title: The association between serum ß-hydroxybutyrate and milk fatty acid profile with special emphasis on conjugated linoleic acid in postpartum Holstein cows.
abstract: BACKGROUND
  Ketogenesis is a secondary metabolic pathway to provide energy to dairy cows during early lactation; however when the production of ketone bodies (acetoacetate, acetone, ß- hydroxybutyrate) is above certain levels a subclinical disorder may appear. The aim of the present study was to investigate the association between serum concentrations of ß- hydroxybutyrate (BHBA) and fatty acid (FA) profile of milk with emphasis in conjugated linoleic acid (CLA) in a population of early lactation Holstein cows. Fifty cows between parity 1 and 5, ranging from 14 to 21 days in milk, were randomly selected from 3 farms of the central area of Chile for determination of serum BHBA concentrations, milk fat content, and milk FA profiles.
  
  
  RESULTS
  Cows were divided in low (n = 26) and high (n = 24) BHBA groups considering the median value of the serum concentration of BHBA (0.7 mmol/L) (SEM = 0.094). Mean milk fat % was 3.45% and 3.60% for cows in the low and high BHBA groups, respectively (P = 0.15). Concentrations of several FA were significantly different between both groups. Specifically, mean CLA concentrations were 0.40% (4 ± 0.03 g/kg) and 0.33% (3.3 ± 0.03 g/kg) for the low and high BHBA groups, respectively (P = 0.05).
  
  
  CONCLUSIONS
  It is concluded that early postpartum cows with serum BHBA > 0.7 mmol/L tended to have higher milk fat % and had significantly lower concentrations of CLA than early postpartum cows with BHBA ≤ 0.7 mmol/L.
authors.affiliation: College of Veterinary Medicine, University of Missouri, Columbia, MO, 65211, USA.
authors.forename: Pedro
authors.initials: P
authors.lastname: Melendez
authors.affiliation: Texas A&M AgriLife Research & Extension Center, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University System, Amarillo, TX, 79106-1769, USA. pinedop@colostate.edu.|Present Address: Department of Animal Sciences, Colorado State University, Fort Collins, CO, 80523, USA. pinedop@colostate.edu.
authors.forename: Pablo
authors.initials: P
authors.lastname: Pinedo
authors.affiliation: College of Veterinary Medicine, University Santo Tomas, Viña del Mar, Chile.
authors.forename: José
authors.initials: J
authors.lastname: Bastias
authors.affiliation: College of Veterinary Medicine, University Santo Tomas, Viña del Mar, Chile.
authors.forename: Maria Paz
authors.initials: MP
authors.lastname: Marin
authors.affiliation: College of Veterinary Medicine, University Santo Tomas, Viña del Mar, Chile.
authors.forename: Carolina
authors.initials: C
authors.lastname: Rios
authors.affiliation: College of Veterinary Medicine, University Santo Tomas, Viña del Mar, Chile.
authors.forename: Consuelo
authors.initials: C
authors.lastname: Bustamante
authors.affiliation: College of Veterinary Medicine, University Santo Tomas, Viña del Mar, Chile.
authors.forename: Natalia
authors.initials: N
authors.lastname: Adaro
authors.affiliation: College of Veterinary Medicine, University of Chile, Santiago, Chile.
authors.forename: Mario
authors.initials: M
authors.lastname: Duchens
mesh_terms: D020155:3-Hydroxybutyric Acid / Q000097:blood*; D000818:Animals; D002417:Cattle; D002677:Chile; D003612:Dairying; D005227:Fatty Acids / Q000378:metabolism*; D005260:Female; D007774:Lactation / Q000097:blood; D044243:Linoleic Acids, Conjugated / Q000378:metabolism*; D008892:Milk / Q000378:metabolism*; D049590:Postpartum Period / Q000097:blood
chemical_list: D005227:Fatty Acids; D044243:Linoleic Acids, Conjugated; D020155:3-Hydroxybutyric Acid
keywords: Conjugated linoleic acid; Ketone bodies; ß- hydroxybutyrate