[Functional liver disorder in relation to decreased titratable acidity of milk]

The internal environment of 17 dairy cows was observed by help of 23 variables of metabolic profile in blood and milk at lowered titratable acidity of milk (Tab. I) Average values of the observed variables were compared with reference values in a histogramme (Fig. 1). We calculated the statistical significance of differences of arithmetical means from reference average. Using correlation analysis we calculated the correlation coefficients for the observed variables. We represented the chosen correlation relations in correlogrammes (Fig. 2). We found significant correlation relations between AST and titratable acidity (degrees SH) (r = 0.791), AST and milk pH (r 0.617), AST and lactose (r = 0.69), AST and glucose (r = -0.56), blood pH and milk pH (r = -0.608), milk pH and lactose (r = -0.89). Mutual relations of titratable acidity with chosen variables of blood serum and milk were evaluated by help of regression coefficients, calculated for each parameter from the mathematical model (Fig. 3). The nearest relations were found for blood pH (regression coefficient /k/ kPH = -11.9), for AST (kAST = -3.1), for milk pH (k milk pH = -1.72) and for Mg (k Mg = -1.98). We also compared the recorded results of titratable acidity with theoretical values of titratable acidity calculated from the mathematical model (Tab. II). The differences between them were not statistically significant. It is evident from the results that the acid-base balance and functional liver condition influence the titratable acidity of milk.