title: Influence of breed on blood and tissue copper status in growing and finishing steers fed diets supplemented with copper.
abstract: To evaluate the influence of breed on the accumulation of dietary copper (Cu) in tissue, and on blood parameters indicative of Cu status, ten Galician Blond, nine Holstein-Friesian and ten Galician Blond x Holstein-Friesian cross (GB x HF) steers were fed diets supplemented with 35 mg/kg DM of CuSO4 during their growing and finishing periods. Blood samples were taken monthly, and samples of liver, kidney, brain, heart, spleen and muscle were taken at slaughter. Cu concentrations were determined by ICP-AES. Holstein-Friesian calves had significantly higher total liver Cu contents than Galician Blonds and GB x HF crosses (mean 1070, 663 and 868 mg, respectively), combined with higher hepatic Cu concentrations (174, 140 and 166 mg/kg wet weight, respectively). Holstein-Friesian calves had also the highest prevalence (89%) of hepatic Cu concentrations exceeding the toxic limit of 150 mg/kg wet weight. Breed did not have a statistically significant influence on blood parameters. With the exception of the semitendinosus muscle, where Holstein-Friesians (0.790 mg/kg) had significantly higher Cu levels than Galician Blonds (0.541 mg/kg) or GB x HF crosses (0.631 mg/kg), no other statistically significant differences by breed in the extrahepatic tissue Cu distribution were observed. A negative statistical association between carcass performance and the ratio of semitendinosus and liver Cu concentration could indicate that the animals with a better carcass performance (Galician Blonds) could need a higher Cu mobilisation into the muscle, resulting in a lower hepatic storage.
authors.affiliation: Department of Clinical Veterinary Science, Faculty of Veterinary, University of Santiago de Compostela, Lugo, Spain. marta.miranda@usc.es
authors.forename: Marta
authors.initials: M
authors.lastname: Miranda
authors.forename: Betiana
authors.initials: B
authors.lastname: Gutiérrez
authors.forename: José Luis
authors.initials: JL
authors.lastname: Benedito
authors.forename: Isabel
authors.initials: I
authors.lastname: Blanco-Penedo
authors.forename: Marco
authors.initials: M
authors.lastname: García-Vaquero
authors.forename: Marta
authors.initials: M
authors.lastname: López-Alonso
mesh_terms: D000821:Animal Feed / Q000032:analysis; D000824:Animal Nutritional Physiological Phenomena / Q000235:genetics*; D000818:Animals; D002417:Cattle / Q000097:blood* / Q000235:genetics*; D003300:Copper / Q000172:deficiency / Q000378:metabolism*; D004032:Diet / Q000662:veterinary; D019587:Dietary Supplements; D004305:Dose-Response Relationship, Drug; D007668:Kidney / Q000737:chemistry; D008099:Liver / Q000737:chemistry; D008297:Male; D018482:Muscle, Skeletal / Q000737:chemistry; D009206:Myocardium / Q000737:chemistry; D013154:Spleen / Q000737:chemistry; D013997:Time Factors
chemical_list: D003300:Copper