Research Article

Continuous and Long-Term Measurement of Reticuloruminal pH in Grazing Dairy Cows by an Indwelling and Wireless Data Transmitting Unit

Table 1

Mean reticuloruminal pH during feed changeover (phases 1–7), feed intake, and nutrient contents.

MeanPhasesP-valueSEM1
Phase 1Phase 2Phase 3Phase 4Phase 5Phase 6Phase 7

Mean pH value6.436.58a6.54ab6.49ab6.46ab6.40abc 6.34bc6.19c0.0060.1568.98
SEM10.190.15a0.17a0.24b0.21ab0.19ab0.18ab0.19ab0.5020.0729.95
24-h minimum pH6.016.236.195.935.996.005.935.750.0540.20256.89
t < pH 6.3 (min/d)4912583214174484366758840.05330856.89
t < pH 6.0 (min/d)896a6a148a71ab55ab68ab261b0.226165.9843.62
t < pH 5.8 (min/d)280a0a53b23ab10ab11ab96b0.68897.629.89
t < pH 5.5 (min/d)20a0a1a5a0a0a6a0.8488.2823.74

Feed intake
 Hay (kg DM/d)3.63.93.73.73.73.73.72.700.0999.14
 Grass Silage (kg DM/d)3.77.83.64.13.13.73.6001.6081.74
 Concentrate (g/kg DM)1.82.81.81.81.81.81.81.300.0898.26
 Pasture (g/kg DM)9.7010.19.911.010.310.615.901.4695.1
 Daily DMI (kg DM)18.814.419.219.519.619.519.619.900.7794.75

Nutrient contents
 Crude protein (g/kg DM)14713315014614814714615801.3398.39
 Fiber (g/kg DM)21124021021220620920818807.4291.96
 Energy (MJ NEL/kg)6.415.996.446.416.486.436.446.6700.0992.58
 NDF (g/kg DM)4144544054154074134163910.1308.5593.08
 ADF (g/kg DM)234275231235227232231208010.1291.31
 ADL (g/kg DM)303429302930302700.7295.98

a–cLeast squares means within a row without a common superscript differ significantly ( ).
1SE of least squares means.