Table 3.

Experiment B: Megasphaera elsdenii colonization of inoculated and uninoculated newborn pigs^a

Day after birth	Day from weaning	M. elsdenii fecal population in pig groupb
		Inoculated with M. elsdenii			Uninoculated (control)
		Range (5 pigs)	Avg (total no. of pigs)	SD	Range (4 pigs)	Avg (total no. of pigs)	SD
10	−10	<LOD to 6.6 × 105	3 × 105 (3)	3.3 × 105	<LOD to 8.3 × 104	8 × 104 (1)	NA
18	−2	<LOD to 1.4 × 106	7 × 105 (3)	6.6 × 105	<LOD	Und (4)	NA
31	11	1 × 107 to 6 × 107	3.3 × 107 (5)	2.3 × 107	8 × 106 to 1.6 × 107	107 (4)	4.6 × 106
45	25	6 × 107 to 1.8 × 108	2.3 × 108 (5)	1.6 × 108	2.4 × 107 to 1 × 108	6.5 × 107 (4)	4.5 × 107
73	53	2.6 × 106 to 2 × 107	9.5 × 106 (5)	7.3 × 106	2.6 × 106 to 1 × 108	3.1 × 107 (4)	5.1 × 107

^aOf nine littermate pigs, five were inoculated with M. elsdenii antibiotic-sensitive strains and four control pigs were given sterile medium at various times after birth (Fig. 1). Pigs were weaned at 20 days of age.

^bCFU/g (wet weight) of feces, as determined by plating dilutions of fecal suspensions onto Me109M agar medium. SD, sample standard deviation for average fecal counts; Und, not detected; <LOD, beneath the limit of detection, defined in Table 1; NA, not applicable, insufficient sample.