title: Milk fatty acids as possible biomarkers to diagnose hyperketonemia in early lactation.
abstract: The aim of this study was to assess the potential of milk fatty acids as diagnostic tool for hyperketonemia of 93 dairy cows in a 3×2 factorial arrangement. Cows were fed a glucogenic or lipogenic diet and originally were intended to be subjected to a 0-, 30-, or 60-d dry period. Nevertheless, some of the cows, which were intended for inclusion in the 0-d dry period group, dried off spontaneously. Milk was collected in wk 2, 3, 4, and 8 of lactation for milk fat analysis. Blood was sampled from wk 2 to 8 after parturition for β-hydroxybutyrate (BHBA) analysis. Cases were classified into 2 groups: hyperketonemia (BHBA ≥1.2mmol/L) and nonhyperketonemia (BHBA <1.2mmol/L). Concentrations of 45 milk fatty acids and ratios of anteiso C15:0-to-anteiso C17:0 and C18:1 cis-9-to-C15:0 were subjected to a logistic regression analysis (stepwise forward method). The milk fat C18:1 cis-9-to-C15:0 ratio revealed the most discriminating factor for diagnosis of hyperketonemia. Ninety percent of nonhyperketonemia cases showed a milk fat C18:1 cis-9-to-C15:0 ratio of 40 or lower, whereas 70% of cows suffering from hyperketonemia showed milk fat C18:1 cis-9-to-C15:0 ratios exceeding 40. Additionally, cows with a milk fat ratio C18:1 cis-9-to-C15:0 of at least 45 in wk 2 after parturition had about 50% chance to encounter blood plasma BHBA values of 1.2mmol/L or more during the first 8 wk of lactation. Of the cows not suffering from hyperketonemia during the first 2 mo of lactation, only 9% exceeded this wk 2 threshold. Practical implementation requires routine analysis of both milk fatty acids, which currently is lacking for C15:0. The inclusion of other variables, such as test-day information and a more frequent sampling protocol should be considered to further improve diagnostic performance of this biomarker.
authors.affiliation: Laboratory for Animal Nutrition and Animal Product Quality, Ghent University, Proefhoevestraat 10, 9090 Melle, Belgium.
authors.forename: S
authors.initials: S
authors.lastname: Jorjong
authors.affiliation: Adaptation Physiology Group, Department of Animal Science, Wageningen University, PO Box 338, 6700 AH Wageningen, the Netherlands.
authors.forename: A T M
authors.initials: AT
authors.lastname: van Knegsel
authors.affiliation: KERMIT, Department of Mathematical Modelling, Statistics and Bioinformatics, Ghent University, Coupure links 653, 9000 Ghent, Belgium.
authors.forename: J
authors.initials: J
authors.lastname: Verwaeren
authors.affiliation: Veterinary Physiology, Vetsuisse Faculty, University of Bern, Bremgartenstrasse 109ª, CH-3001 Bern, Switzerland.
authors.forename: R M
authors.initials: RM
authors.lastname: Bruckmaier
authors.affiliation: KERMIT, Department of Mathematical Modelling, Statistics and Bioinformatics, Ghent University, Coupure links 653, 9000 Ghent, Belgium.
authors.forename: B
authors.initials: B
authors.lastname: De Baets
authors.affiliation: Adaptation Physiology Group, Department of Animal Science, Wageningen University, PO Box 338, 6700 AH Wageningen, the Netherlands.
authors.forename: B
authors.initials: B
authors.lastname: Kemp
authors.affiliation: Laboratory for Animal Nutrition and Animal Product Quality, Ghent University, Proefhoevestraat 10, 9090 Melle, Belgium. Electronic address: veerle.fievez@ugent.be.
authors.forename: V
authors.initials: V
authors.lastname: Fievez
mesh_terms: D020155:3-Hydroxybutyric Acid / Q000097:blood*; D000821:Animal Feed / Q000032:analysis; D000818:Animals; D015415:Biomarkers / Q000097:blood; D002417:Cattle; D002418:Cattle Diseases / Q000175:diagnosis* / Q000209:etiology; D004032:Diet / Q000662:veterinary; D005227:Fatty Acids / Q000097:blood*; D005260:Female; D007662:Ketosis / Q000175:diagnosis / Q000209:etiology / Q000662:veterinary*; D007774:Lactation; D008892:Milk / Q000737:chemistry
chemical_list: D015415:Biomarkers; D005227:Fatty Acids; D020155:3-Hydroxybutyric Acid
keywords: biomarker; hyperketonemia; milk fatty acid