title: Metabolomic biomarkers correlating with hepatic lipidosis in dairy cows.
abstract: BACKGROUND
  Hepatic lipidosis or fatty liver disease is a major metabolic disorder of high-producing dairy cows that compromises animal performance and, hence, causes heavy economic losses worldwide. This syndrome, occurring during the critical transition from gestation to early lactation, leads to an impaired health status, decreased milk yield, reduced fertility and shortened lifetime. Because the prevailing clinical chemistry parameters indicate advanced liver damage independently of the underlying disease, currently, hepatic lipidosis can only be ascertained by liver biopsy. We hypothesized that the condition of fatty liver disease may be accompanied by an altered profile of endogenous metabolites in the blood of affected animals.
  
  
  RESULTS
  To identify potential small-molecule biomarkers as a novel diagnostic alternative, the serum samples of diseased dairy cows were subjected to a targeted metabolomics screen by triple quadrupole mass spectrometry. A subsequent multivariate test involving principal component and linear discriminant analyses yielded 29 metabolites (amino acids, phosphatidylcholines and sphingomyelines) that, in conjunction, were able to distinguish between dairy cows with no hepatic lipidosis and those displaying different stages of the disorder.
  
  
  CONCLUSIONS
  This proof-of-concept study indicates that metabolomic profiles, including both amino acids and lipids, distinguish hepatic lipidosis from other peripartal disorders and, hence, provide a promising new tool for the diagnosis of hepatic lipidosis. By generating insights into the molecular pathogenesis of hepatic lipidosis, metabolomics studies may also facilitate the prevention of this syndrome.
authors.forename: Sandro
authors.initials: S
authors.lastname: Imhasly
authors.affiliation: University of Zürich-Vetsuisse, Institute of Pharmacology and Toxicology, Zürich CH-8057, Switzerland. naegelih@vetpharm.uzh.ch.
authors.forename: Hanspeter
authors.initials: H
authors.lastname: Naegeli
authors.forename: Sven
authors.initials: S
authors.lastname: Baumann
authors.forename: Martin
authors.initials: M
authors.lastname: von Bergen
authors.forename: Andreas
authors.initials: A
authors.lastname: Luch
authors.forename: Harald
authors.initials: H
authors.lastname: Jungnickel
authors.forename: Sarah
authors.initials: S
authors.lastname: Potratz
authors.forename: Christian
authors.initials: C
authors.lastname: Gerspach
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000097:blood; D002417:Cattle; D002418:Cattle Diseases / Q000097:blood* / Q000378:metabolism; D003612:Dairying; D008064:Lipidoses / Q000662:veterinary*; D008107:Liver Diseases / Q000097:blood / Q000378:metabolism / Q000662:veterinary*
chemical_list: D015415:Biomarkers