Changes in blood values of glucose, insulin and inorganic phosphorus in healthy and ketotic dairy cows after intravenous infusion of propionate solution

The aim of the present study was to determine the degree of blood glucose utilization by peripheral tissue on the basis of changes in blood concentrations of glucose, insulin and inorganic phosphorus in healthy (n = 10) and ketotic cows (n = 10) after intravenous infusion of propionate solution. Blood samples were taken in both groups of examined cows at the following time intervals: just before (time 0) and 8, 30, 60, 120, 180, 240 and 480 min after the intravenous infusion of 1.84 mol-l(-1) solution of propionate in the amount of 1ml center dot kg(-1) of body weight. Glucose and insulin blood serum values in both groups of cows increased significantly within 120 min of the experiment (p < 0.05). Significantly lower values (p < 0.05) of glucose in blood of ketotic cows, compared to the blood value of glucose in healthy cows were established within 30, 60, 120 and 240 min of the experiment, as a consequence of the decreased gluconeogenic ability of the liver in the ketotic cows. Significantly lower values (p < 0.05) of insulin in blood of ketotic cows in comparison with healthy ones were established within 240 and 480 min of the test. That indicates that the ability of beta cells of the endocrine pancreas to release insulin is reduced in cows suffering from ketosis. After intravenous administration of propionate, it was established that values of inorganic phosphorus were reduced in blood in both groups of cows after 8, 30, 60, 120 240 and 480 min. Within 480 min of the test there was a significant decrease (p < 0.05) in blood value of inorganic phosphorus in ketotic cows in comparison with healthy ones. This is linked with the active entry of glucose into glucolytic pathway of peripheral tissues. It can thus be concluded that there is a higher degree of blood glucose utilization by peripheral tissues in ketotic cows.