|Influence of astaxanthin on growth rate, condition, and some blood indices of rainbow trout, Oncorhynchus mykiss|
Řehulka, J. (2000). Influence of astaxanthin on growth rate, condition, and some blood indices of rainbow trout, Oncorhynchus mykiss. Aquaculture 190: 27-47
In: Aquaculture. Elsevier: Amsterdam; London; New York; Oxford; Tokyo. ISSN 0044-8486, more
A trial was conducted in flow-through fibre-glass tanks at a water temperature of 11.1±3.0°C, at a dissolved oxygen content of 9.3±1.0 mg/l, and at an oxygen saturation level of 84.2±4.9% (mean±SD) in rainbow trout with average starting weight of 178±23 g for the effect of astaxanthin on growth, condition, and some hematological and blood biochemical indices of the fish. Using correlation and regression analysis methods, it was found that the fish fed a diet containing 49.8 mg astaxanthin/kg for 84 days had similar growth (the relative gain was 19.4 vs. 18.4%) and significantly (P<0.05) lower red blood cell count (RBC: 1.06 vs. 1.15 T/l), hematocrit (PCV: 0.386 vs. 0.422), hemoglobin (Hb: 71.8 vs. 76.5 g/l) and mean cell hemoglobin concentration (MCHC: 0.19 vs. 0.18) when compared to fish fed a diet without astaxanthin supplement. The fish fed the astaxanthin-containing diet had lower (P<0.05) plasma triacylglycerol (TGL: 3.69 vs. 4.85 mmol/l), lower (P<0.01) plasma calcium (Ca2+: 2.75 vs. 2.92 mmol/l) and significant (P<0.01) negative correlation between the levels of plasma cholesterol and plasma uric acid (r=-0.960 vs. r=-0.489). These changes in blood remained within the interval of physiological values on our laboratory's summation curve for rainbow trout under Czech conditions. The different relationships between some biochemical indices (lactate dehydrogenase and cholesterol) and the parameters of the oxygen in water (quantity of dissolved oxygen and the oxygen saturation of water), and/or the water temperature, are discussed.