Dietary n-3 fatty acids influence yolk fatty acid deposition and laying hen liver physiology /
Menhaden oil (MO) is commonly used as a n-3 fatty acid (FA)
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| Format: | Thesis Book |
| Language: | English |
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[Place of publication not identified] :
[publisher not identified] ;
1997.
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| Subjects: | |
| Online Access: | http://proxy.library.tamu.edu/login?url=http://proquest.umi.com/pqdweb?did=736824011&sid=1&Fmt=2&clientId=2945&RQT=309&VName=PQD |
| Summary: | Menhaden oil (MO) is commonly used as a n-3 fatty acid (FA) rich feed ingredient for the production of enriched shell eggs. However, previous studies indicate that dietary MO results in enhanced liver lipid accumulation in laying hens. This consequence may offset the nutritional benefits of dietary MO. The purpose of the current study was to investigate marine microalgae (MA) as an alternative n-3 FA rich feed ingredient for enriched shell egg production. The influence of graded levels of dietary MA on yolk n-3 FA deposition, egg production parameters and sensory characteristics of enriched eggs were determined. Additionally, MO and MA were compared for the influence of these n-3 FA rich feed ingredients on liver fatty acids, liver total lipid content and liver fatty acid binding protein (L-FABP) expression. Liver lipid classes were determined in hens with spontaneous fatty liver syndrome (FLS) to elucidate how fatty acids may contribute to FLS in laying hens. Dietary MA promoted the efficient deposition of yolk n-3 FA when fed at a level of 2.4% without influencing egg production parameters. Additionally, panelists found eggs from hens fed up to 4.8% MA as acceptable in flavor. Liver and yolk FA profiles of eggs from hens fed MO, containing both eicosapentaenoic acid and docosahexaenoic acid, indicated that while docosahexaenoic acid was readily enriched in liver and yolk, eicosapentaenoic acid did not accumulate in either of these sites. In control fed hens, fatty (CF) and non-fatty (CNF) livers were compared, L-FABP expression was enhanced in CF livers. Furthermore, the cholesterol ester fraction of CF livers contained more linoleic acid than CNF livers. The L-FABP expression was also enhanced by MO-induced hepatic lipidosis when compared to hens with spontaneous hepatic lipidosis. The hepatic lipid distribution of hens fed n-3 FA as MA remains to be determined. In conclusion, MA is a useful n-3 FA feed ingredient for the production of enriched shell eggs that are acceptable to consumers. Liver fatty acid binding protein expression is responsive to hepatic lipidosis whether or not lipid accumulation is initiated by dietary n-3 FA. |
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| Item Description: | Vita. "Major Subject: Nutrition". In title, numerals are used. |
| Physical Description: | x, 100 leaves ; 28 cm. Issued also on microfiche from University Microfilms Inc. |
| Bibliography: | Includes bibliographical references: pages 88-96. |