TABLE 2.

Effect of treatment on richness and alpha diversity at 97% similarity after rarefaction to 3,484 sequences per sample for samples collected 4 weeks after weaning.

	Treatment1
Item	CON	PCON	ENZ	SE	P-value
Shannon index	9.8	9.8	9.7	0.09	0.58
Simpson index	0.9973	0.9974	0.9972	0.00	0.81
Chao1	4,316	4,239	4,108	158.00	0.45
PD whole tree2	104.3	103.5	100.7	2.09	0.23
Observed OTUs	1,592	1,609	1,555	45.30	0.50

¹CON = conventional cow-calf system without supplementation of calves. PCON = calves were creep fed. ENZ = calves were creep fed with an enhanced feed containing xylanase; ²Faith’s Phylogenetic Diversity. None of the means within each row were significantly different (P ≥ 0.05) according to Fisher’s Least Significant Difference method.