Table 2.

Key metabolites that differentiate serum of enriched piglets (ENR) from control (CTR) piglets at post-weaning period. P-values were derived from Student’s t-test. Variable importance in the projection (VIP) value was derived from OPLS-DA with a threshold of 0.75.

1H Chemical shift ppm (Central bucket point)	Metabolite	Moieties	KEEG IDs	ENR versus CTR
				Fold Change CTR/ENR	P-value	VIP
1.30	Lipidsa	$-({\mathrm{CH}}_2{)}_n-$	NA	2.7	0.021	2.09
1.26	Lipidsa	$-({\mathrm{CH}}_2{)}_n-$	NA	2.9	0.024	1.97
0.90	VLDL	${\mathrm{CH}}_3^{\ast }{\mathrm{CH}}_2{\mathrm{CH}}_2\mathrm{C}=$	NA	2.6	0.014	1.25
5.30	Unsaturated lipids	$-\mathrm{CH}=\mathrm{CH}-$	NA	3.6	0.027	1.17
2.02	Unsaturated lipids	$-{\mathrm{CH}}_2^{\ast }-\mathrm{CH}=\mathrm{CH}-$	NA	1.7	0.039	1.12
0.86	LDL	${\mathrm{CH}}_3^{\ast }({\mathrm{CH}}_2{)}_n-$	NA	1.9	0.018	1.09
3.94	Creatine	$-{\mathrm{CH}}_2-$	C00300	1.5	0.006	0.82
1.58	Lipidsa	$-{\mathrm{CH}}_2^{\ast }{\mathrm{CH}}_2\mathrm{CO}-$	C06104	4.7	0.033	0.77

^aTriglycerides and fatty acids.

VLDL: very low-density lipoprotein; LDL: low density lipoprotein.