Veterinary Medicine International

Research Article

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	6.01^a	6.56^b	6.36^b	0.0001	0.18	0.54
SE	0.17	0.20^a	0.15^b	0.16^b	0.0241	0.036	0.3
24-h minimum pH	5.91	5.58^a	6.21^b	5.95^b	0.0001	0.2	0.58
t < pH 6.3 (min/d)	602	1126^a	97^b	583^c	0.001	323.99	0.6
t < pH 6.0 (min/d)	241	621^a	12^b	91^b	0.0003	241.75	0.54
t < pH 5.8 (min/d)	125	347^a	0^b	26^b	0.0051	188.83	0.4
t < pH 5.5 (min/d)	35	101^a	0^b	3^b	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.