Effect of antimicrobial growth promoter administration on the intestinal microbiota of beef cattle

Table 1 Mean terminal restriction fragment (T-RF) number for digesta and mucosal samples obtained from beef cattle administered (AS700) or not administered antimicrobial growth promoters (Control) ^a

Sample/location	AS700	Control	LSD^b	Total^c
Digesta
Central jejunum	57.2 ± 2.4^d	45.3 ± 8.6	a	153
Ileum	78.5 ± 10.5	52.3 ± 8.5	ab	254
Cecum	89.0 ± 7.7	80.2 ± 8.1	d	303
Descending colon	67.3 ± 3.9	68.4 ± 5.2	bc	247
Duodenum	51.8 ± 6.4	53.2 ± 11.2	ab	96
Proximal jejunum	55.6 ± 7.0	58.0 ± 5.2	abc	166
Central jejunum	57.4 ± 8.4	46.2 ± 8.2	a	156
Distal jejunum	46.6 ± 10.7	52.6 ± 6.3	a	181
Ileum	60.6 ± 13.6	54.8 ± 8.5	abc	142
Cecum	79.6 ± 10.7	79.4 ± 12.1	d	216
Spiral colon	57.6 ± 7.3	67.4 ± 17.9	abcd	195
Descending colon	60.6 ± 13.2	87.4 ± 6.9	cd	267
Rectum	62.8 ± 7.9	80.8 ± 10.4	bcd	236

^a All samples consisted of five replicate cattle per treatment, with the exception of digesta from the central jejunum of treatment cattle (n = 3), from the ileum of control and AS700 treatment cattle (n = 3), and from the cecum and descending colon of AS700 treated cattle (n = 4).
^b Within each sample type (i.e. digesta or mucosa), locations (averaged over treatment) not followed by the same letter differ (P ≤ 0.05) as determined by Fisher's least significant difference (LSD).
^c Total unique T-RFs (all animals combined by location and sample type).
^d Values represent the mean ± the standard error of the mean.

ISSN: 1757-4749