title: Genetic parameters for milk mineral content and acidity predicted by mid-infrared spectroscopy in Holstein-Friesian cows.
abstract: The aim of the present study was to estimate genetic parameters for calcium (Ca), phosphorus (P) and titratable acidity (TA) in bovine milk predicted by mid-IR spectroscopy (MIRS). Data consisted of 2458 Italian Holstein-Friesian cows sampled once in 220 farms. Information per sample on protein and fat percentage, pH and somatic cell count, as well as test-day milk yield, was also available. (Co)variance components were estimated using univariate and bivariate animal linear mixed models. Fixed effects considered in the analyses were herd of sampling, parity, lactation stage and a two-way interaction between parity and lactation stage; an additive genetic and residual term were included in the models as random effects. Estimates of heritability for Ca, P and TA were 0.10, 0.12 and 0.26, respectively. Positive moderate to strong phenotypic correlations (0.33 to 0.82) existed between Ca, P and TA, whereas phenotypic weak to moderate correlations (0.00 to 0.45) existed between these traits with both milk quality and yield. Moderate to strong genetic correlations (0.28 to 0.92) existed between Ca, P and TA, and between these predicted traits with both fat and protein percentage (0.35 to 0.91). The existence of heritable genetic variation for Ca, P and TA, coupled with the potential to predict these components for routine cow milk testing, imply that genetic gain in these traits is indeed possible.
authors.affiliation: 1Department of Agronomy,Food,Natural resources,Animals and Environment (DAFNAE),University of Padova,Viale dell'Università 16,35020 Legnaro,PD,Italy.
authors.forename: V
authors.initials: V
authors.lastname: Toffanin
authors.affiliation: 1Department of Agronomy,Food,Natural resources,Animals and Environment (DAFNAE),University of Padova,Viale dell'Università 16,35020 Legnaro,PD,Italy.
authors.forename: M
authors.initials: M
authors.lastname: Penasa
authors.affiliation: 2Livestock Systems Research Department,Animal and Grassland Research and Innovation Centre,Teagasc,Moorepark,Fermoy,Co. Cork,Ireland.
authors.forename: S
authors.initials: S
authors.lastname: McParland
authors.affiliation: 3Animal and Bioscience Research Department,Animal and Grassland Research and Innovation Centre,Teagasc,Moorepark,Fermoy,Co. Cork,Ireland.
authors.forename: D P
authors.initials: DP
authors.lastname: Berry
authors.affiliation: 1Department of Agronomy,Food,Natural resources,Animals and Environment (DAFNAE),University of Padova,Viale dell'Università 16,35020 Legnaro,PD,Italy.
authors.forename: M
authors.initials: M
authors.lastname: Cassandro
authors.affiliation: 1Department of Agronomy,Food,Natural resources,Animals and Environment (DAFNAE),University of Padova,Viale dell'Università 16,35020 Legnaro,PD,Italy.
authors.forename: M
authors.initials: M
authors.lastname: De Marchi
mesh_terms: D000818:Animals; D002417:Cattle / Q000235:genetics* / Q000502:physiology; D002452:Cell Count; D005260:Female; D014644:Genetic Variation; D006863:Hydrogen-Ion Concentration; D007774:Lactation / Q000235:genetics; D016014:Linear Models; D008892:Milk / Q000737:chemistry* / Q000166:cytology; D008903:Minerals / Q000737:chemistry*; D010641:Phenotype; D011247:Pregnancy; D013055:Spectrophotometry, Infrared / Q000662:veterinary*
chemical_list: D008903:Minerals
keywords: genetic parameter