. 2023 Mar 16;102(6):102653. doi: 10.1016/j.psj.2023.102653

Table 2.

Effect of guanidinoacetic acid (GAA) supplementation on breast muscle creatine metabolism, energy metabolites, malondialdehyde (MDA) concentration, and antioxidant enzyme activities (superoxide dismutase, SOD, and glutathione peroxidase, GPx) of male broilers subjected to heat stress in the finisher phase at d 26 and 39¹ (n = 12).

Item Supplemental GAA, g/kg	Dietary treatment²			SEM	P value
Item Supplemental GAA, g/kg	0.0	0.6	1.2	SEM	Model	Linear	Quadratic
ATP, μmol/g
d 26	5.9	6.1	5.9	0.14	0.703	0.898	0.410
d 39	6.6	6.6	6.4	0.11	0.472	0.387	0.388
Phosphocreatine, mg/kg
d 26	2351	2639	3119	143.9	0.085	0.029	0.784
d 39	4078^b	4558^ab	4750^a	105.6	0.016	0.005	0.532
Free creatine, mg/kg
d 26	3308	3815	3845	116.2	0.097	0.056	0.310
d 39	1341^b	1699^a	1818^a	56.6	0.001	<0.001	0.245
Total creatine, mg/kg
d 26	4769^b	5454^a	5782^a	116.2	<0.001	<0.001	0.357
d 39	3875^b	4500^a	4769^a	101.3	<0.001	<0.001	0.274
Phosphocreatine/ATP, μmol/μmol
d 26	1.9	2.1	2.6	0.13	0.080	0.033	0.488
d 39	3.0^b	3.3^ab	3.7^a	0.09	0.008	0.002	0.785
Glycogen, μmol/g
d 26	239^b	291^ab	306^a	10.2	0.016	0.006	0.373
d 39	277	305	305	7.1	0.172	0.102	0.353
MDA, nmol/g
d 26	7.1	5.9	7.0	0.40	0.433	0.920	0.202
d 39	7.0	6.9	7.8	0.36	0.561	0.384	0.517
SOD, U/g
d 26	29	28	27	0.5	0.156	0.057	0.803
d 39	30	28	26	0.6	0.049	0.015	0.781
GPx, U/g
d 26	0.36	0.33	0.35	0.01	0.608	0.688	0.365
d 39	0.52	0.51	0.50	0.01	0.837	0.562	0.906

Broilers were fed a corn-soybean starter diet from d 0 to 10, a grower diet from d 10 to 25, and a finisher diet from d 25 to 39.

Mean values with different superscripts (a, b) per sampling day are significantly different at P < 0.05.