Table 6.

Effect of β-alanine on the metabolic concentration of amino acids in the plasma of Yili horses 2 h after the race (μmol/L).

Items	Control groups	Test groups
Gly	316.00 ± 72.16	403.17 ± 99.20
Ala	371.67 ± 137.26	335.33 ± 113.53
Gln	283.67 ± 36.97	298.83 ± 49.09
Val	232.67 ± 23.85A	158.50 ± 15.31B
Ser	165.50 ± 24.44	148.00 ± 32.85
Pro	117.28 ± 42.71	118.10 ± 22.59
Leu	99.65 ± 15.01A	63.03 ± 9.94B
Arg	75.68 ± 14.87	79.50 ± 16.83
Cit	78.07 ± 35.72	66.48 ± 26.47
Lys	78.72 ± 16.69a	58.77 ± 10.97b
Orn	56.78 ± 12.45	50.62 ± 13.64
Ile	65.23 ± 11.36A	41.70 ± 6.28B
His	62.17 ± 11.05	56.40 ± 10.81
Thr	63.82 ± 7.22a	53.05 ± 7.57b
Phe	48.62 ± 6.07	49.53 ± 6.16
Tyr	43.95 ± 8.67	41.13 ± 6.02
Trp	39.08 ± 4.43	36.62 ± 4.25
Glu	32.38 ± 6.58	35.8 ± 13.17
Tau	23.66 ± 10.50	26.17 ± 12.96
β-Ala	4.13 ± 1.05B	27.47 ± 17.83A
Asn	22.90 ± 5.38	18.1 ± 5.00
Met	19.97 ± 2.80	21.78 ± 4.80
Hyp	15.73 ± 2.23	15.70 ± 3.89
Hpro	12.02 ± 7.67	10.76 ± 2.33
3MHis	8.43 ± 0.97b	13.52 ± 5.41a
Asp	6.93 ± 2.94	8.74 ± 4.59
Car	7.77 ± 2.06b	11.12 ± 2.79a
Abu	2.76 ± 0.70	2.38 ± 0.41
Kyn	2.09 ± 0.47b	2.62 ± 0.28a
Cys1	1.91 ± 1.24	1.50 ± 0.52
Ans	1.33 ± 0.37	1.59 ± 0.53
EtN	1.59 ± 0.90	1.68 ± 1.09
Harg	1.04 ± 0.19	1.01 ± 0.18
Aad	0.97 ± 0.26	1.00 ± 0.58
Sar	0.75 ± 0.12	0.8 ± 0.32
3-Aib	0.71 ± 0.15	0.90 ± 0.29
5-HT	0.8 ± 0.31	1.66 ± 2.46
Asa	0.25 ± 0.15	0.36 ± 0.46
Hcit	0.28 ± 0.17	0.3 ± 0.31
5-HTP	0.18 ± 0.19	0.06 ± 0.15
PEtN	0.27 ± 0.35	--
5-Ava	0.26 ± 0.22	0.29 ± 0.22
Cth	0.04 ± 0.10b	0.24 ± 0.16a
Hyl	0.20 ± 0.15	0.18 ± 0.19
GABA	0.24 ± 0.09	0.28 ± 0.11
Hser	0.02 ± 0.03	0.04 ± 0.07

^a,bValues within a row without common superscripts differ significantly (p < 0.05). ^A,BValues in rows with no common superscript, highly significant (p < 0.01).