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Abstract

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.

Changes of Plasma Fatty Acids in Four Lipid Classes to Understand Energy Metabolism at Different Levels of Non-Esterified Fatty Acid (NEFA) in Dairy Cows

“…Studies in human and veterinary medicine showed how liver diseases and fatty infiltration into the hepatocytes reduce the secretion and activity of the enzyme. A reduced activity of LCAT therefore results in a decrease of plasma CE [ 44 , 45 ]. In serum of dairy cows, LCAT activity decrease after calving due to excessive hepatic deposition of triglycerides that damage liver function [ 46 ].…”

“…In the study of Battista et al, dairy cows with liver lipidosis (53.77 ± 43.69 mg/dL) had lower CE concentrations than animals without fatty infiltration (63.06 ± 27.38 mg/dL) [ 47 ]. Therefore, ketotic cows reduced blood CE and LCAT concentration compared to healthy cows [ 36 , 45 ].…”

“…Ketotic cows with elevated BHB and NEFA have a plasmatic concentration of PL lower than healthy cows [ 45 ]. Yamdagni and Schultz showed that in HK dairy cows, the values of PL decreased by 38% [ 34 ].…”

Ketosis and its role in Bos taurus reproductive impairment

“…Нехватка стероидных гормонов в свою очередь может быть объяснена тем, что у молочных животных после родов происходит снижение концентрации эфиров холестерина, вызываемое снижением синтеза лецитинхолестеринацилтрансфераза (ЛХАТ) -фермента печени, превращающего свободный холестерин липопротеинов высокой плотности в эфиры холестерина (более гидрофобную форму холестерина) [35]. Холестерин является предшественником синтеза стероидных гормонов.…”

“…Холестерин является предшественником синтеза стероидных гормонов. По данным Накагавы и Като [35], концентрация ЛХАТ снижается до и сразу после отела, а также в период ОЭБ при кетозных заболеваниях. В исследованиях Фьоре и др.…”