|Artegoitia, Virginia - Aarhus University|
|Lewis, Ronald - University Of Nebraska|
Submitted to: ACS Omega
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/14/2018
Publication Date: 2/22/2019
Citation: Artegoitia, V.M., Foote, A.P., Lewis, R.M., Freetly, H.C. 2019. Metabolomics profile and targeted lipidomics in multiple tissues associated with feed efficiency in beef steers. ACS Omega. 4:3973-3982. http://doi.org/10.1021/acsomega.8b02494.
DOI: https://doi.org/10.1021/acsomega.8b02494 Interpretive Summary: Metabolomics is an emerging powerful technology that measures a large number of molecules, in tissues or biofluids, providing insights into metabolic responses to a nutritional intervention or health condition in animals. Based on this approach, metabolic analysis in multiple tissues were conducted to provide evidence on physiological mechanisms involved in differences in weight-to-gain ratios in cattle. Individual feed intake and body weight was measured on 144 steers during 105 d on a finishing ration. At the end of the feeding study, steers were selected according to differences in average daily gain (ADG) with those with the greatest ADG and least ADG whose dry matter intake was similar. Intestine, liver, adipose and muscle samples were collected at slaughter, and metabolomics profiles were used to identify differential metabolites between ADG groups. Overall, lipid transport and oxidation were the main common metabolic mechanism involved in weight-gain differences at multiple metabolic levels of complexity in beef cattle notwithstanding the uniqueness of the molecular composition of each tissue. Both mechanisms were associated with the level of alpha-linolenic acid, phosphatidylcholine and cholesterol that could be considered as useful biomarkers (in other sample formats e.g., blood, plasma) for feed efficiency in beef cattle. Combining analyses of multiple tissues may offer a powerful approach for defining the molecular basis of differences in performance among cattle for key production attributes.
Technical Abstract: A study of multiple tissues was conducted to identify potential metabolic differences in cattle differing in feed efficiency. Individual feed intake and body weight was measured on 144 steers during 105 days on a high-concentrate ration. Steers were selected according to differences in average daily gain (ADG) with those with the greatest ADG (n = 8; 1.96 ± 0.02 kg/day) and least ADG (n = 8; 1.57 ± 0.02 kg/day), whose dry matter intake was within 0.32 SD of the mean intake (10.10 ± 0.05 kg/day). Duodenum, liver, adipose, and longissimus-dorsi were collected at slaughter, and metabolomics profiles were performed by ultra performance liquid chromatography quadrupole-time of-flight mass spectrometry. Principal components analyses, t-tests, and fold changes in tissues profile were used to identify differential metabolites between ADG groups. These were primarily involved in a-linolenic metabolism, which was downregulated in the greatest ADG as compared to least-ADG group in duodenum, adipose, and longissimus-dorsi. However, taurine and glycerophospholipids metabolisms were both upregulated in the greatest ADG compared with least-ADG group in the liver. The phospholipids and cholesterol were quantified in the tissues. Lipid transport and oxidation were the main common metabolic mechanisms associated with cattle feed efficiency. Combining analyses of multiple tissues may offer a powerful approach for defining the molecular basis of differences in performance among cattle for key production attributes.