Ruminal pH, rumen temperature and concentrations of rumen NH3 N and VFA, and plasma urea N, as affected by feeding different N sources.
Dietary treatments
SEM
Control SBM U-Cal U-Cas
Ruminal pH 6.9 6.7 6.6 6.7 0.44
Ruminal temperature, °C 39.4 39.1 39.5 39.2 0.32
NH3-N, mg/dL 19.2a 15.4b 14.6b 14.5b 1.01
Plasma urea N, mg/dL 16.8a 13.2b 12.2b 12.7b 1.06
Total VFA, mM 114.5 115.3 115.4 119.2 8.55
VFA, mol/100 mol
Acetic acid (C2) 74.3 70.6 72.3 70.4 3.65
Propionic acid (C3) 18.9 21.5 19.5 22.3 4.11
Butyric acid (C4) 6.8 7.9 8.2 7.3 1.23
C2:C3 3.9 3.3 3.7 3.2 0.55
C2 + C4:C3 4.3 3.7 4.1 3.5 0.68