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The influence of dietary fatty acids on tissue lipid composition in rainbow trout (Salmo gairdneri)

The effects of different dietary lipids on the growth, nutrition
and tissue lipid profiles of rainbow trout raised to market size on a
commercially available ration were examined. Rainbow trout of 80 g
mean initial weight were fed pellets prepared according to Oregon
Moist Pellet specifications for 20 weeks. Salmon oil (0MP-1),
soybean oil (OMP-2), linseed oil (OMP-3), chicken fat (OMP-4), pork
lard (OMP-5) and beef tallow (OMP-6) were used for the 6% lipid
component of the diets. No differences in feed conversion or growth
rate were observed across diet groups.
Trout nutrition was monitored by three blood parameters -- red
blood cell (RBC) fragility (hemolysis), packed cell volume (PCV)
(hematocrit), and percent hemoglobin. The OMP-1 diet appeared to
have caused oxidative stress in trout as measured by hemolysis, while
hematocrit and percent hemoglobin values were uniform across diet
groups.
Tissue levels of total n-3 fatty acids were highest in the OMP-3
group and decreased in the order OMP-1 > OMP-2 = OMP-4 = OMP-5 =
OMP-6. However, unaltered linolenic acid (18:3 n-3) comprised almost
50% of the n-3 fatty acid content of OMP-3 trout tissue lipid. The
level of total 20:5 n-3 plus 22:6 n-3 (18%), was 33% higher in tissue
from OMP-1 trout than tissue from all other diet groups which held
fairly constant at 12% across OMP groups 3-6. The lowest tissue
level of total 20:5 n-3 plus 22:6 n-3 was found in the OMP-2 trout,
10%.
Trout raised on the OMP-1 diet also retained higher tissue stores
of 20 and 22 carbon monoenes than trout fed OMP diets 2-6, but less
than dietary levels. In contrast, trout fed OMP diets 2-6 retained
higher tissue levels of these same fatty acids than dietary levels.
The diet ratio of polyunsaturated fatty acids (PUFA)/22:1 appeared to
influence whether 22:1 was conserved or oxidized.
The most favorable balance of trout tissue monoenes, n-6 fatty
acids and total 20:5 n-3 plus 22:6 n-6 for human health was found in
trout fed the OMP-6 diet. / Graduation date: 1988

Identiferoai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/27145
Date31 August 1987
CreatorsGreene, Diana H.
ContributorsSelivonchick, D. P.
Source SetsOregon State University
Languageen_US
Detected LanguageEnglish
TypeThesis/Dissertation

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