Table 7. Effect of feeding Se-biofortified hay in a 9-week preconditioning period on the presence, and number of calves harboring per Control (C) and High-Se (Se) treatment groups, of the minor nasal microbiota phyla^*.

	Week 0		Week 9		Week 12		P values
Phylum	C	Se	C	Se	C	Se	Wk 0	Wk 9	Wk 12
	(n = 15)	(n = 15)	(n = 15)	(n = 15)	(n = 15)	(n = 15)
Acidobacteria	13	12	0	7	2	3	1	0.002	1
Chlamydiae	0	0	0	9	0	3	1	0.0007	0.22
Chloroflexi	15	13	10	13	15	15	0.48	0.39	1
Elusimicrobia	2	1	11	14	7	8	1	0.33	1
Fibrobacteres	11	8	9	12	12	13	0.45	0.43	1
Fusobacteria	2	2	6	10	14	14	1	0.27	1
GN02	9	6	9	10	12	11	0.17	1	1
Gemmatimonadetes	10	11	1	8	12	9	1	0.01	0.43
Lentisphaerae	4	9	15	15	14	12	0.14	1	0.60
OP11	0	1	0	8	0	0	1	0.002	1
Planctomycetes	12	11	6	11	10	11	1	0.14	1
Spirochaetes	12	8	14	15	15	15	0.25	1	1
TM7	0	0	0	11	0	6	1	<0.0001	0.02
WPS-2	0	1	0	9	0	1	1	0.0007	1
Thermi	10	9	14	15	15	15	1	1	1
Other Bacteria	1	0	2	12	13	13	1	0.0007	1

*Phyla that were observed in 13 calves or fewer of Control and High-Se calves throughout the production stages (week 0 = weaning; week 9 = end of Se supplementation preconditioning period; week 12 = feedlot period) are presented as number of calves where phyla are present. Fisher’s Exact test was used to compare treatment groups at each time (0, 9, and 12 weeks).