Table 8.

Occurrence of Wooden Breast (%) 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)
Normal	T – 21	38.75	44.16	50.89	40.45	47.05	41.55	43.81	2.743	0.4500	0.0439	0.8270
	T – 42	42.86	30.36	37.91	35.92	34.20	44.23	37.58	1.972	0.4096		0.3191
Light	T – 21	26.25	20.74	23.21	20.74	21.57	21.63	22.36	1.674	0.9893	0.9859	0.9408
	T – 42	16.96	22.32	10.78	24.45	24.31	20.81	19.94	2.001	0.8637		0.3374
Moderate	T – 21	20.00	20.81	16.07	20.88	21.57	23.35	20.45	1.759	0.7814	0.9073	0.9145
	T – 42	22.32	25.00	24.31	23.56	19.85	17.03	22.01	1.818	0.7889		0.8196
Severe	T – 21	15.00	14.29	9.82	17.93	9.82	13.46	13.39	1.531	0.3728	0.0421	0.6420
	T – 42	17.86	22.32	26.99	16.07	21.63	17.93	20.47	2.23	0.7819		0.7687

L, linear; Q, Quadratic.

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.