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Regulation of milk fat synthesis through either direct administration or endogenous production of conjugated linoleic acid
Citation
Hanson, Travis William.. (2008). Regulation of milk fat synthesis through either direct administration or endogenous production of conjugated linoleic acid. Theses and Dissertations Collection, University of Idaho Library Digital Collections. https://www.lib.uidaho.edu/digital/etd/items/etd_94.html
- Title:
- Regulation of milk fat synthesis through either direct administration or endogenous production of conjugated linoleic acid
- Author:
- Hanson, Travis William.
- Date:
- 2008
- Keywords:
- Milkfat--Synthesis--Regulation Linoleic acid--Synthesis Dairying
- Program:
- Animal Physiology
- Abstract:
- Conjugated linoleic acid exhibits multiple health benefits to humans, and is present in products from ruminant animals including milk. Commercially available mixtures of CLA isomers have elicited milk fat depression in lactating animals. These mixtures of CLA isomers area in a free fatty acids (FFA) form whereas naturally occurring fats are typically triglycerides (TG). In the first study of this dissertation, lactating cows were abomasaly infused either FFA or TG forms of mixtures of CLA isomers. Both treatments elicited milk fat depression similarly (P<0.05). Furthermore reduced short chain fatty acids show decreased de novo fatty acid synthesis within the mammary gland for both treatments. No detected change in milk yield or other milk components was detected between treatments.;Secondly, in order to determine a viable way to administer CLA while protecting it from biohydrogenation within the rumen, cows were fed either supplements containing calcium salts of CLA (CaCLA) or calcium salts of palm fatty acids (CaPalm). CaCLA resulted in reduced (P.0.05) milk fat concentrations. Fatty acids analysis revealed reductions in de novo fatty acids indicating direct inhibition of fat synthesis within the mammary gland during CaCLA. No difference (P.0.05) was detected in milk yield, feed intake or other milk components. These findings support CaCLA as a viable way to administer CLA while avoiding biohydrogenation within the rumen.;Thirdly, either linoleic acid or oleic acid was administered via rumen cannula during the feeding of a low forage diet to reduce rumen pH. Findings were consistent with our hypothesis that milk fat depression would occur during linoleic acid administration yet not oleic supplementation. Lower rumen pH is associated with alterations in biohydrogenation pathways with the rumen which produce trans-10, cis-12 CLA as an intermediate. All three of the studies presented in this dissertation resulted in increased concentrations of trans -10, cis -12 CLA in the milk. Furthermore, these studies also all revealed reduction in de novo fatty acid synthesis within the mammary gland. These finding are in agreement with others whom have observed trans-10, cis-12 CLA to be associated with milk fat depression via direct inhibition of fatty acids within the mammary gland.
- Description:
- Thesis (Ph. D., Animal Physiology)--University of Idaho, April 2008.
- Major Professor:
- Mark A. McGuire.
- Defense Date:
- April 2008.
- Type:
- Text
- Format Original:
- xii, 116 leaves :ill. ;29 cm.
- Format:
- record
Rights
- Rights:
- In Copyright - Educational Use Permitted. For more information, please contact University of Idaho Library Special Collections and Archives Department at libspec@uidaho.edu.
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