Continuous and Long-Term Measurement of Reticuloruminal pH in Grazing Dairy Cows by an Indwelling and Wireless Data Transmitting Unit
Table 2
Effects of different dietary treatments (GC, GH, and G) on reticuloruminal pH, standard deviation, mean of daily minimum (nadir), and the time (min/d) pH were below 6.3, 6.0, 5.8, and 5.5.
Mean
Treatments
Statistics
1
2
3
GC
GH
G
P value
SEM1
Mean pH value
6.31
6.01a
6.56b
6.36b
0.0001
0.18
0.54
SE
0.17
0.20a
0.15b
0.16b
0.0241
0.036
0.3
24-h minimum pH
5.91
5.58a
6.21b
5.95b
0.0001
0.2
0.58
t < pH 6.3 (min/d)
602
1126a
97b
583c
0.001
323.99
0.6
t < pH 6.0 (min/d)
241
621a
12b
91b
0.0003
241.75
0.54
t < pH 5.8 (min/d)
125
347a
0b
26b
0.0051
188.83
0.4
t < pH 5.5 (min/d)
35
101a
0b
3b
0.0021
51.3
0.44
Feed intake
Hay (kg DM/d)
2.0
1.0
1.0
4.0
0
0.61
0.76
Concentrate (kg DM/d)
2.0
4
1.75
0
0
0.66
0.88
Pasture (kg DM/d)
16.3
15.5
16.7
16.8
0.0432
0.86
0.34
Daily DMI (kg DM/d)
20.2
20.7
19.7
20.1
0.0033
0.45
0.53
Nutrient values
Crude protein (g/kg DM)
168
163
168
172
0
1.94
0.8
Fiber (g/kg DM)
183
165
180
204
0
4.85
0.93
Energy (MJ NEL/kg)
6.68
6.83
6.73
6.48
0
0.06
0.89
NDF (g/kg DM)
385
359
379
416
0
7.16
0.93
ADF (g/kg DM)
206
184
201
234
0
6.22
0.93
ADL (g/kg DM)
27
24
26
29
0
0.66
0.91
a–cLeast squares means within a row without a common superscript differ significantly (P < 0.05).
1SE of least squares means.