title: Effects of dietary Cu, Mo and S on urinary Cu and Zn excretion in Simmental and Angus cattle.
abstract: This study determined the effects of dietary copper (Cu), molybdenum (Mo) and sulphur (S) on urinary Cu and zinc (Zn) excretion in cattle. Four Simmental and four Angus heifers were fed low (L) or high (H) levels (mg/kg DM) of Cu (5,40), Mo (1,10) and S (0.2,0.5%). Initially two of each breed was fed either LCu or HCu (2 mo). Then all eight animals were fed sequentially LCuHS (1.5 mo), HCuHS, HCuHMo and HCuHMoHS (2 mo each). Simmental had a higher urine flow, increased concentration and total excretion of urinary Cu and Zn compared to Angus, but only total Zn excretion was significantly higher. Urinary Cu excretion was greatest with the HCuHMoHS diet. Urinary Zn excretion significantly increased with HS but not HS in combination with HMo and/or HCu. This study, together with previously reported biliary excretion, allows a direct comparison of urinary and biliary Cu and Zn excretion responses to dietary Cu, Mo and S.
authors.affiliation: Faculty of Agriculture and Life Sciences, P.O. Box 84, Lincoln University, Lincoln 7647, New Zealand. Ravi.Gooneratne@lincoln.ac.nz
authors.forename: S R
authors.initials: SR
authors.lastname: Gooneratne
authors.forename: B
authors.initials: B
authors.lastname: Laarveld
authors.forename: K K
authors.initials: KK
authors.lastname: Pathirana
authors.forename: D A
authors.initials: DA
authors.lastname: Christensen
mesh_terms: D000821:Animal Feed / Q000032:analysis; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D002417:Cattle; D003300:Copper / Q000008:administration & dosage / Q000494:pharmacology* / Q000652:urine*; D004032:Diet / Q000662:veterinary; D004305:Dose-Response Relationship, Drug; D005260:Female; D014644:Genetic Variation; D008982:Molybdenum / Q000494:pharmacology*; D013455:Sulfur / Q000494:pharmacology*; D015032:Zinc / Q000652:urine*
chemical_list: D013455:Sulfur; D003300:Copper; D008982:Molybdenum; D015032:Zinc