Effect of dietary
phospholipid on essential fatty acid requirements and tissue lipid
composition of Litopenaeus vannamei juveniles
M.L. González-Félix, D.M. Gatlin III, A.L.
Lawrence, M. Perez-Velazquez-2002
Aquaculture, 207(1-2): 151-167
Abstract:
A 6-week study was conducted to evaluate the effect
of dietary phospholipids (PL) on essential fatty acid requirements of
juvenile Litopenaeus vannamei and their potential interaction. A 3×3
factorial experiment was carried out with increasing levels of soybean
lecithin as the dietary PL (0%, 1.5% or 3% of diet). Three dietary levels
(0%, 0.25% or 0.5% of diet) of docosahexaenoic acid (22:6n-3, DHA),
or an n-3 highly unsaturated fatty acid (HUFA) mixture containing 416
mg eicosapentaenoic acid (EPA)/g and 237 mg DHA/g were tested. No
significant interactions between the effects of PL and DHA or n-3
HUFA on growth were detected under these experimental conditions; however,
instantaneous growth rate (IGR) of shrimp was enhanced by addition of either
DHA or n-3 HUFA at 0.25% of diet. A higher dietary inclusion level
(0.5% of diet) did not further improve growth, and appeared to have a
detrimental effect on survival of shrimp. Also, an inclusion level of 3%
dietary PL significantly improved IGR of shrimp, and did not show a
significant effect on survival. PL supplementation did not consistently
increase the proportion of phosphatidylcholine or other PL in shrimp muscle.
The proportion of linoleic acid decreased as dietary DHA or n-3 HUFA
increased. Thus, these results corroborate the beneficial effects of dietary
PL on growth of shrimp, as well as their requirement for DHA and n-3
HUFA to achieve maximum growth.