Hepatic Fatty Acid Composition in Periparturient Dairy Cows with Fatty Liver Induced by Intake of a High Energy Diet in the Dry Period

Abstract

The present study compared the hepatic fatty acid composition of cows that were fed a high energy diet during the dry period to induce fatty liver after parturition with that of control cows. Treated cows had higher concentrations of plasma nonesterified fatty acids as a result of greater lipolysis after parturition than did control cows; consequently, the treated cows accumulated greater amounts of triacylglycerols in the liver. Before parturition, treated cows had lower percentages of oleic acid and higher percentages of linoleic acid than did control cows, but percentages of other fatty acids were similar for both groups. After parturition, percentages of each fatty acid were changed substantially, particularly the four major fatty acids (palmitic, stearic, oleic, and linoleic acids). For treated cows, the percentages of palmitic and oleic acids were higher at 0.5 wk after parturition than at 1 wk before parturition; percentages of stearic and linoleic acids decreased. Unlike treated cows, the percentages of both oleic and linoleic acids in the control cows did not change during that time. Moreover, we found that when lipolysis decreased, as indicated by lower plasma nonesterified fatty acid concentrations, the percentages of each fatty acid gradually rebounded toward the concentrations measured before parturition; this observation indicates that the shift in hepatic fatty acid composition is influenced by lipolysis. The increased lipolysis after parturition led to a vast increase in the hepatic triacyglycerol concentration and to a shift in hepatic fatty acid composition.

Fatty Acid Profiles in Relation to Triglyceride Level in the Liver of Dairy Cows

“…Accumulation of palmitic acid in fatty liver in the present study seemed to coincide with weakened elongation of palmitic acid to stearic acid, however, the elongation activity is particularly weak in bovine liver [2]. In line with Rukkwamsuk et al [7,8], owing to the measurement of fatty acids from whole lipids of the liver, interpretation is confounded in the present study by the different fates of fatty acids in the presence in TG and those in phospholipids [3]. Under physiological circumstances, a strategic functional role of unsaturated fatty acids might be to regulate lipid fluidity because, by chemical nature, they preclude excessive accumulation of high melting temperature, or hard lipids.…”

“…In cattle, much information is available on the fatty acid proportions in soft tissue such as muscle and adipose tissue [12]. Little is available, however, on the fatty acid profiles and metabolic behavior of the individual fatty acids in the liver, particularly in dairy cows with fatty liver [7,8]. The purpose of the present study was to evaluate the proportions of the various fatty acids in the liver, especially in cows with increased hepatic TG.…”

Effects of continuous lactation and short dry periods on mammary function and animal health

“…This stress can be minimized by feeding a single diet during the entire dry period. There are three scenarios for feeding a single diet during the nonlactating period; (i) a moderateenergy diet can be delivered for an 8 week dry period; however, in this case, cows may be over-conditioned and show higher incidence of metabolic disorders (Rukkwamsuk et al, 1999). (ii) The second scenario is to deliver a lowenergy diet throughout the dry period.…”

Effect of various dietary fat supplementations on liver lipid and glycogen of high-yielding dairy cows in the peripartal period

“…Based on our experience and on the results of other authors, significant lipid accumulation (Rukkwamsuk et al, 1999) and glycogen depletion (VazquezAnon et al, 1994) can be detected in the liver of high-yielding cows in the peripartal period. Our results provide a similar picture of the lipid content in the liver of cows with increased body condition (Van den Top et al, 1996) or with high milk production (Andersen et al, 2005), which are especially energy sensitive in the period around calving (Bines, 1976).…”