Effect of dietary encapsulated organic salts (Na‐acetate,Na‐butyrate,Na‐lactate and Na‐propionate) on growth performance,haemolymph, antioxidant and digestive enzyme activities and gut microbiota of juvenile narrow clawed crayfish,Astacus leptodactylus leptodactylus Eschscholtz, 1823 |
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| Authors: | Omid Safari Marina Paolucci Hamidreza Ahmadniaye Motlagh |
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| Abstract: | A 63‐day experiment was done to study the effects of four levels (5, 10, 20 and 50 g/kg) of encapsulated organic salts (Na‐acetate, Na‐butyrate, Na‐lactate and Na‐propionate) on the growth indices and haemato‐immunological responses of crayfish Astacus leptodactylus leptodactylus (4.38 ± 0.08 g). Crayfish were distributed at 51 1,000‐L tanks (17 treatments at triplicate). The highest values of final weight (27.86 g), specific growth rate (2.94% body weight per day) and survival rate (96%) were observed in the crayfish fed the 20 g/kg of encapsulated Na‐propionate diet (p < .05). The highest activities of phenoloxidase (7.4 U/min), superoxide dismutase (7.80 U/min) and lysozyme (9.40 U/min) were observed in the gut of crayfish fed the 20 g/kg of encapsulated Na‐propionate diet (p < .05), as well as the highest activities of alkaline protease (10.70 U/mg), lipase (9.10 U/mg), amylase (9.60 U/mg) and the lactobacillus count (p < .05). Broken line regression model of SGR and phenoloxidase activity suggested that the optimum dietary levels of encapsulated Na‐acetate, Na‐butyrate, Na‐lactate and Na‐propionate could be 30.7, 31.8, 31.4 and 33.5 g/kg, respectively, in crayfish reared in culture conditions. |
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| Keywords: | antioxidant enzyme crayfish encapsulated organic acids growth performance gut microbiota haemolymph |
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