Table 4.

Effect of guanidinoacetic acid (GAA) supplementation on protein and amino acids in plasma of male broilers subjected to chronic cyclic heat stress in the finisher phase at day 26 and 39.¹

Item	Dietary treatment			Pooled SEM	P-value
Supplemental GAA, g/kg	0.0	0.6	1.2		Model	Linear	Quadratic
Uric acid, mmol/l
Day 26	342	320	271	15.1	0.147	0.057	0.666
Day 39	233	274	251	9.2	0.184	0.409	0.100
Albumin, g/l
Day 26	11	10	10	0.2	0.196	0.096	0.483
Day 39	10	10	10	0.1	0.783	0.903	0.494
Total protein, g/l
Day 26	30	28	28	0.5	0.315	0.217	0.376
Day 39	28	29	28	0.4	0.816	0.718	0.602
Alanine, μmol/L
Day 26	768	761	692	29.5	0.521	0.304	0.626
Day 39	452	445	442	15.9	0.967	0.800	0.963
α-Aminobutyric acid μmol/L
Day 26	18	16	18	0.8	0.657	0.987	0.363
Day 39	14	13	13	0.5	0.896	0.671	0.851
Arginine, μmol/L
Day 26	263b	311a,b	344a	12.8	0.029	0.009	0.752
Day 39	226	271	302	16.9	0.185	0.070	0.847
Aspargine, μmol/L
Day 26	106	118	98	8.1	0.592	0.628	0.357
Day 39	46	74	63	6.2	0.172	0.256	0.132
Aspartic acid, μmol/L
Day 26	74	74	68	6.2	0.912	0.727	0.808
Day 39	91	81	78	3.4	0.264	0.124	0.596
Carnosine, μmol/L
Day 26	54	44	47	2.4	0.243	0.264	0.206
Day 39	54a	40b	46a,b	1.9	0.012	0.100	0.011
Citrulline, μmol/L
Day 26	5.4	6.8	6.8	0.48	0.438	0.272	0.509
Day 39	9.1	10.9	9.4	0.51	0.293	0.759	0.127
Cystine, μmol/L
Day 26	46	49	46	1.5	0.628	0.975	0.339
Day 39	51	54	51	1.5	0.430	0.897	0.200
Glutamine, μmol/L
Day 26	883	929	783	33.7	0.196	0.224	0.179
Day 39	806	806	804	21.2	0.342	0.970	0.146
Glutamic acid, μmol/L
Day 26	187	177	158	6.7	0.204	0.080	0.793
Day 39	177	176	181	3.6	0.843	0.682	0.681
Glycine, μmol/L
Day 26	384	413	375	12.9	0.466	0.776	0.232
Day 39	349b	411a	387a,b	10.2	0.039	0.113	0.041
Histidine, μmol/L
Day 26	38	34	38	1.1	0.306	0.985	0.127
Day 39	39	41	43	1.5	0.581	0.301	0.967
Hydroxyproline, μmol/L
Day 26	145	174	158	6.2	0.164	0.384	0.090
Day 39	156	137	148	6.1	0.472	0.610	0.267
Isoleucine, μmol/l
Day 26	60	55	63	2.5	0.443	0.702	0.226
Day 39	67	76	66	2.9	0.343	0.958	0.147
Leucine, μmol/L
Day 26	157	151	170	6.1	0.452	0.387	0.361
Day 39	169	179	152	5.4	0.133	0.195	0.120
Lysine, μmol/L
Day 26	120	90	102	6.6	0.191	0.278	0.142
Day 39	165	151	141	18.9	0.595	0.314	0.921
Methionine, μmol/L
Day 26	60	65	64	2.4	0.725	0.551	0.596
Day 39	62	74	67	3.0	0.286	0.471	0.159
Ornithine, μmol/L
Day 26	22	21	23	1.1	0.704	0.943	0.407
Day 39	26	33	25	2.0	0.227	0.907	0.088
Phenylalanine, μmol/L
Day 26	96	90	96	2.4	0.487	0.953	0.229
Day 39	109	119	112	4.5	0.246	0.647	0.109
Proline, μmol/L
Day 26	334	336	344	13.9	0.948	0.759	0.914
Day 39	237	235	234	8.7	0.989	0.882	0.977
Serine, μmol/L
Day 26	505	522	434	20.9	0.194	0.166	0.239
Day 39	412	454	449	11.4	0.261	0.185	0.334
Taurine, μmol/L
Day 26	155	217	185	14.9	0.240	0.407	0.141
Day 39	105	91	101	8.5	0.800	0.851	0.334
Threonine, μmol/L
Day 26	429	415	393	18.3	0.721	0.928	0.425
Day 39	339	357	375	22.8	0.509	0.249	0.999
Tryptophan, μmol/L
Day 26	67	59	63	1.9	0.325	0.429	0.203
Day 39	82	88	83	1.9	0.341	0.936	0.146
Tyrosine, μmol/L
Day 26	131	155	150	6.1	0.245	0.250	0.219
Day 39	142	150	153	8.9	0.871	0.614	0.893
Valine, μmol/L
Day 26	95	88	102	3.1	0.197	0.352	0.122
Day 39	103	111	95	4.1	0.309	0.459	0.181

^a,bMeans within a row lacking a common superscript letter differ (P <0.05).

¹Broilers were fed a corn–soybean starter diet from day 0 to 10, a grower diet from day 10 to 25, and a finisher diet from day 25 to 39. Values are means of 12 replicate chickens.