TABLE 2.

Fecal shedding of E. coli O157:H7 by calves during period 2 of the experiment^a

Group and calf no.	E. coli O157:H7 count (log10 CFU/g) at dayb:
	1	4	7	10	13
Group 1
74	−	1.0	+	−	−
76	2.2	2.1	1.5	1.5	1.3
78	1.6	+	+	1.0	+
79	2.7	3.3	2.5	+	−
80	4.1	2.6	1.8	3.8	3.8
83	3.8	4.7	3.0	2.3	1.5
Avg	2.4	2.3	1.6	1.5	1.1
SD	1.5	1.6	1.1	1.4	1.5
Group 2
73	5.1	4.0	4.3	2.9	3.0
75	1.0	+	1.5	1.0	−
77	1.0	+	−	1.5	2.2
81	1.0	1.0	+	+	+
82	+	1.6	1.6	1.0	−
84	4.1	5.2	2.9	−	1.0
85	2.0	4.1	6.0	2.0	−
86	3.8	6.5	4.8	3.4	3.6
Avg	2.3	2.9	2.7	1.5	1.3
SD	1.8	2.4	2.2	1.2	1.5

^aThe diets of group 1 calves were supplemented with 10⁸ CFU of the eight colicinogenic E. coli strains per g.

^b+, detected only by enrichment and assigned an arbitrary value of 0.3 log₁₀ CFU/g for calculation of averages; −, assigned a value of 0 log₁₀ CFU/g for calculation of averages.