TABLE 2.

The upregulated significantly differential metabolites (SDMs) in LW duck compared to MS duck (VIP value > 1, fold change>1.2 or fold change< 0.833, and p < 0.05).

SDMs	Formula	Molecular weight	Class	Fold Change	P	VIP
L-Ornithine	C5H12N2O2	132.16	Amino Acid And Its Derivatives	2.92	0.001	2.02
5-Hydroxylysine	C6H15ClN2O3	198.65	Amino Acid And Its Derivatives	2.06	0.002	1.42
Trimethyllysine	C9H21N2O2	189.275	Amino Acid And Its Derivatives	1.55	0.033	1.2
L-Lysine	C6H14N2O2	146.19	Amino Acid And Its Derivatives	1.58	0.037	1.39
L-Arginine	C6H14N4O2	174.2	Amino Acid And Its Derivatives	1.7	0.041	1.29
L-Canavanine	C5H12N4O3	176.174	Amino Acid And Its Derivatives	12.41	0.042	1.88
Indole-3-acetamide	C10H10N2O	174.2	Indole And Its Derivatives	1.69	0.017	1.39
Serotonin hydrochloride	C10H13ClN2O	212.677	Indole And Its Derivatives	12.41	0.046	1.82
Guanosine monophosphate	C10H14N5O8P	363.058	Nucleotide And Its Derivates	2.77	0.005	1.65
Deoxyribose 5-Phosphate	C5H11O7P	214.11	Nucleotide And Its Derivates	1.48	0.009	1.97
Xanthosine	C10H12N4O6	284.225	Nucleotide And Its Derivates	1.84	0.024	1.7
CDP	C9H15N3O11P2	403.176	Nucleotide And Its Derivates	3.41	0.026	1.54
Isobutyrylglycine	C6H11NO3	145.156	Organic Acid And Its Derivatives	1.48	0.013	1.76
Homotaurine	C3H9NO3S	139.17	Organic Acid And Its Derivatives	1.74	0.024	1.35
Allantoin	C4H6N4O3	158.12	Organoheterocyclic compounds	1.92	0.005	1.8
Trimethylamine N-oxide	C3H9NO	75.11	Polyamine	2.57	0.014	1.4