Table 3.

Influence of feeding system, dietary adaptation period, and direct-fed microbial supplementation on growth performance

Item	Feeding system
	Conventionally fed				Naturally fed
	14 d		28 d		14 d		28 d			P-values2
	−DFM1	+DFM	−DFM	+DFM	−DFM	+DFM	−DFM	+DFM	SEM3	Syst	Adapt	DFM	Syst × adapt	Syst × DFM	Adapt × DFM	Syst × Adapt × DFM
Initial BW, kg	390	395	397	397	387	379	390	388	7.9	0.12	0.32	0.79	0.88	0.50	0.95	0.67
Final BW, kg	619	624	607	632	600	591	593	593	11.4	0.001	0.77	0.51	0.98	0.21	0.39	0.68
ADG, kg/d	1.64	1.63	1.53	1.70	1.48	1.42	1.50	1.39	0.048	<0.001	0.67	0.87	0.85	0.02	0.29	0.08
DMI, kg/d	11.2	11.3	11.4	11.6	11.0	11.3	11.2	11.4	0.28	0.48	0.31	0.41	0.87	0.78	0.98	0.86
DMI, % of BW/d	2.22	2.22	2.23	2.22	2.22	2.23	2.23	2.23	0.043	0.10	0.23	0.38	0.87	0.13	0.42	0.89
DMI variance, kg2	6.75	7.45	6.87	6.30	6.28	7.18	7.59	7.49	0.481	0.39	0.67	0.50	0.05	0.62	0.10	0.83
G:F	0.147	0.144	0.134	0.147	0.136	0.126	0.134	0.122	0.0039	<0.001	0.16	0.33	0.65	0.006	0.20	0.09

¹Direct-fed microbial; − = without, + = with.

²Syst = conventionally fed vs. naturally fed; Adapt = 14 vs. 28 d; DFM = −DFM vs. +DFM.

³Standard error of the mean for the Syst × Adapt × DFM interaction.