin B12 during the first 6 weeks, but thereafter the values in the high-K group rose to those seen in the low-K group. The mechanism by which dietary K may interact with Co-vitamin B12 metabolism in sheep is unknown.
authors.affiliation: Department of Nutrition, Faculty of Veterinary Medicine, Utrecht University, The Netherlands.
authors.forename: J J
authors.initials: JJ
authors.lastname: Smit
authors.forename: J T
authors.initials: JT
authors.lastname: Schonewille
authors.forename: A C
authors.initials: AC
authors.lastname: Beynen
mesh_terms: D000821:Animal Feed; D000818:Animals; D001835:Body Weight; D002149:Energy Intake; D008297:Male; D017419:Potassium, Dietary / Q000494:pharmacology*; D012756:Sheep / Q000097:blood*; D014805:Vitamin B 12 / Q000097:blood*
chemical_list: D017419:Potassium, Dietary; D014805:Vitamin B 12