Table 5. Relative concentrations of metabolites in plasma acquired by ¹H-nuclear magnetic resonance (¹H-NMR) spectroscopy from short-term exposure to heat stress or thermal-neutral conditions in growing pigs

Item	Treatment¹⁾				SEM	p-value
Item	TN(-1D)	HS	TN(2D)	TN(5D)	SEM	p-value
Acetate	0.73	0.60	0.95	0.96	0.07	0.193
Alanine	3.09^b	3.34^b	4.42^a	3.57^ab	0.15	0.034
Arginine	1.53	2.06	2.08	2.09	0.13	0.379
Betaine	2.98	2.88	3.11	3.59	0.14	0.303
Citrate	0.76	1.16	0.92	0.86	0.07	0.290
Creatine	2.03	2.75	1.73	2.15	0.17	0.215
Creatinine	0.31^b	0.58^a	0.38^b	0.36^b	0.02	0.002
Formate	0.80	0.96	1.05	0.97	0.07	0.690
Glucose	27.89	30.68	29.59	29.32	1.00	0.804
Glutamate	1.10	1.62	1.06	0.95	0.13	0.307
Glutamine	2.30	2.95	3.02	2.64	0.15	0.315
Glycine	5.82	6.24	7.27	6.88	0.30	0.353
Isoleucine	0.84	1.16	1.14	1.14	0.05	0.115
Lactate	38.62	28.52	28.92	30.27	1.66	0.138
Leucine	1.08^b	1.16^ab	1.59^a	1.54^a	0.07	0.038
Lysine	0.70	0.86	1.06	0.99	0.05	0.117
Methionine	0.14	0.18	0.21	0.16	0.01	0.136
Phenylalanine	0.56	0.82	0.59	0.63	0.05	0.242
Proline	2.12	3.16	3.02	3.29	0.18	0.113
Pyruvate	1.22	1.30	1.11	1.04	0.05	0.288
Serine	1.35	1.61	1.53	1.48	0.08	0.701
Threonine	1.49	1.96	1.81	1.56	0.10	0.350
Tyrosine	0.74	1.03	0.85	0.98	0.05	0.245
Valine	1.79	2.43	2.61	2.58	0.12	0.071

TN(-1D), thermal-neutral condition; HS, heat stress condition; TN(2D), 2 d of thermal-neutral recovery; TN(5D), 5 d of thermal-neutral recovery.
Mean values with Duncan analysis (p < 0.05).