Table 8.

Subgroup analyses of the effect of covariates of grape pomace on feed conversion ratio of broiler chickens.

Subgroup			Random Effects			Heterogeneity
	Nc		SMD	95 % CI	p-value	I2 (%)	p-value
Strain
Ross	21		0.05	−0.08, 0.18	0.463	54.6	0.001
Cobb	26		−0.04	−0.30, 0.22	0.786	89.8	< 0.001
Inclusion (g/kg)
1-10	9		−0.14	−0.29, −0.001	0.049	37.8	0.116
11-20	11		−0.01	−0.14, 0.12	0.894	0	0.891
21-30	10		0.16	−0.06, 0.38	0.160	63.3	0.004
41-50	3		−0.29	−0.51, −0.06	0.012	0	0.539
51-60	6		0.09	−0.70, 0.90	0.821	93.9	<0.001
>60	8		0.03	−0.73, 0.80	0.932	95.7	<0.001
Age (days)
1-21	14	0.32		−0.01, 0.64	0.056	81.6	<0.001
1-28	3	−0.001		−.0.23, 0.23	0.991	52.7	0.121
1-42	28	−0.14		−0.34, 0.05	0.156	86.0	<0.001
22-42	2	0.03		−0.30, 0.36	0.871	0	0.347
Sex
Male	23	0.32		0.03, 0.43	0.023	77.5	<0.001
Mixed	24	−0.21		−0.41, −0.01	0.044	85.7	<0.001

Nc = number of comparisons; SMD = standardized mean differences; CI = confident interval; I² = Inconsistency index; p = probability difference.