This study investigated the effects of abomasal infusion of essential fatty acids, especially alpha-linolenic acid, and conjugated linoleic acid on their distribution in milk fat and blood plasma and on the plasma inflammatory response in dairy cows from late to early lactation. The most important essential fatty acids for ruminants are alpha-linolenic acid and linoleic acid. They are abundant in pasture which is nowadays reduced in the ration of dairy cows due to the replacement of fresh feeds by preserved diets. Conjugated linoleic acid is formed as a by-product during ruminal biohydrogenation of essential fatty acids and has been associated with positive effects on the energy metabolism and immune system.
Forty rumen-cannulated Holstein Friesian cows were assigned to four treatment groups in their late second lactation. Prior to supplementation, cows were fed a total mixed rations with a low-fat content. In late gestation cows were abomasally treated with coconut oil, linseed and safflower oil, conjugated linoleic acid, or both. Performance data, milk composition and fatty acid pattern in milk and plasma as well as inflammatory response parameters in plasma were measured regularly. Furthermore, liver tissue was tested for the abundance of genes related to the inflammatory response.:TABLE OF CONTENTS
ABBREVIATIONS
1. INTRODUCTION
2. LITERATURE OVERVIEW
2.1 Essential Fatty Acids and Conjugated Linoleic Acid
2.1.1 Essential Fatty Acids (EFA)
2.1.2 Conjugated Linoleic Acid (CLA)
2.1.3 EFA in Dairy Cow Nutrition
2.2 Fatty Acid Distribution in Blood, Erythrocyte Membranes, and Milk Fat
2.2.1 Plasma Lipids
2.2.2 EFA and CLA in Plasma Lipids
2.2.3 EFA and CLA in Erythrocyte Membranes
2.2.4 EFA and CLA in Milk Fat
2.3 Effects of EFA and CLA on Inflammatory Processes during the Transition Period
2.3.1 Metabolic and Immunological Challenges during the Transition Period
2.3.2 Effects of EFA on the Metabolism, Inflammatory- and Immune Response
2.3.3 Effects of CLA on the Metabolism, Inflammatory- and Immune Response
2.4 Scope of the Thesis
3. PUBLICATION
4. GENERAL DISCUSSION
4.1 Abomasal Infusion
4.2 Animal Performance
4.3 Distribution of EFA and CLA in Blood and Milk Fat
4.4 Effects of EFA and CLA on Plasma and Hepatic Acute Phase and Inflammatory Response
4.5 Conclusion and Practical Considerations
4.5.1 Summary of EFA effects
4.5.2 Summary of CLA effects
4.5.3 Summary of synergistic effects of EFA and CLA
4.5.4 Summary of Observations apart from Treatments and Practical Considerations
5. SUMMARY
6. ZUSAMMENFASSUNG
7. REFERENCES
APPENDIX
| Identifer | oai:union.ndltd.org:DRESDEN/oai:qucosa:de:qucosa:87983 |
| Date | 13 November 2023 |
| Creators | Gnott, Martina |
| Contributors | Universität Leipzig |
| Source Sets | Hochschulschriftenserver (HSSS) der SLUB Dresden |
| Language | English |
| Detected Language | English |
| Type | info:eu-repo/semantics/acceptedVersion, doc-type:doctoralThesis, info:eu-repo/semantics/doctoralThesis, doc-type:Text |
| Rights | info:eu-repo/semantics/openAccess |
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