Non-targeted metabolomics by 1H nuclear magnetic resonance spectroscopy; an interspecies comparison of milk between dromedary, giraffe and white rhinoceros with observations on blesbok

Abstract

Various researchers have shown that milk metabolomes differ between domestic species regarding metabolite composition as well as metabolic pathways of milk synthesis. We contribute to this knowledge by presenting data of wild mammals. Inter-species differences were noted; 3-fucosyllactose was only detected in the milk of dromedary, and N-phenylacetylglycine and UDP-N-acetylglucosamine only in giraffe. Hippurate and 2-oxaloacetate were absent from milk of dromedary; creatinine and glutamate from giraffe; nicotinamide from white rhinoceros; and dimethylamine, creatine, valine, acetone, fumarate and 2-oxaloacetate from blesbok. With MetaboAnalyst 6.0, 15 statistically important metabolites of dromedary, giraffe and white rhinoceros were identified for KEGG metabolic pathway enrichment. Twelve metabolic pathways were identified as important with a specialization within species. In the giraffe mammary cells, the amino sugar and nucleotide sugar metabolism was observed as active and the alanine, aspartate and glutamate metabolism as inactive. The glycerophospholipid metabolism seemed highly active in the white rhinoceros and the galactose metabolism active in both the dromedary and white rhinoceros. Milk was available from only two blesbok, but data is presented as observation.