title: [Activity of the alkaline phosphatase in the serum and bones of zinc-deficient and zinc-replenished cows].
abstract: In a study with five lactating dairy cows fed a semisynthetic diet, the changes in the activity of the alkaline phosphatase in the serum, bones and milk were investigated in response to dietary depletion and repletion of zinc. During a six-week depletion period (6 mg Zn/kg dry matter) the alkaline phosphatase in the serum decreased to only 82% of its initial level which, however, was reduced already due to a low zinc intake before the start of the study. After 19 weeks of depletion the activity had decreased to 43% of its initial level. Additions of zinc during the repletion increased the activity very clearly and to much higher values than the ones at the start of the study. Thus this effect of repletion was as large as that for the zinc content in serum and milk. The serum alkaline phosphatase indicated a dependence on the performance and represents a sensitive indicator of the zinc status. The activity of the alkaline phosphatase in the bones (Tuber coxae) decreased to 68% of its initial level after six weeks of zinc depletion. The alkaline phosphatase in the milk was not influenced by the zinc supply.
mesh_terms: D000469:Alkaline Phosphatase / Q000097:blood / Q000378:metabolism*; D000818:Animals; D001842:Bone and Bones / Q000201:enzymology; D002417:Cattle; D003677:Deficiency Diseases / Q000201:enzymology / Q000662:veterinary*; D008892:Milk / Q000032:analysis; D015032:Zinc / Q000008:administration & dosage / Q000032:analysis / Q000172:deficiency*
chemical_list: D000469:Alkaline Phosphatase; D015032:Zinc
vernacular_title: Zur Aktivität der alkalischen Phosphatase in Serum und Knochen von zinkdepleteirten und -repletierten Kühen. 16. Mittellung Zum Stoffwechsel des Zinks im tierischen Organismus