. 2022 May 13;101(8):101963. doi: 10.1016/j.psj.2022.101963

Table 4.

Pectoralis major muscle myopathy distribution of broilers reared under different environmental conditions and feed regimens from 20 to 41 d and processed at 42 d.

Parameter	Score	Treatment¹				SEM²	P-values
Parameter	Score	TN-al	cyHS	coHS	TN-coPF	SEM²	P-values
Woody Breast³ (%)	Normal	28.81^c	69.67^b	87.54^a	100.00^a	7.1071	<0.001
	Mild	67.74^a	30.33^b	12.46^c	0.00^c	7.6967	<0.001
	Severe	3.45	0.00	0.00	0.00	1.9956	0.073
White Striping⁴ (%)	Normal	1.67^c	2.13^c	32.67^b	83.99^a	4.8876	<0.001
	Faint	93.33^a	94.70^a	67.33^b	16.01^c	6.0797	<0.001
	Apparent	5.00	3.17	0.00	0.00	3.7671	0.215

TN-al: Birds reared under continuous 24°C and ad libitum feeding. cyHS: Birds reared under cyclic high temperature (8 h at 35˚C and 12 h at 24˚C) and ad libitum feeding. coHS: Birds reared under continuous 35°C and ad libitum feeding. TN-coPF: Birds reared under continuous 24°C and pair-fed to the coHS treatment.

SEM: pooled standard error of the mean.

P. major fillets were considered normal, mild, or severe for woody breast if the fillet was flexible throughout, stiff in cranial region, or if stiff in the cranial and caudal regions, respectively.

⁴

P. major fillets were considered normal, faint, or apparent for white striping if they displayed no visible stripes, stripes less than 1 mm, or stripes larger than 1 mm, respectively.

^a-b

Means within row without a common superscript were determined to be significantly different (P < 0.05) by a Tukey's multiple comparison test.