|
Calf age
|
P value
|
---|
1 week
|
3 weeks
|
6 weeks
|
---|
Active rumen bacteria
|
R. flavefaciens1
|
3.8 ± 1.9E08a
|
1.6 ± 0.4E09b
|
1.3 ± 0.5E09b
|
0.03
|
R. albus
|
1.4 ± 0.5E05
|
6.3 ± 6.2E06
|
2.2 ± 1.7E07
|
0.34
|
P. ruminicola
|
6.4 ± 2.7E04
|
4.4 ± 3.0E05
|
7.6 ± 7.4E07
|
0.37
|
E. ruminantium
|
7.8 ± 3.8E05
|
1.5 ± 0.6E06
|
1.6 ± 0.6E06
|
0.48
|
Rumen papillae
|
Length (μm)
|
317.8 ± 7.6a
|
413.0 ± 13.6b
|
678.1 ± 41.1c
|
< 0.01
|
Width (μm)
|
155.5 ± 2.7a
|
224.0 ± 6.3b
|
275.8 ± 9.0c
|
< 0.01
|
Rumen fermentation parameters
|
Acetate2
|
21.1 ± 2.2a
|
37.0 ± 2.8b
|
50.3 ± 3.8c
|
< 0.01
|
Propionate
|
10.6 ± 2.0a
|
25.8 ± 4.3b
|
36.3 ± 1.8c
|
< 0.01
|
Butyrate
|
5.6 ± 1.8a
|
11.8 ± 2.7b
|
17.8 ± 2.2b
|
< 0.01
|
Isobutyrate
|
0.3 ± 0.04a
|
0.8 ± 0.1b
|
1.3 ± 0.1c
|
< 0.01
|
Valerate
|
1.0 ± 0.4a
|
3.7 ± 0.7b
|
5.1 ± 0.8b
|
< 0.01
|
Isovalerate
|
0.3 ± 0.07a
|
0.8 ± 0.1a
|
1.3 ± 0.3b
|
< 0.01
|
Total
|
39.6 ± 6.2a
|
80.5 ± 9.0b
|
113.9 ± 6.9c
|
< 0.01
|
Acetate3
|
55.3 ± 2.7a
|
47.0 ± 2.4b
|
44.2 ± 1.9b
|
0.01
|
Propionate
|
26.7 ± 1.4
|
31.3 ± 2.9
|
32.1 ± 1.4
|
NS
|
Butyrate
|
13.0 ± 2.0
|
14.4 ± 2.5
|
15.4 ± 1.4
|
NS
|
Isobutyrate
|
0.8 ± 0.1
|
1.0 ± 0.1
|
1.2 ± 0.1
|
NS
|
Valerate
|
2.1 ± 0.5a
|
4.6 ± 0.6b
|
4.5 ± 0.6b
|
0.01
|
Isovalerate
|
0.8 ± 0.2
|
1.0 ± 0.2
|
1.2 ± 0.2
|
NS
|
- Means with different superscript letters within a row are significantly different at P < 0.05
- 1Density of active rumen bacteria (16S rRNA copy/g of rumen content)
- 2VFA concentration (mM/mL of rumen fluid)
- 3Molar proportion of VFA (%)