TABLE 1.

Differences in relative abundances of bacterial families present in ileal and cecal digesta of low- and high-RFI broiler chickens fed either ad libitum or restrictively^a

Family	% Relative abundance				SEM	P value
	Ad libitum feeding		Restrictive feeding
	Low RFI	High RFI	Low RFI	High RFI		FL	RFI	FL × RFI
Ileum
o__Clostridiales;f__	3.58	0.83	6.83	11.27	4.229	0.112	0.843	0.400
f__Turicibacteraceae	42.20	48.27	29.06	27.85	8.661	0.058	0.780	0.676
f__Ruminococcaceae	0.95	0.22	4.49	2.47	1.642	0.084	0.408	0.695
f__Enterobacteriaceae	37.49	22.83	17.74	11.14	7.155	0.033	0.143	0.576
f__Lactobacillaceae	9.38	22.13	35.34	33.30	9.064	0.046	0.557	0.419
f__Lachnospiraceae	0.22	0.063	0.76	0.49	0.284	0.096	0.453	0.832
f__Peptostreptococcaceae	3.65	3.50	2.56	6.15	1.699	0.647	0.316	0.277
f__Clostridiaceae	2.15	1.83	2.60	6.62	2.247	0.249	0.414	0.339
o__RF39;f__	0.023	0.008	0.060	0.071	0.033	0.134	0.949	0.700
f__Christensenellaceae	0.050	0.0012	0.091	0.036	0.039	0.330	0.185	0.934
f__Bacillaceae	0.062	0.018	0.090	0.044	0.047	0.560	0.337	0.989
o__Streptophyta;f__	0.13	0.10	0.23	0.18	0.086	0.289	0.665	0.912
o__Clostridiales; Other	0.025	0.028	0.019	0.033	0.009	0.942	0.342	0.559
f__Dehalobacteriaceae	0.0004	0	0.016	0.005	0.005	0.054	0.292	0.336
f__Erysipelotrichaceae	0.005	0.006	0.007	0.014	0.004	0.281	0.419	0.436
f__Coriobacteriaceae	0.113	0.100	0.090	0.060	0.019	0.103	0.258	0.673
f__Enterococcaceae	0.037	0.031	0.027	0.071	0.0181	0.394	0.298	0.172
f__Corynebacteriaceae	0.0006	0.007	0.003	0.078	0.0351	0.296	0.252	0.329
Ceca
o__Clostridiales;f__	51.67	51.87	65.29	66.09	3.217	<0.001	0.876	0.926
f__Turicibacteraceae	0.35	0.97	0.12	0.016	0.228	0.012	0.263	0.119
f__Ruminococcaceae	29.00	29.54	23.37	25.23	2.358	0.040	0.614	0.781
f__Enterobacteriaceae	7.82	6.62	2.34	0.90	1.571	<0.001	0.406	0.940
f__Lactobacillaceae	0.96	0.73	1.17	1.11	0.326	0.373	0.662	0.798
f__Lachnospiraceae	7.94	7.65	5.24	4.16	0.978	0.003	0.487	0.688
f__Peptostreptococcaceae	0.062	0.048	0.022	0.010	0.011	<0.001	0.160	0.906
f__Clostridiaceae	0.18	0.41	0.04	0.06	0.129	0.059	0.348	0.400
o__RF39;f__	0.61	0.90	1.00	0.69	0.190	0.648	0.975	0.117
f__Christensenellaceae	0.52	0.17	0.65	0.49	0.123	0.079	0.047	0.427
f__Bacillaceae	0.38	0.42	0.19	0.76	0.179	0.661	0.095	0.142
o__Streptophyta;f__	0	0	0	0.0008	0.0004	0.339	0.308	0.339
o__Clostridiales; Other	0.072	0.106	0.104	0.078	0.031	0.938	0.887	0.343
f__Dehalobacteriaceae	0.084	0.079	0.135	0.136	0.019	0.007	0.938	0.863
f__Erysipelotrichaceae	0.086	0.165	0.072	0.073	0.033	0.113	0.226	0.243
f__Coriobacteriaceae	0.005	0.006	0.007	0.014	0.004	0.281	0.419	0.436
f__Enterococcaceae	0.005	0.005	0.002	0.003	0.003	0.069	0.753	0.615
f__Corynebacteriaceae	0	0.000003	0	0.0006	0.0002	0.150	0.145	0.150

^aData are presented as least-squares means and pooled standard errors of the means (SEM). n = 7 per FL group, residual-feed-intake (RFI) rank, and sex except for n = 8 high-RFI ad libitum females. RFI was calculated for the experimental period from 9 to 30 days posthatch. FL, feed intake level.