GC-MS Metabolomics Identifies Metabolite Alterations That Precede Subclinical Mastitis in the Blood of Transition Dairy Cows.
The objectives of this study were to determine alterations in the serum metabolites related to amino acid (AA), carbohydrate, and lipid metabolism in transition dairy cows before diagnosis of subclinical mastitis (SCM), during, and after diagnosis of disease. A subclinical mastitis case was determined as a cow having somatic cell count (SCC) > 200 000/mL of milk for two or more consecutive reports. Blood samples were collected from 100 Holstein dairy cows at five time points at -8 and -4 weeks before parturition, at the week of SCM diagnosis, and +4 and +8 weeks after parturition. Twenty healthy control cows (CON) and six cows that were diagnosed with SCM were selected for serum analysis with GC-MS. At -8 weeks a total of 13 metabolites were significantly altered in SCM cows. In addition, at the week of SCM diagnosis 17 metabolites were altered in these cows. Four weeks after parturition 10 metabolites were altered in SCM cows and at +8 weeks 11 metabolites were found to be different between the two groups. Valine (Val), serine (Ser), tyrosine (Tyr), and phenylalanine (Phe) had very good predictive abilities for SCM and could be used at -8 weeks and -4 weeks before calving. Combination of Val, isoleucine (Ile), Ser, and proline (Pro) can be used as diagnostic biomarkers of SCM during early stages of lactation at +4 to +8 weeks after parturition. In conclusion, SCM is preceded and followed by alteration in AA metabolism.
Department of Agricultural, Food and Nutritional Science, University of Alberta , Edmonton, Alberta T6G 2P5, Canada.
Elda
E
Dervishi
Department of Agricultural, Food and Nutritional Science, University of Alberta , Edmonton, Alberta T6G 2P5, Canada.
Guanshi
G
Zhang
Department of Agricultural, Food and Nutritional Science, University of Alberta , Edmonton, Alberta T6G 2P5, Canada.
Suzanna M
SM
Dunn
Departments of Biological Sciences and Computing Science, University of Alberta , Edmonton, Alberta T6G 2E9, Canada.
Rupasri
R
Mandal
Departments of Biological Sciences and Computing Science, University of Alberta , Edmonton, Alberta T6G 2E9, Canada.
David S
DS
Wishart
Department of Agricultural, Food and Nutritional Science, University of Alberta , Edmonton, Alberta T6G 2P5, Canada.
Burim N
BN
Ametaj
D000821:Animal Feed / Q000032:analysis; D000818:Animals; D015415:Biomarkers / Q000097:blood; D002417:Cattle; D002452:Cell Count; D003612:Dairying; D042241:Early Diagnosis; D005260:Female; D008401:Gas Chromatography-Mass Spectrometry; D007774:Lactation / Q000502:physiology; D008414:Mastitis, Bovine / Q000097:blood / Q000175:diagnosis*; D055432:Metabolomics / Q000379:methods; D008892:Milk / Q000166:cytology; D036801:Parturition / Q000502:physiology; D010649:Phenylalanine / Q000097:blood*; D025341:Principal Component Analysis; D011379:Prognosis; D012694:Serine / Q000097:blood*; D014443:Tyrosine / Q000097:blood*; D014633:Valine / Q000097:blood*
D015415:Biomarkers; D014443:Tyrosine; D012694:Serine; D010649:Phenylalanine; D014633:Valine
GC−MS; amino acids; carbohydrates; dairy cow; metabolomics; subclinical mastitis