Table 8.

Effect of strain (Cobb or Ross), sex (Male or Female) on white striping (WS), wooden breast (WB), bursal meter score (BSM), tibial dyschondroplasia (TD), and percentage of positive broilers with burned feed (BF), femoral head necrosis (FH), and thymus at 42 d of age.

Strain	Sex	WS	WB	BSM	TD	BF∗	FH∗	Thymus∗
		(1–4)		(1–9)	(0–3)	(% +)	(% +)	(% +)
Cobb		1.87	2.25	1.28	0.10	2.6	35.9	12.8
Ross		2.00	2.80	1.18	0.15	7.5	32.5	7.5
P <		0.387	<0.001	0.327	0.546	0.321	0.715	0.431
	Male	2.12	2.73	1.10	0.18	5.0	40.0	5.0
	Female	1.75	2.33	1.36	0.08	5.1	28.2	15.4
	P <	0.011	0.013	0.022	0.245	1.0	0.286	0.131
Cobb	Female	1.65	2.15	1.37	0.05	0.0	36.8	15.8
Cobb	Male	2.10	2.35	1.20	0.15	5.0	35.0	10.0
Ross	Female	1.85	2.50	1.35	0.10	10.0	45.0	0.0
Ross	Male	2.15	3.10	1.00	0.20	5.0	20.0	15.0
	P <	0.604	0.209	0.415	0.987	0.320	0.216	0.501
Model Pooled SEM1		0.14	0.16	0.11	0.08	.	.	.

^abMeans within a column of 3 or more independent variables lacking a common superscript differ significantly (P < 0.05, ∗Prob > ChiSq).

¹SEM = Standard error of mean, main effect means of strain and sex calculated using n = 40, interaction effect means calculated using n = 20.