[Relationships between postpartum mobilization of body substances and rumen digestion in dairy cows]

Relationships between body tissue mobilisation during the postpartal period, and rumen fermentation were studied in 105 high yielding Holstein-Friesian dairy cows. A strongly positive correlation (p < 0.001) between the molar proportion of ruminal acetic acid, and a negative correlation (p < 0.001) between the molar percentage of ruminal propionic and butyric acid (on one hand), and body tissue mobilisation as well as blood plasma concentrations of free fatty acids, beta-hydroxybutyrate, and total bilirubin (on the other hand) were found. These results indicate that in animals with higher postpartal loss of body weight, ruminobacterial fermentation activity is lower, probably secondary to metabolic disturbances.