Reduced activity of lecithin:cholesterol acyltransferase in the serum of cows with ketosis and left displacement of the abomasum.

Lecithin:cholesterol acyltransferase (LCAT) activity was evaluated in sera from cows with ketosis and in some with left displacement of the abomasum (LDA) that occurred during early lactation. The enzyme activities of 652 +/- 214 U (mean +/- SD) in cows with ketosis (n = 6) and 683 +/- 110 U in those with LDA (n = 5) were significantly (p < 0.01) decreased compared to those in healthy normal cows (994 +/- 65 U, n = 8). Serum concentrations of free cholesterol, cholesteryl esters (CE) and phospholipids were similarly decreased in the two diseases. Cows whose LCAT activity and CE concentration were lower than the normal values were detected while in the non-lactating stage, and some of these cows had ketosis after parturition. It is suggested that evaluation of the LCAT activity and of the CE concentration during the non-lactating stage would be useful in detecting cows that are susceptible to postparturient disorders such as ketosis.