Metabolomics comparison of rumen fluid and milk in dairy cattle using proton nuclear magnetic resonance spectroscopy

Abstract

Objective: The metabolites that constitute the rumen fluid and milk in dairy cattle were analyzed using proton nuclear magnetic resonance (<sup>1</sup>H-NMR) spectroscopy and compared with the results obtain for other dairy cattle herds worldwide. The aim was to provide basic dataset for facilitating research on metabolites in rumen fluid and milk.Methods: Six dairy cattle were used in this study. Rumen fluid was collected using a stomach tube, and milk was collected using a pipeline milking system. The metabolites were determined by <sup>1</sup>H-NMR spectroscopy, and the obtained data were statistically analyzed by principal component analysis, partial least squares discriminant analysis, variable importance in projection scores, and metabolic pathway data using Metaboanalyst 4.0.Results: The total numbers of metabolites in rumen fluid and milk were measured to be 186 and 184, and quantified as 72 and 109, respectively. Organic acid and carbohydrate metabolites exhibited the highest concentrations in rumen fluid and milk, respectively. Some metabolites that have been associated with metabolic diseases (acidosis and ketosis) in cows were identified in rumen fluid, and metabolites associated with ketosis, somatic cell production, and coagulation properties were identified in milk.Conclusion: The metabolites measured in rumen fluid and milk could potentially be used to detect metabolic diseases and evaluate milk quality. The results could also be useful for metabolomic research on the biofluids of ruminants in Korea, while facilitating their metabolic research.

Metabolic profiling of serum and urine in lactating dairy cows affected by subclinical ketosis using proton nuclear magnetic resonance spectroscopy

“…Blood samples collected and storage methods until 1 H-NMR spectroscopy analysis was determined as described by Kim et al [ 19 ] and Eom et al [ 20 ] methods. Urine samples collected and storage methods until 1 H-NMR spectroscopy analysis was determined as described by Kim et al [ 19 ] and Eom et al [ 20 ] methods.…”

“…The missing values were replaced by a value one-half of the minimum positive value from the original data. In addition, statistical analyses methods were determined as described by Kim et al [ 19 ] and Eom et al [ 20 ] methods. Univariate Student’s t -test were used to quantify difference between metabolite profiles of the serum and urine samples.…”

Effects of seaweed extracts on in vitro rumen fermentation characteristics, methane production, and microbial abundance

“…The VIP score exceeding 1.5 were selected as differentially expressed metabolites. Detail procedures of such analyses has been reported in a previous article 64 . The data of in vitro was statistically analyzed using the PROC MIXED procedure of SAS 9.4.…”

Metabolic Profiling of Rumen Fluid and Milk in Lactating Dairy Cattle Influenced by Subclinical Ketosis Using Proton Nuclear Magnetic Resonance Spectroscopy

“…Above all, research on ketosis has focused on ketone body metabolite concentrations in blood, milk, and urine [20][21][22]. Recently, metabolomics studies have been conducted by comparing biofluid metabolites from Korean native cattle (Hanwoo; Bos taurus coreanae), and lactating dairy cattle (Holstein species) using proton nuclear magnetic resonance ( 1 H-NMR) spectroscopy [23][24][25]. However, owing to the low number of studies using 1 H-NMR spectroscopy on lactating dairy cattle biofluid metabolites associated with ketosis metabolic diseases, more studies are required.…”