Plasma transport and mammary uptake of trans fatty acids in dairy cows

Vargas Bello Pérez, Einar (2011) Plasma transport and mammary uptake of trans fatty acids in dairy cows. PhD thesis, University of Nottingham.

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In this thesis, aspects of metabolism of lipids in dairy cows were studied, particularly 18:1 trans fatty acid (tFA) concentrations in plasma and lipoprotein fractions, and transportation of FA in epithelial mammary gland cell cultures.

Two in vivo studies were conducted to elucidate which lipoprotein fractions were involved in bovine plasma transport of tFA by infusing oils that induced different plasma tFA profiles. Fatty acid profiles of plasma and lipoprotein fractions [high (HDL), low (LDL), and very low density (VLDL) lipoprotein fractions] were analysed. Results showed that VLDL fraction was the main transport mechanism of tFA in plasma and was more responsive to supply of tFA.

MAC-T cell cultures were used to study specific aspects of lipid uptake without interference from the cow’s digestive system and general metabolism. Treatments consisted of adding long-chain FA solutions to lactogenic medium at varying concentrations. After incubation, cystosolic triacylglycerol (TAG), protein and DNA contents were determined. Results demonstrated that cytosolic TAG accumulation is stimulated by addition of long-chain FA, which affects FA profile of cytosolic free FA.

Overall, results from this thesis enhance knowledge on plasma transport and mammary uptake of 18:1 tFA in dairy cows. The information strengthens understanding of some aspects of milk fat synthesis and metabolism of FA in dairy cows fed with different sources of tFA. Findings from this thesis are important because saturated FA and tFA in milk fat have caused concern among human health researchers and more recently milk fat has gained appreciation as a functional food due to the health-promoting potential of some FA (vaccenic and conjugated linoleic acids) found specifically in ruminant-derived products.

Item Type: Thesis (University of Nottingham only) (PhD)
Supervisors: Garnsworthy, P.C.
Salter, A.M.
Subjects: Q Science > QP Physiology > QP501 Animal biochemistry
Faculties/Schools: UK Campuses > Faculty of Science > School of Biosciences
Item ID: 12179
Depositing User: EP, Services
Date Deposited: 26 Apr 2012 09:52
Last Modified: 15 Dec 2017 12:30

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