Metabolic Profile in Multiple Tissues Associated with Feed Efficiency on Steers

A study of multiple tissues was conducted to identify potential metabolic differences in cattle differing in feed efficiency. Individual feed intake and BW was measured on 144 steers during 105 d on a high concentrate ration. Steers were selected according to differences in ADG (P = 0.01) with those with the greatest ADG (n=8; 1.96 ± 0.02 kg/d) and least ADG (n=8; 1.57 ± 0.02 kg/d), yet that did not differ in DMI (10.10 ± 0.05 kg/d; P=0.41), used. Duodenum, liver, adipose, and longissimus dorsi were collected at slaughter. Metabolomics profiles of the 4 tissues were conducted using ultra-performance liquid chromatography, time-of-flight mass spectrometry. Principal components analyses, t-tests (P < 0.05) and fold changes in tissue profiles were used to identify differential metabolites between ADG groups (metabolites identified: n = 85 in duodenum; n = 96 in liver; n = 87 in longissimus dorsi; n = 72 in adipose). Of all metabolites identified, none were identified in all 4 tissues. However, some metabolites were found in 3 of the tissues. These were primarily involved in alpha-linolenic metabolism, which were down-regulated in the greatest-ADG as compared to least-ADG group in duodenum, adipose, and longissimus-dorsi (impact-value 1.0; P < 0.05). In contrast, taurine and hypotaurine (impact-value 0.75; P = 0.10) and glycerophospholipids metabolisms (impact-value 0.34; P < 0.01) were both up-regulated in the greatest-ADG compared with least-ADG group in the liver. Despite the distinctive metabolites profile of each tissue, these findings provided evidence of common biochemical pathways across tissues related to difference in 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. USDA is an equal opportunity provider and employer.