Decrease in stearic acid proportions in adipose tissues and liver lipids in fatty liver of dairy cows

Abstract

Samples of liver and perirenal, mesenteric and subcutaneous fat were collected from 16 sick necropsied dairy cows to evaluate the fatty acid profiles in the hepatic and adipose tissues associated with advanced fatty liver or hepatic lipidosis. Hepatic triglyceride and eight fatty acids were measured in the hepatic and adipose tissues. Six cows had more than 3% triglyceride on fresh weight in their livers and were classified as having fatty liver. Stearic and linoleic acid proportions in the liver decreased markedly with increased hepatic triglyceride levels, while the proportion of palmitic and oleic acids increased. The most striking fluctuations in hepatic lipidosis were manifested as decreased stearic acid in the adipose tissues including subcutaneous fat with the trend of decreasing stearic acid. Palmitic acid was elevated in hepatic and perirenal fat in fatty liver cows. In instances of advanced hepatic lipidosis, palmitoleic acid increased in only subcutaneous fat and not in perirenal or mesenteric fat. In addition to the proportions of hepatic fatty acids in fatty liver, this study also clarified the fluctuations observed in the profiles of fatty acids of the adipose tissues in cows with advanced hepatic lipidosis, particularly the decline in the proportions of stearic acid.

The fatty acid profile of subcutaneous and abdominal fat in dairy cows with left displacement of the abomasum

“…In general, the SUBC FA profile was in agreement with those reported in dairy (Rukkwamsuk et al, 2000;Sato and Inoue, 2006;Douglas et al, 2007;Zachut et al, 2010a) and in beef cattle (Eichhorn et al, 1986;Beaulieu et al, 2002;Oka et al, 2002;Siebert et al, 2003). Omental FA profiles are seldom reported in both dairy (Sato and Inoue, 2006) and beef cattle (Beaulieu et al, 2002) but seem consistent with perirenal FA profiles (dairy: Sato and Inoue, 2006;beef: Eichhorn et al, 1986;Beaulieu et al, 2002;Oka et al, 2002). In our study, the FA with the highest contribution to the ABD and SUBC FA was 18:1 cis-9, which is in agreement with previous dairy (Rukkwamsuk et al, 2000;Sato and Inoue, 2006;Douglas et al, 2007;Zachut et al, 2010a) and beef cattle studies (Eichhorn et al, 1986;Beaulieu et al, 2002;Oka et al, 2002;Siebert et al, 2003), although the concentrations mentioned in previous studies were higher (Figure 2).…”

“…As the data are limited in this research area, we compared our results for the individual FA (Figure 2) and the Δ 9 -desaturase indices (Figure 3) with data from both dairy and beef cattle. In general, the SUBC FA profile was in agreement with those reported in dairy (Rukkwamsuk et al, 2000;Sato and Inoue, 2006;Douglas et al, 2007;Zachut et al, 2010a) and in beef cattle (Eichhorn et al, 1986;Beaulieu et al, 2002;Oka et al, 2002;Siebert et al, 2003). Omental FA profiles are seldom reported in both dairy (Sato and Inoue, 2006) and beef cattle (Beaulieu et al, 2002) but seem consistent with perirenal FA profiles (dairy: Sato and Inoue, 2006;beef: Eichhorn et al, 1986;Beaulieu et al, 2002;Oka et al, 2002).…”

Hepatic pyruvate carboxylase expression differed prior to hyperketonemia onset in transition dairy cows

“…The major FA in adipose tissue are C16:0, C18:0, and C18:1 [8][9][10] and are expected to be increased in plasma postpartum as cows mobilize FA from adipose tissue, as was observed with increased postpartum plasma C16:0 and C18:1 relative to prepartum plasma in both HYK and nonHYK cows in the current study. Although both groups mobilized adipose tissue, the greater BCS loss and elevated NEFA of HYK cows would suggest that FA derived from adipose Expression of PC, PC: PCK1, and PC:PCK2 were log transformed for analysis to achieve normal residuals and thus are reported using the 67% confidence interval.…”

“…Prior work has demonstrated that subcutaneous adipose tissue FA profile does not change across the transition period [ 8 ], making it unlikely that preferential mobilization plays a major role in differential FA metabolism, at least within the subcutaneous depots. Relative to C16:0 and C18:1, C18:0 is present in lower proportions in subcutaneous fat, but at a greater proportion in internal fat stores [ 9 , 10 ] which are also mobilized during the peripartum period [ 32 ]. It is unknown if the difference in FA profiles and metabolic activity between adipose tissue depots [ 33 ] may impact the circulating FA profile or preferential mobilization and metabolism.…”

“…Although the general etiology of HYK has been described, the effects of HYK status on nutrient metabolism, specifically the potential for preferential FA use for hepatic fates, are not fully understood. The primary non-esterified fatty acid (NEFA) circulating in plasma during negative EB are C16:0, C18:0, and C18:1, which are derived from adipose tissue depots where they are stored [8][9][10]. Compared to cows restricted to maintenance energy intake prepartum, cows fed above maintenance requirements prepartum to induce fatty liver had increased blood NEFA and increased C16:0 and C18:1 in plasma and liver postpartum [8].…”