Table 3. Effect of levels of cottonseed oil (CO) with or without addition of ferrous sulfate (FS) on feed intake, weight gain, and feed conversion of broilers from 1 to 7 and 1 to 21 days of age.

Main effect	FI	WG	FC	FI	WG1	FC2
CO (%)	1 to 7 days (Kg)			1 to 21 days (Kg)
0	0.100	0.094	1.069	1.026	0.686	1.498
2	0.104	0.094	1.118	1.046	0.708	1.481
4	0.103	0.096	1.084	1.067	0.742	1.441
6	0.100	0.093	1.082	1.053	0.729	1.448
FS*
Without	0.102	0.099A	1.034B	1.058	0.726	1.461
With	0.101	0.089B	1.142A	1.036	0.704	1.473
CV (%)	5.00	5.45	6.90	4.00	5.45	3.40
Source of variation	Probability > F
FS	0.853	0.0001	0.0001	0.128	0.136	0.499
CO	0.135	0.652	0.503	0.201	0.007	0.029
CO × FS	0.232	0.904	0.377	0.660	0.398	0.386

FI, feed intake; WG, weight gain; FC, feed conversion; CV, coefficient of variation;

*Means with common uppercase letters in the column do not differ statistically according to the SNK test (p<0.05);

¹Linear effect (WG = 0.690 + 0.008CO, R² = 0.76).

² Linear effect (FC = 1495,5–0.00939CO, R² = 0.82)