PSXIV-13 Novel DI/LC-MS/MS-based urinary metabolite signatures for monitoring dairy cows for occurrence of retained placenta.

The objective of the study was to determine the value of metabolic indicators characterising the energy and acid-base metabolism of dairy cows for predicting the risk of retained placenta (RP). The connection between RP and different factors analysed, and the effect of RP on the development of puerperal metritis (PM) as well as on reproduction and milk production was studied. A total of 105 Holstein-Friesian cows were included and sampled between days -14–0 prepartum and then on days 4, 10–14, 28–35, 56–63 and 84–91 postpartum, for metabolic tests. From day 4, at times coinciding with the days of metabolic sampling, uterine involution and metritis were monitored by clinical examination, and from days 28–35 ovarian activity was monitored by ultrasonography. On days -14–0, the plasma non-esterified fatty acids (NEFA) concentration showed a positive Odds Ratio (OR) 102.1, P < 0.05; while urinary net acid-base excretion (NABE) exhibited a negative correlation (OR 0.99; P < 0.05) with the odds of RP. NEFA and NABE were negatively correlated (Pearson’s coefficient: -0.24; P < 0.05). Ketonuria of grade ≥ 2+ increased the probability of RP (OR: Infinite; P < 0.05). On day -14–0 prepartum, elevated plasma NEFA concentration, decreasing urinary NABE and grade ≥ 2+ ketonuria indicates a higher risk of RP. The odds of RP were not influenced by parity, sex and viability of the calf, and the calving assistance. RP increased the risk of PM (OR: 27.3; P < 0.0001). The RP alone did not exert an influence on the metabolic status, reproductive performance or milk production of cows.

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A Targeted Serum Metabolomics GC–MS Approach Identifies Predictive Blood Biomarkers for Retained Placenta in Holstein Dairy Cows

Metabolites ◽

10.3390/metabo11090633 ◽

2021 ◽

Vol 11 (9) ◽

pp. 633

Author(s):

Guanshi Zhang ◽

Dawid Tobolski ◽

Grzegorz Zwierzchowski ◽

Rupasri Mandal ◽

David S. Wishart ◽

...

Keyword(s):

Dairy Cows ◽

Predictive Biomarkers ◽

Significant Drop ◽

Retained Placenta ◽

Disease Occurrence ◽

Polar Metabolites ◽

Time Periods ◽

Gas Chromatography Mass Spectroscopy ◽

Serum Metabolomics ◽

Increased Susceptibility

The retained placenta is a common pathology of dairy cows. It is associated with a significant drop in the dry matter intake, milk yield, and increased susceptibility of dairy cows to metritis, mastitis, and displaced abomasum. The objective of this study was to identify metabolic alterations that precede and are associated with the disease occurrence. Blood samples were collected from 100 dairy cows at −8 and −4 weeks prior to parturition and on the day of retained placenta, and only 16 healthy cows and 6 cows affected by retained placenta were selected to measure serum polar metabolites by a targeted gas chromatography–mass spectroscopy (GC-MS) metabolomics approach. A total of 27 metabolites were identified and quantified in the serum. There were 10, 18, and 17 metabolites identified as being significantly altered during the three time periods studied. However, only nine metabolites were identified as being shared among the three time periods including five amino acids (Asp, Glu, Ser, Thr, and Tyr), one sugar (myo-inositol), phosphoric acid, and urea. The identified metabolites can be used as predictive biomarkers for the risk of retained placenta in dairy cows and might help explain the metabolic processes that occur prior to the incidence of the disease and throw light on the pathomechanisms of the disease.

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