title: Lactation-induced changes in metabolic status and follicular-fluid metabolomic profile in postpartum dairy cows.
abstract: The aim was to investigate the effect of lactation on the composition of pre-ovulatory follicular fluid (FF). Forty in-calf primiparous heifers and 20 maiden heifers were enrolled. Immediately after calving, half of the cows were dried off while the remainder were milked twice daily. Serum samples were collected twice weekly from two weeks pre- to 84 days postpartum (dpp). FF was analysed by gas chromatography-mass spectrometry. Serum concentrations of non-esterified fatty acids and β-hydroxybutyrate were higher, while glucose, insulin and Insulin-like growth factor 1 (IGF1) concentrations were lower in lactating cows compared with non-lactating cows and heifers (P<0.01). Principal component analysis of FF metabolites revealed a clear separation of the lactating group from both non-lactating cows and heifers. The amino acids tyrosine, phenylalanine and valine and fatty acids heneicosanoic acid and docosahexaenoic acid were all lower in FF from lactating compared with dry cows (P<0.05). FF from lactating cows was higher in aminoadipic acid, α-aminobutyric acid, glycine and serine while histidine, leucine, lysine, methionine and ornithine were all lower than in dry cows and heifers (P<0.05). The ratio of n6:n3 was higher in lactating cows compared with both non-lactating cows and heifers, whereas total n3 polyunsaturated fatty acids, pentadecanoic, linolenic, elaidic and arachidonic acids were all lower in the FF of lactating cows than both non-lactating cows and heifers (P<0.05). In conclusion, lactation induces distinct changes in the overall metabolic status of postpartum lactating dairy cows which are associated with divergent metabolite profiles in FF.
authors.affiliation: School of Agriculture and Food Science, University College Dublin, Belfield, Dublin 4, Ireland.
authors.forename: Niamh
authors.initials: N
authors.lastname: Forde
authors.affiliation: School of Agriculture and Food Science, University College Dublin, Belfield, Dublin 4, Ireland.
authors.forename: Aoife
authors.initials: A
authors.lastname: O'Gorman
authors.affiliation: School of Agriculture and Food Science, University College Dublin, Belfield, Dublin 4, Ireland.
authors.forename: Helena
authors.initials: H
authors.lastname: Whelan
authors.affiliation: School of Agriculture and Food Science, University College Dublin, Belfield, Dublin 4, Ireland.
authors.forename: Pat
authors.initials: P
authors.lastname: Duffy
authors.affiliation: School of Agriculture and Food Science, University College Dublin, Belfield, Dublin 4, Ireland.
authors.forename: Lydia
authors.initials: L
authors.lastname: O'Hara
authors.affiliation: School of Agriculture and Food Science, University College Dublin, Belfield, Dublin 4, Ireland.
authors.forename: Alan K
authors.initials: AK
authors.lastname: Kelly
authors.affiliation: Reproduction Centre - Wieselburg, University of Veterinary Medicine Vienna, Veterinärplatz 1, A-1210, Austria.
authors.forename: Vitezslav
authors.initials: V
authors.lastname: Havlicek
authors.affiliation: Reproduction Centre - Wieselburg, University of Veterinary Medicine Vienna, Veterinärplatz 1, A-1210, Austria.
authors.forename: Urban
authors.initials: U
authors.lastname: Besenfelder
authors.affiliation: School of Agriculture and Food Science, University College Dublin, Belfield, Dublin 4, Ireland.
authors.forename: Lorraine
authors.initials: L
authors.lastname: Brennan
authors.affiliation: School of Agriculture and Food Science, University College Dublin, Belfield, Dublin 4, Ireland.
authors.forename: Pat
authors.initials: P
authors.lastname: Lonergan
mesh_terms: D000818:Animals; D002417:Cattle / Q000502:physiology*; D005230:Fatty Acids, Nonesterified / Q000097:blood; D005260:Female; D015571:Follicular Fluid / Q000378:metabolism*; D007774:Lactation; D055442:Metabolome; D049590:Postpartum Period
chemical_list: D005230:Fatty Acids, Nonesterified