title: Heritability of metabolic response to the intravenous glucose tolerance test in German Holstein Friesian bulls.
abstract: Selection for improved health and welfare in farm animals is of increasing interest worldwide. Peripartum energy balance is a key factor for pathogenesis of diseases in dairy cows. The intravenous glucose tolerance test (ivGTT) can be used to study the metabolic response to a glucose stimulus. The aim of this study was to estimate heritability of ivGTT traits in German Holstein bulls. A total of 541 Holstein bulls aged 7 to 17 mo from 2 breeding stations were subjected to the ivGTT. Serum glucose concentrations were measured at 0, 7, 14, 21, 28, 35, 42, 49, 56, and 63 min relative to glucose infusion. The maximum increase in blood glucose concentration, glucose area equivalent, and blood glucose half-life period were calculated. Heritabilities were estimated using a univariate animal model including station-year-season and age as fixed effects, and animal additive genetic and residual as random effects. The estimated heritabilities were 0.19 for fasting glucose concentration, 0.43 for glucose area equivalent, 0.40 for glucose half-life period, 0.14 for the peak glucose concentration, and 0.12 for the maximum increase of blood glucose concentration. Correlations between ivGTT traits and breeding values for milk yield and composition were not found. The results indicate that heritability for response to glucose is high, which warrants further investigation of this trait for genetic improvement of metabolic disorders. Research is necessary to determine the target levels of ivGTT traits and potential associations between ivGTT traits in breeding bulls and periparturient diseases in their offspring.
authors.affiliation: Ruminant and Swine Clinic, Biostatistics, Free University of Berlin, 14163 Berlin, Germany; Institute for Veterinary Epidemiology and Biostatistics, Free University of Berlin, 14163 Berlin, Germany. Electronic address: laura.pieper@fu-berlin.de.
authors.forename: Laura
authors.initials: L
authors.lastname: Pieper
authors.affiliation: Ruminant and Swine Clinic, Biostatistics, Free University of Berlin, 14163 Berlin, Germany.
authors.forename: Rudolf
authors.initials: R
authors.lastname: Staufenbiel
authors.affiliation: Ruminant and Swine Clinic, Biostatistics, Free University of Berlin, 14163 Berlin, Germany.
authors.forename: Jana
authors.initials: J
authors.lastname: Christ
authors.affiliation: Leibniz Institute for Farm Animal Biology (FBN), 18196 Dummerstorf, Germany.
authors.forename: Lothar
authors.initials: L
authors.lastname: Panicke
authors.affiliation: Albrecht Daniel Thaer-Institute for Agricultural and Horticultural Sciences, Animal Breeding Biology and Molecular Genetics, Humboldt University of Berlin, 10115 Berlin, Germany.
authors.forename: Uwe
authors.initials: U
authors.lastname: Müller
authors.affiliation: Albrecht Daniel Thaer-Institute for Agricultural and Horticultural Sciences, Animal Breeding Biology and Molecular Genetics, Humboldt University of Berlin, 10115 Berlin, Germany.
authors.forename: Gudrun A
authors.initials: GA
authors.lastname: Brockmann
mesh_terms: D000818:Animals; D001786:Blood Glucose / Q000378:metabolism*; D001947:Breeding; D002417:Cattle / Q000235:genetics*; D004734:Energy Metabolism / Q000235:genetics*; D005260:Female; D005951:Glucose Tolerance Test; D007328:Insulin / Q000097:blood; D007774:Lactation; D008297:Male; D008892:Milk / Q000378:metabolism; D058725:Peripartum Period / Q000097:blood / Q000235:genetics; D010641:Phenotype; D019655:Quantitative Trait, Heritable
chemical_list: D001786:Blood Glucose; D007328:Insulin
keywords: breeding bull; glucose; glucose tolerance test; heritability; metabolism