Table 6.

Average scores for Wooden Breast (WB) and White Striping (WS) in the breast meat of broiler chickens fed with diets containing different vitamin A supplementation.

		Vitamin A (IU/Kg)
	Supplementation1	0	6,000	16,000	26,000	36,000	46,000	Average2	SEM	P (Anova)	P (Test F)	P (Regression)
WS	T – 21	1.83	0.69	0.60	0.70	0.63	0.67	0.8520	0.0793	<0.0001	0.2154	<0.0001 (Q)
	T – 42	0.97	0.96	1.04	0.96	1.00	0.88	0.9684	0.0523	0.9725		0.6935
WB	T – 21	1.11	1.05	0.85	1.16	0.94	1.09	1.0341	0.0577	0.5996	0.0053	0.5432
	T – 42	1.15	1.39	1.40	1.20	1.29	1.09	1.2537	0.0623	0.3751		0.4096

L, linear; Q, Quadratic.

WS (T-21 d): 0.000000001164109 vit A² - 0.00006915 vit A + 1.50037; R²: 0.43; Vit. A for minimum response: 29,700; Minimum response: 0.4735.

¹T-21 d: birds supplemented with treatments in the period of the 4 to 21 days of age. T-42 d: birds supplemented with treatments in the period of the 4 to 42 days of age.

²Test F (P ≤ 0.05) for comparing the averages of vitamin A supplementation times.