Plasma Carboxyl-Metabolome Is Associated with Average Daily Gain Divergence in Beef Steers.

Ibukun Ogunade,Bremansu Osa-Andrews,Sunday Peters,Adeoye Oyebade

doi:10.3390/ani11010067

Abstract

Simple SummaryIn this study, we analyzed the plasma carboxyl-metabolome in beef steers with divergent average daily gain (ADG). Several short chain fatty acids were greater in beef steers with greater ADG. Conversely, several long chain fatty acids were greater in beef steers with lower ADG. Pathway analysis of the differential metabolites revealed alterations in abundance/activities of enzymes involved in fatty acid metabolism in the liver. The results of this study demonstrated that beef steers with divergent ADG had altered plasma carboxyl-metabolome, which is possibly caused by altered abundances and/or activities of enzymes involved in fatty acid oxidation and biosynthesis.We applied an untargeted metabolomics technique to analyze the plasma carboxyl-metabolome of beef steers with divergent average daily gain (ADG). Forty-eight newly weaned Angus crossbred beef steers were fed the same total mixed ration ad libitum for 42 days. On day 42, the steers were divided into two groups of lowest (LF: n = 8) and highest ADG (HF: n = 8), and blood samples were obtained from the two groups for plasma preparation. Relative quantification of carboxylic-acid-containing metabolites in the plasma samples was determined using a metabolomics technique based on chemical isotope labeling liquid chromatography mass spectrometry. Metabolites that differed (fold change (FC) ≥ 1.2 or ≤ 0.83 and FDR ≤ 0.05) between LF and HF were identified using a volcano plot. Metabolite set enrichment analysis (MSEA) of the differential metabolites was done to determine the metabolic pathways or enzymes that were potentially altered. In total, 328 metabolites were identified. Volcano plot analysis revealed 43 differentially abundant metabolites; several short chain fatty acids and ketone bodies had greater abundance in HF steers. Conversely, several long chain fatty acids were greater in LF steers. Five enzymatic pathways, such as fatty acyl CoA elongation and fatty-acid CoA ligase were altered based on MSEA. This study demonstrated that beef steers with divergent ADG had altered plasma carboxyl-metabolome, which is possibly caused by altered abundances and/or activities of enzymes involved in fatty acid oxidation and biosynthesis in the liver.

Highlights

IntroductionPrevious studies applied metabolomics and metagenomics analysis of rumen microbiota as well as transcriptomics and proteomics analysis of liver to examine differences in average daily gain (ADG) and/or residual feed intake (RFI) in animals [2,3,4]; these studies involve invasive and time-consuming sample collection procedures
Principal component analysis plot showed no separation between the plasma carboxyl-metabolome of the LF and HF steers (Figure 1)
Blood metabolome metabolome represents represents aa functional functional read-out read-out of of overall overall metabolisms metabolisms in inthe the body; the changes in plasma carboxyl-metabolome observed in this study might have body; the changes in plasma carboxyl-metabolome observed in this study might originated from differences in ruminal microbial lipid metabolism and intestinal digestive have originated from differences in ruminal microbial lipid metabolism and intestinal diand absorptive capacity of the animals as well as non-dietary sources such as fatty acid gestive and absorptive capacity of the animals as well as non-dietary sources such as fatty metabolism in the liver, adipose tissue, and muscles [3,16]

Summary

Introduction

Previous studies applied metabolomics and metagenomics analysis of rumen microbiota as well as transcriptomics and proteomics analysis of liver to examine differences in average daily gain (ADG) and/or residual feed intake (RFI) in animals [2,3,4]; these studies involve invasive and time-consuming sample collection procedures. We applied a CIL/LC–MS-based metabolomics technique to examine differences in the plasma metabolites of beef steers divergent in ADG with a focus on those metabolites containing amine/phenol chemical groups [8]. Previous studies that studied transcriptomics and proteomics analysis of liver tissues identified fatty acid metabolism as the most important metabolic pathway associated with feed efficiency-related traits in animals [2,4,9]. This study applied CIL-LC-MS-based metabolomics to analyze carboxylic-acid-containing metabolites (carboxyl-metabolome), including fatty acid and their derivatives, in the plasma of beef steers divergent in ADG

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Discussion

Conclusion