Table 7.

Description of the major principal components obtained by principal component analysis (PCA) of 20 variables characterizing creatine metabolism and energy metabolites in male broilers subjected to heat stress in the finisher phase at d 39¹.

Principal component	1	2	3	4	5
Eigenvalues	5.4	2.0	1.9	1.7	1.7
% variance explained	27.2	10.2	9.4	8.7	8.3
% cumulative	27.2	37.4	46.9	55.6	63.8
Means for treatments2, supplemental GAA, g/kg
0.0	−0.85c	0.14	−0.16	0.12	−0.14
0.6	0.01b	−0.11	−0.08	0.10	−0.34
1.2	0.84a	−0.04	0.23	−0.21	0.48
SEM	0.17	0.17	0.17	0.17	0.17
P value	<0.001	0.826	0.619	0.679	0.107
Guanidinoacetic acid, plasma	0.74
Creatine, plasma	0.89
Homocysteine, plasma		0.77
Arginine, plasma	0.74
Creatine kinase, plasma			0.64
Lactate, plasma				0.50	0.46
Cholesterol, plasma			−0.58
Triglycerides, plasma		0.76	−0.40
Glucose, plasma				0.70
ATP, breast muscle					−0.72
Phosphocreatine, breast muscle	0.74
Free creatine, breast muscle	0.75
Total creatine, breast muscle	0.87
Glycogen, breast muscle	0.52		−0.40
Creatine, liver			0.40
Creatinine, liver	0.74
GAA, liver	−0.43	−0.46
Creatine, kidney	0.61
Creatinine, kidney			0.42
GAA, kidney				0.58

¹Broilers 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.

²Values with different superscripts (a–c) within a column are significantly different at P < 0.05.