Table 5.

Effects of dietary graded creatine nitrate (CrN) supplementation on meat quality and textural characteristics of the Pectoralis major muscle of broilers.

Items	Treatments1					SEM	P value
	Control	GAA600	CrN300	CrN600	CrN900		ANOVA	Linear2	Quadratic2
Meat quality
pH45min	6.17	6.20	6.23	6.19	6.22	0.01	0.630	0.427	0.561
pH24h	5.86b	5.92a	5.90ab	5.93a	5.95a	0.01	0.015	<0.001	0.556
L* (lightness)	42.54	42.58	42.78	42.72	44.37	0.28	0.217	0.086	0.252
a* (redness)	1.41	1.37	1.29	1.30	1.33	0.07	0.976	0.738	0.629
b* (yellowness)	3.13	3.27	3.72	3.77	3.67	0.12	0.291	0.118	0.147
Drip loss (%)	2.69a	2.25b	2.26b	2.23b	2.36b	0.05	0.006	0.018	0.004
Cooking loss (%)	13.07	12.43	12.05	11.31	11.37	0.33	0.426	0.086	0.469
Shear force (N)	20.15	20.14	21.32	21.71	22.33	0.52	0.630	0.193	0.819
Textural characteristics
Hardness (N)	22.26	21.44	21.28	20.40	20.84	0.62	0.923	0.357	0.571
Cohesiveness (-)	0.46	0.43	0.45	0.43	0.43	0.01	0.676	0.174	0.751
Springiness (mm)	2.85	2.88	2.74	2.90	2.65	0.05	0.488	0.301	0.676
Gumminess (N)	11.08	10.18	10.63	9.11	9.61	0.33	0.388	0.047	0.468
Chewiness (mJ)	31.47	28.06	29.94	24.68	24.87	0.90	0.057	0.001	0.594

Abbreviations: pH_{45 min}, pH at 45 min postmortem; pH_24h, pH at 24 h postmortem.

^a,bDifferent letters in the mean value of the same row indicate a significant difference (P < 0.05). The data are represented as the mean value and pooled SEM (n = 6).

¹Control, basal diet; GAA₆₀₀, basal diet supplemented with 600 mg/kg guanidinoacetic acid (GAA); CrN₃₀₀, CrN₆₀₀, and CrN₉₀₀, basal diets supplemented with 300, 600, and 900 mg/kg creatine nitrate (CrN), respectively.

²Orthogonal polynomials were used to estimate the linear and quadratic effects of dietary CrN supplementation among the control, CrN₃₀₀, CrN₆₀₀, and CrN₉₀₀ groups.