Table 6.

Woody breast myopathy (WBM) severity probabilities of 5 strains of broilers fed control or amino acid–reduced diet (with digestible lysine, TSAA, and threonine being 20% lower than the control diet) on day 42 and 56.

Treatment		WBM severity day 42 (probability)					WBM severity day 56 (probability)
Strain	Diet	Normal	Slight	Moderate	Severe	Significance1	Normal	Slight	Moderate	Severe	Significance1
Strain 1		0.26	0.41	0.24	0.09	b,c	0.16	0.40	0.29	0.15
Strain 2		0.13	0.32	0.36	0.19	a	0.08	0.27	0.35	0.30
Strain 3		0.44	0.38	0.14	0.04	d	0.15	0.38	0.30	0.17
Strain 4		0.38	0.40	0.17	0.05	c,d	0.36	0.42	0.16	0.06
Strain 5		0.17	0.37	0.32	0.14	a,b	0.08	0.29	0.36	0.27
	Control	0.18	0.38	0.31	0.13	a	0.10	0.30	0.35	0.25
	Reduced	0.35	0.40	0.19	0.06	b	0.22	0.42	0.25	0.11
Strain 1	Control	0.23	0.40	0.27	0.10		0.12	0.36	0.32	0.20	b,c
Strain 1	Reduced	0.29	0.41	0.23	0.07		0.21	0.42	0.26	0.11	c
Strain 2	Control	0.12	0.31	0.37	0.20		0.07	0.26	0.36	0.31	b
Strain 2	Reduced	0.14	0.33	0.36	0.17		0.08	0.28	0.35	0.29	b
Strain 3	Control	0.35	0.41	0.18	0.06		0.14	0.37	0.31	0.18	b,c
Strain 3	Reduced	0.53	0.34	0.10	0.03		0.16	0.39	0.29	0.16	b,c
Strain 4	Control	0.19	0.39	0.3	0.12		0.20	0.41	0.26	0.13	c
Strain 4	Reduced	0.60	0.30	0.08	0.02		0.56	0.33	0.08	0.03	d
Strain 5	Control	0.10	0.28	0.38	0.24		0.03	0.13	0.29	0.55	a
Strain 5	Reduced	0.27	0.42	0.23	0.08		0.23	0.42	0.24	0.11	c
P-value	Strain					<0.0001					<0.0001
	Diet					<0.0001					<0.0001
	Strain × diet					0.073					0.002

^1a–dLeast squares means in a column not sharing a common superscript were different among treatments (P < 0.05); a to d represents the order of woody breast myopathy (WBM) severity probability from the most to least severe.