title: Alterations in milk metabolome and coagulation ability during the lactation of dairy cows.
abstract: Milk composition has been known to change during lactation. To help understand the changes in metabolic profile throughout the whole lactation, liquid chromatography mass-spectrometry was used to analyze 306 milk samples from 82 primi- and multiparous dairy cows. Changes in metabolic profile common to all cows throughout lactation were ascertained based on principal component and general linear model analysis. Sets of specific markers; for instance, 225, 397, and 641-642 m/z (positive mode), and 186, 241, and 601-604 (negative mode), with at least a 1.5-fold higher intensity during the first 60 d compared with the last 60 d of lactation were observed. The metabolome was affected by parity and milking time. Markers, identified as peptides differentiating parity, were observed. A significant increase for citrate was observed in evening milk. Milk coagulation traits were strongly animal specific. The curd firmness values were influenced by milking time. Sets of markers were associated with curd firmness in positive (197 m/z) and negative (612, 737, 835, 836, 902, 1000, 1038, and 1079 m/z) ion mode.
authors: Institute of Veterinary Medicine and Animal Science, Estonian University of Life Sciences, Kreutzwaldi 1, Tartu 51014, Estonia; Bio-Competence Centre of Healthy Dairy Products, Kreutzwaldi 1, 51014 Tartu, Estonia; Department of Biochemistry, Medical Faculty, University of Tartu, the Centre of Excellence for Translational Medicine, 50411 Tartu, Estonia. Electronic address: hedi.harzia@emu.ee.
authors: H
authors: H
authors: Harzia
authors: A
authors: A
authors: Ilves
authors: M
authors: M
authors: Ots
authors: M
authors: M
authors: Henno
authors: I
authors: I
authors: Jõudu
authors: T
authors: T
authors: Kaart
authors: K
authors: K
authors: Ling
authors: O
authors: O
authors: Kärt
authors: K
authors: K
authors: Kilk
authors: U
authors: U
authors: Soomets
mesh_terms: D000818:Animals; D002417:Cattle; D005260:Female; D007774:Lactation; D055442:Metabolome; D008892:Milk / Q000737:chemistry / Q000378:metabolism*
keywords: coagulation; lactation curve; milk metabolite