The metabolic activity of bovine adipocytes before and after parturition.

Adipocytes were isolated from biopsies of the subcutaneous adipose tissue of dairy cows before and after parturition. The diameter of the cells was measured and their lipogenic and lipolytic capacities were assessed by measurement of 14C-glucose incorporation and glycerol release. The concentration of non-esterified fatty acids (NEFA) in plasma at the time of biopsy was also measured. In the post calving samples, lipogenic activity of the adipocytes was reduced to a third of the precalving level, and oxidation of glucose to carbon dioxide almost ceased. Lipolytic activity increased five-fold after calving, and this was associated with an increase in plasma NEFA concentrations.