title: A pathologic and toxicologic evaluation of veal calves fed large amounts of zinc.
abstract: Tissues were examined from 26 male Holstein veal calves given large amounts of dietary zinc. All calves had been fed 706 micrograms zinc/g of milk replacer for 28 days before the first death occurred. Calves died naturally (14, group A) or were euthanatized (12, group B) after 23 days of feeding a lower concentration of zinc (150 micrograms/g). Average amounts of zinc in liver (wet weight) were 345.72 micrograms/g (group A) and 344.84 micrograms/g (group B). Mean kidney zinc concentrations were 219.0 micrograms/g (group A) and 252.38 micrograms/g (group B). Tissue manganese, copper, and iron levels were normal. Changes at necropsy included pneumonia, fluid digesta, and petechiae and infarcts in liver, kidney, and heart (as a result of bacterial infections). Histological changes that were directly attributed to dietary zinc intake were: marked atrophy and necrosis of pancreatic acinar tissue (group A); multifocal fibrosis of pancreatic acini (group B); multifocal renal cortical fibrosis with necrosis in convoluted tubules and loops of Henle, and with intratubular mineralization (groups A and B). Hepatic midzonal mineralization and fibrosis of the adrenal zona glomerulosa were seen in group B calves.
authors.affiliation: Department of Pathology, School of Veterinary Medicine, University of California-Davis, Tulare.
authors.forename: T W
authors.initials: TW
authors.lastname: Graham
authors.forename: C A
authors.initials: CA
authors.lastname: Holmberg
authors.forename: C L
authors.initials: CL
authors.lastname: Keen
authors.forename: M C
authors.initials: MC
authors.lastname: Thurmond
authors.forename: M S
authors.initials: MS
authors.lastname: Clegg
mesh_terms: D000821:Animal Feed; D000818:Animals; D001923:Brain Chemistry; D002417:Cattle; D002418:Cattle Diseases / Q000139:chemically induced* / Q000473:pathology; D007668:Kidney / Q000032:analysis / Q000473:pathology; D008099:Liver / Q000032:analysis / Q000473:pathology; D008168:Lung / Q000473:pathology; D008297:Male; D009132:Muscles / Q000032:analysis; D010179:Pancreas / Q000473:pathology; D015032:Zinc / Q000633:toxicity*
chemical_list: D015032:Zinc