Table 2.

Effect of strain (Ross or Cobb) and Sex (Male or Female) on weekly Body Weights (kg).

Strain2	Sex	Weekly Body Weight1
		0 d	7 d	14 d	21 d	28 d	35 d	42 d
		(kg/broiler)
Ross		0.038	0.16	0.58	1.25	1.73	2.44	3.24
Cobb		0.035	0.15	0.56	1.23	1.70	2.42	3.20
	Male	0.037	0.16	0.58	1.29	1.83	2.63	3.52
	Female	0.036	0.16	0.56	1.19	1.61	2.23	2.91
SEM3		0.000	0.002	0.004	0.012	0.015	0.016	0.020
Ross Male		0.038	0.16	0.60a	1.32a	1.85	2.66	3.55
Ross Female		0.037	0.16	0.56b	1.18c	1.61	2.22	2.92
Cobb Male		0.035	0.15	0.57b	1.26b	1.80	2.61	3.50
Cobb Female		0.035	0.15	0.55b	1.20c	1.61	2.23	2.90
SEM3		0.000	0.002	0.006	0.016	0.021	0.023	0.028
		(Probability > F)
Strain		<0.01	<0.01	<0.01	0.21	0.19	0.36	0.13
Sex		0.38	0.73	<0.01	<0.01	<0.01	<0.01	<0.01
Strain x Sex		0.10	0.30	0.02	0.02	0.24	0.16	0.60

Means within a column of 3 or more independent variables lacking a common superscript differ significantly (P < 0.05^a,b).

¹Main and interaction effect means calculated using total pen weight/number of birds per pen = BW (kg).

²Ross 708 and Cobb 500.

³SEM = Standard error of mean, main effect means of strain and sex calculated using n = 20.