Turkish Journal of Fisheries and Aquatic Sciences
2014, Vol 14, Num, 4 (Pages: 853-862)
Dietary Isoleucine Influences Non-Specific Immune Response in Juvenile Olive Flounder (Paralichthys olivaceus)
Samad Rahimnejad 1 ,Kyeong-Jun Lee 1
1 Jeju National University, Department of Marine Life Sciences, Jeju, South Korea
DOI :
10.4194/1303-2712-v14_4_02
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A 9-week feeding trial was conducted in low temperature season to evaluate the effects of varying levels of dietary
isoleucine on hematology and innate immune response of juvenile olive flounder. Six isonitrogenous (45% crude protein) and
isocaloric (4.45 kcal g-1 gross energy) diets containing graded levels of isoleucine (0.48, 0.87, 1.43, 1.94, 2.37 and 2.78% dry
diet) were formulated. Triplicate groups of fish (8.59 ± 0.13 g) were fed the six test diets to apparent satiation twice daily.
Fish growth performance was affected by dietary isoleucine levels and the highest growth was obtained at 1.43% isoleucine.
The results showed the significant (P<0.05) increase of plasma total protein and cholesterol concentrations at isoleucine levels
of 1.43 - 2.37% compared to those offered 0.48% isoleucine. Also, significant reductions in plasma alanine aminotransferase
and aspartate aminotransferase activities were detected by increment of dietary isoleucine up to 1.94%. Fish innate immunity
was significantly affected by isoleucine levels. Significantly higher lysozyme activity was found at 0.87 - 2.37% isoleucine
and superoxide dismutase activity increased at 1.94-2.37% isoleucine levels. Respiratory burst activity and total
immunoglobulin level were significantly enhanced at isoleucine levels of 1.43-1.94 and 1.94%, respectively. The findings in
this study showed that inclusion of approximately 2% isoleucine in diets for olive flounder can enhance innate immunity. To
estimate isoleucine requirement of the species further studies are required.
Keywords :
Dietary isoleucine, olive flounder, Paralichthys olivaceus, growth, hematology, innate immunity