Integrated Metabolomics Study of the Milk of Heat-stressed Lactating Dairy Cows

Abstract

Heat stress (HS) damages the global dairy industry by reducing milk yields and quality, harming health, and damaging the reproduction of dairy cows, causing huge economic losses each year. However, an understanding of the physiological mechanism of HS lactating dairy cows remains elusive. Here, a metabolomics study using LC-MS and 1H NMR spectroscopy was performed to analyze the metabolomic differences in the milk between HS-free and HS dairy cows, and discover diagnostic biomarkers and changes in the metabolic pathway. A total of 53 discriminating metabolites were significantly up- or down-regulated in the HS group compared with the HS-free group (P < 0.05). These biomarkers were involved in pathways of carbohydrate, amino acid, lipid, and gut microbiome-derived metabolism. Comparing these potential biomarkers with previously identified HS candidate biomarkers in plasma, significant correlations between the levels of lactate, pyruvate, creatine, acetone, β-hydroxybutyrate, trimethylamine, oleic acid, linoleic acid, lysophosphatidylcholine 16:0, and phosphatidylcholine 42:2 in milk and plasma were found, indicating that the blood-milk barrier became leaky and the levels of these 10 biomarkers in milk can reflect HS-induced metabolomic alterations in blood. These novel findings can support more in-depth research to elucidate the milk-based changes in metabolic pathways in HS lactating dairy cows.

Characterization of chiral amino acids from different milk origins using ultra-performance liquid chromatography coupled to ion-mobility mass spectrometry

“…S1)54. The high-resolution precursor ion m/z , isotope abundance ratio, MS/55, and drift time were also used for the identification.…”

A Facile Technique of Sensing Adulteration in Emulsion: A Road to Safety

“…Several reports of adulteration in milk have been reported recently [1][2][3][4][5][6][7][8][9]. The common chemicals adulterants, which have been reported in milk, are sodium hydroxide, formalin, hydrogen peroxide, cane sugar, starch, gelatine, synthetic dyes, soap detergents and urea [10][11][12][13][14][15][16][17][18]. Among them, urea is frequently used in raw milk as per reports [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19].…”

“…The typical concentration of urea in milk is 18-40 mg/dl [1,4,[9][10][11][12][13]. Urea is a normal constituent of milk and it is a major part (55%) of the non-protein nitrogen of milk.…”

“…Recently several methods for melamine detection, including chromatographic methods [9][10][11][12][13][14], which consume much time to get the species analysed and are too tedious and expensive to be used. Also highperformance liquid chromatography and potentiometric and electrochemical methods are time consuming, are expensive and need trained people [4][5][6][7][8].…”

“…Also highperformance liquid chromatography and potentiometric and electrochemical methods are time consuming, are expensive and need trained people [4][5][6][7][8]. Some authors have also proposed nanotechnology based methods [9][10][11]. In the current study, we aim to synthesize gold nanoparticles (AuNPs) and exploit them for visual detection of urea in milk as a colorimetric probe.…”