Table 4.

Effect of β-alanine on the metabolic concentration of amino acids in the plasma of Yili horses 1 h before the race (μmol/L).

Items	Control groups	Test groups
Gly	345.00 ± 95.92	441.67 ± 82.43
Ala	378.50 ± 38.68A	244.67 ± 63.75B
Gln	270.67 ± 30.07	324.00 ± 55.97
Val	229.50 ± 18.45a	195.83 ± 29.03b
Ser	172.00 ± 31.70	179.83 ± 33.89
Pro	114.62 ± 20.08	109.00 ± 11.47
Leu	87.63 ± 10.49	84.60 ± 16.22
Arg	70.88 ± 12.21B	93.63 ± 11.21A
Cit	85.70 ± 41.38	71.28 ± 15.53
Lys	74.33 ± 10.24	74.38 ± 14.71
Orn	54.62 ± 9.89b	70.07 ± 10.49a
Ile	62.93 ± 9.58	56.22 ± 9.30
His	53.32 ± 9.52	63.07 ± 11.97
Thr	54.53 ± 8.01	58.35 ± 12.77
Phe	43.32 ± 3.92b	50.42 ± 4.36a
Tyr	40.12 ± 6.96	43.73 ± 4.89
Trp	34.72 ± 1.53	34.8 ± 4.98
Glu	31.7 ± 3.90	34.67 ± 4.59
Tau	25.98 ± 11.01	25.42 ± 7.13
β-Ala	3.95 ± 1.62B	39.88 ± 22.65A
Asn	19.27 ± 4.82	23.08 ± 5.10
Met	19.2 ± 2.42	20.63 ± 4.07
Hyp	14.17 ± 2.55	15.67 ± 3.06
Hpro	15.73 ± 10.60	13.64 ± 3.05
3-MHis	6.80 ± 1.37	11.26 ± 4.89
Asp	7.86 ± 2.57	9.41 ± 3.33
Car	6.50 ± 2.72	8.73 ± 2.11
Abu	2.91 ± 0.47	2.88 ± 0.51
Kyn	2.20 ± 0.52	2.55 ± 0.33
Cys1	2.58 ± 1.11	2.00 ± 0.47
Ans	2.15 ± 1.15	1.67 ± 0.96
EtN	1.40 ± 0.70	1.48 ± 0.53
Harg	1.31 ± 0.43	1.37 ± 0.22
Aad	1.04 ± 0.42	1.11 ± 0.41
Sar	0.83 ± 0.24	0.96 ± 0.22
3-Aib	0.63 ± 0.20	1.00 ± 0.44
5-HT	0.66 ± 0.15A	0.38 ± 0.09B
Asa	0.62 ± 0.54	0.24 ± 0.28
Hcit	0.30 ± 0.19	0.28 ± 0.23
5-HTP	0.25 ± 0.10	0.29 ± 0.14
PEtN	0.53 ± 0.97	--
5-Ava	0.25 ± 0.32	0.18 ± 0.21
Cth	0.14 ± 0.12	0.22 ± 0.11
Hyl	0.10 ± 0.15	0.15 ± 0.29
GABA	0.05 ± 0.06	0.11 ± 0.14
Hser	0.10 ± 0.07	0.05 ± 0.08

^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).